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The International Space Station



The International Space Station
The International Space Station is the second home of humans in Earth orbit, which is considered an engineering masterpiece.

The International Space Station

The International Space Station, or ISS for short, is a multi-piece space structure that is placed in low Earth orbit and several elite astronauts live in it for a certain period of time, during various missions. The process of building the International Space Station started in 1998 and it is said that it can be used until 2028. As its name suggests, the International Space Station is a multinational project, and the cost of its construction and development is divided among several specific countries; But according to the statistics and evidence, it can be said that Russia and America are the main contractors of the project and provide most of the expenses related to the station. Every year, some astronauts are sent to the station and return to Earth to carry out some necessary research. The existence of the International Space Station is necessary to investigate the effects of living in space on the human body; Because soon man will travel to planets like Mars.

The International Space Station

The International Space Station has been constantly being completed during its mission. The first structure of this station was launched into orbit in 1998 and the last module was installed on the station in 2011. NASA, Roscosmos (Russian space agency), Japan Space Agency, European Space Agency, and Canadian Space Agency are among the main contractors of the station and each of them has sent astronauts to the station. The budget of this station is provided internationally and the member countries are obliged to allocate a certain amount of their budget to the International Space Station every year. The cost of building the International Space Station until the moment of installation of the last module was 150 billion dollars, and for this reason, it is considered the most expensive structure of the human hand.

The International Space Station is the second home of humans in Earth orbit. People who go to the station experience zero gravity and are affected by the conditions of space. One of the reasons humans are stationed in the station is to measure the effects of space conditions on their bodies. When humans want to travel to planets like Mars, they have months to reach their destination; Therefore, during this period, they live in special conditions that will definitely have effects on their bodies. For this purpose, conducting a series of experiments in the International Space Station can reduce the risks of space travel.

The International Space Station

The International Space Station is not the first station to be built in the Earth’s orbit, and before that, stations such as Mir, Salyut, Almaz, and Skylab were also built in the Earth’s orbit; But ISS is the largest and most advanced of them and its mission duration is longer than others. This station has certain intricacies that make it an engineering masterpiece. In this article, we intend to put the International Space Station under the microscope and take a close look at all the details of the most expensive human structure.

Read More: Receiving a message from a distance of 16 million kilometers from the earth


The history of the construction and development of space stations goes back to the time of the Cold War and the height of the space competition. When the Saturn 5 rocket was being developed by America and by Dr. Werner von Braun and his group, this German engineer always had the idea of ​​building a space residence in his mind. In the same years, in order to be able to explain this idea to people in a better way, Hanzmenda created cinematic works in which space stations were depicted. These stations were circular and rotating; Because in the hypothetical case, they should have created artificial gravity with their rotation. In these movies, many people traveled to the station and started businesses there; The ships also moved towards the station like the ships that dock at the port. A similar idea was recently portrayed in the movie Elysium.

These stations were like hotels on the way, and humans could go to the moon or Mars from there. This idea was very timeless, But that was exactly what Dr. Brown had in mind. This idea is not applicable even today despite the advances, But scientists have been able to implement the original idea of ​​building a space station, and this work was done for the first time by the Soviet Union. The first space station was launched in 1971, and since then, the United States and the Soviet Union have always had a station or stations in orbit. The first station that was placed in the earth’s orbit was the Salyut space station (Салю́т), which was considered a military scientific project the Soviet Union was very sensitive about it and tried not to reveal any details about it and not to be available to the Americans.

The International Space Station

After the Salyut space station, it was the Americans’ turn to enter this field. Skylab was the first American space station in Earth orbit, which was sent into space at once by the Saturn V rocket in 1973. The Salyut station was a multiple project, the first of which was called Salyut 1, and actually, this station was a combination of the Almaz and Soyuz spacecraft systems. Almaz was a military system designed for space purposes by the Soviet Ministry of Defense, But later its usage was changed and it became a part of Salyut 1 station.

After the Soyuz 11 mission, the Soviet Union launched another space station called Salyut 2, which unfortunately was unsuccessful and did not reach Earth’s orbit. After this failed mission, the Soviet Union launched the Salyut 3, Salyut 4, and Salyut 5 space stations, and after the launch, the astronauts connected to the station with the help of the Saiz spacecraft and stayed there for a longer period of time to carry out new missions. Salyut stations were only connected to Soyuz spacecraft and it was not possible to connect them to other types of spacecraft. In September 1977, the Salyut 6 space station was launched, which had two entrances and the unmanned Progress spacecraft could also dock with it. Salyut 6 continued to work until 1982, and then it was replaced by Salyut 7, which was the last station of the Salyut project.

Salyut 7 was one of the news-making and controversial stations. This station was launched in 1982 and hosted 11 astronauts for 800 days; But in the same year, the Salyut 7 accident happened and the station was out of Soviet control. The electrical system of this station failed due to the impact of several cosmic bodies, and the station began to rotate in the earth’s orbit and the process of falling towards the earth began. The Soviet Union, which was under international pressure at the time, decided to launch two astronauts on a Soyuz spacecraft during a hasty mission to manually dock the rotating station and return it to a stable state. These two Russian astronauts managed to connect to the station and recover it, and this rescue operation is one of the most impossible missions in the history of aviation. The Salyut 7 space station later paved the way for the formation of the Mir space station project.

The International Space Station

America, unlike the Soviet Union, did not invest much in the field of space stations, and before the development of the International Space Station, Skylab was the first and only American space station. Skylab was launched in 1973, But it was damaged during the launch and 2 of its solar panels were completely fragmented and another solar panel did not open completely. These events caused Skylab to have little electrical power in the circuit and the station’s temperature regulation system did not work well. To solve this problem, the United States launched the manned spacecraft Skylab 2 so that the astronauts could repair the station. These astronaut engineers were able to successfully repair the station bring it to a stable state and stay in the station for 28 days.

Orbital workshop, weatherproof module, multiple docking station, Apollo telescope unit, and Apollo spacecraft were among the constituent parts of Skylab. The Skylab 3 and 4 missions, whose crews stayed on the station for 59 and 84 days, respectively, docked with the station after the Skylab 2 mission. Skylab was not a permanent station, and the US intended to use it solely as a space laboratory to measure the effects of flights lasting a week to a month on the human body. Skylab 3 was the last mission to dock with the station, and the Skylab space station entered the Earth’s atmosphere much earlier than expected due to rapid orbital rotation caused by collision with intense solar activity and burned up in the sky over Australia.

Another space station was the Soviet Mir station, which was launched and assembled in 1986. Mir was considered the most advanced man-made space station at that time and was operational for 10 years. The first astronauts who went to the station were the same astronauts who performed the rescue operation of Salyut 7. These people stayed at Mir station for 75 days and then returned to Earth. The Mir space station consists of parts such as the life module (bathroom and kitchen, etc.), the mediating part, the assembly part, the Quantum 1 astrophysics module, the Quantum 2 airtight and scientific module, the Crystal technological module, the Specter module, the Periroda remote sensing module, The docking module was formed by the unmanned Progress spacecraft and the Soyuz spacecraft.

The International Space Station

In 1994, Russia allowed the United States to allow American astronauts to spend some time at the Mir station to prepare for the International Space Station. Worried about the high costs of maintaining the Mir station, Roscosmos decided to partner with NASA; But the Russian government did not agree and said that it is better to abandon the station so that all the focus is on the International Space Station. Mir was a permanent space station, But the Russian government decided to direct it to the ground and destroy it. Finally, in 2001, the remnants of the Mir space station fell into the South Pacific Ocean.

According to the information we have obtained, we now know that the ISS is the ninth habitable space station in Earth orbit, It was developed after Diamond, Salyut, Skylab, and Mir, and perhaps inspired by them. The process of building the International Space Station began in 1998; But the first astronauts who stayed there were launched into space during the Expedition 1 mission on November 2, 2000. Since then, more than 17 years have passed and this is the longest presence of a space station in low Earth orbit. Before the International Space Station, the record for the longest stay of a space station in orbit was held by the Mir space station with 9 years and 357 days. The cargoes required for the International Space Station are transported to the station with the help of spacecraft such as Russia’s Soyuz and Progress, America’s Dragon and Cygnus, Japan’s H-II, and Europe’s transfer system. Before the cancellation of the space shuttle program, it was also possible to connect these shuttles to the station. The International Space Station has hosted astronauts, cosmonauts, and tourists from 17 different countries.

According to the contract signed between NASA and Russia’s Roscosmos, it was decided that the International Space Station will be a laboratory in low Earth orbit, where necessary investigations will be carried out to improve future space travel. NASA had predicted that humans will travel to Mars in the future and dangers are threatening them; Therefore, it is necessary to measure the results of being in space on the body in the International Space Station so that there are no problems for astronauts in future trips. In 2010, the US Space Flight Agency announced that the ISS had more potential and could be used for educational purposes and to share information with the public in the form of television programs.

Construction of the station

The construction of the International Space Station officially began in November 1998. Russia was the first country to produce the initial modules of the station, and all of these modules, except for the Razovet module, were robotically connected in space. The other modules of the station were launched by the American space shuttles and connected by the shuttle crew using the Canadarm2 robotic arm. By June 5, 2011, when the construction process of the station was completed, 159 pieces had been connected during 1000 hours of spacewalk, and this was considered a record. 127 spacewalks were performed by the station’s crew, and the remaining 32 were performed directly inside the shuttles and airlocks. Scientists on the ground had to constantly calculate the station’s beta angle and provide it to the astronauts so that the work went as well as possible. Beta is the angle between the orbital plane of a satellite and the solar radiation vector and shows how much energy a satellite receives during solar radiation to generate electricity. For the engineers who were building the station in space, the beta angle was of particular importance; Because it showed how many hours they were exposed to sunlight during the docking operation, and if the beta was not calculated, the shuttle could not be placed correctly on some modules during some limited hours.

The International Space Station

The first module of the International Space Station is the Zarya module (Заря́) which was launched on November 20, 1998, by the Russian Proton self-propelled rocket. Zarya was a module that could provide the necessary propulsion power to be placed in the orbit, control the height, and also provide the necessary electrical power; unfortunately, it did not have enough facilities to be used for a long-term stay. Two weeks after Zarya, the United States launched the Unity module (Unity) in the STS-88 mission with the help of the space shuttle and several crew members. The Unity module was attached to the Zaria module by astronauts who performed several hours of spacewalk. Unity had two pressure-coupled adapters, one connecting to Zaria and the other to the space shuttle. At the same time, the Mir space station was still in orbit and could host the crew.

The International Space Station was uninhabitable for two years, and the Mir station was gradually decommissioned. On July 12, 2000, Russia launched the Zvezda (Zvezda) module into space. The Roscosmos space agency had planned Zivezda to deploy its solar arrays and communications antenna before connecting to Unity and Zaria. This module itself had a command center and was autonomous, But Zaria and Unity were controlled and commanded by ground stations. Zyuzda was the most advanced module to be attached to the ISS. After connecting Zyuzda to other modules, the task of controlling the overall structure of the station was taken from Zarya and given to Zyuzda. Zivzda was a large module where there were sleeping quarters for the crew, a kitchen, carbon dioxide scrubbers, humidifiers, oxygen generators, sports equipment, radio and television connected to the mission control system, etc. Zvezda was the module that made the ISS habitable for the first time.

The first crew of the International Space Station, in the form of the Expedition 1 mission and with the help of the Russian Soyuz TM-31 spacecraft, connected to the space station in November 2000. Late on the first day of the mission, astronaut Bill Shepard of NASA and cosmonaut Sergei Krikalyov of the Russian space agency, as two members of the Expedition 1 crew, announced in a radio message that they wanted to name the station Alpha. Alpha had previously been considered for the station’s naming, But America and Russia had in mind the name ISS. Now that the two astronauts had applied, NASA and Roscosmos decided to rename the Expedition 1 mission to Alpha. Shepard believed that they should name the entire station Alpha; Because alpha is always a reminder of being first. In a speech, he announced that this is the first experience of a long-term stay in space and that we are considered the pioneers of staying in space. NASA had agreed to some extent, But Russia said that this is not true and the Mir station has been habitable before, and if the name Alpha is to be chosen, Mir should be Alpha.

For two years after this mission, the station was still expanding. In 2001, a Soyuz rocket carried the Pierce Multiplexer into space. A pier is a connecting section that has vents to connect the manned Soyuz and the unmanned Progress spacecraft and acts as a trike. The space shuttles Atlantis, Discovery, and Endor also brought the Destiny Laboratory and the Quest airlock into space to dock with the station. In addition, for the first time, the Canadarm2 robotic arm and several other parts were also attached to the body of the station. Everything was going well and according to the plan until the explosion of the space shuttle Columbia disrupted the program. In 2003, the space shuttle Columbia exploded in the sky and killed all its passengers. This incident caused a two-year hiatus in NASA’s space shuttle program. The space shuttle program was suspended until 2005 when it was finally restarted with the launch of the space shuttle Discovery.

The process of assembling the modules of the space station started again in 2006 with the launch of the shuttle Atlantis in the STS-115 mission. During this mission, NASA attached the second set of solar arrays needed by the station to the main structure. The next three NASA missions also connected other body components and the third series of solar arrays to the station, and as a result, the power generation capacity of the station was completed. After Russia and America were sure about the power supply of the station, they started the process of sending the next modules. The Harmony Node and the Columbus Laboratory (belonging to the European Space Agency) were among the modules that were attached to the body of the station and other modules. Soon after the connection of these two modules, the Japanese Space Agency announced that the first part of the Kibo laboratory was produced and ready to be sent.

In March 2009, the STS-119 mission completed the construction of the subsystems and was able to install the fourth and final group of solar arrays on the hull of the station. The second and last part of Japan’s Kibo Laboratory was connected to the station by the STS-127 shuttle mission in July 2009, and then the Poisk module (По́иск), or the small research module, was launched by Russia. In February 2010, the STS-130 mission, carried by the space shuttle Endor, attached the third node, or Tranquility, to the station, along with the Cupola observation tower. A few months later, Russia also launched one of its last modules called Razvet (Рассве́т). Russia did not carry out the launch itself, but entrusted the task of the launch to the Atlantis space shuttle and paid the cost of the launch. Earlier, the US had financed the launch of the Proton rocket that launched the Zarya module into space in 1998.

The International Space Station

On its last mission in February 2011, Discovery delivered the Leonardo Pressurization Module to the station, and in the same year, the space shuttle Endor also docked the Alpha Electromagnetic Spectrometer during mission STS-134. As of June 2011, the space station consisted of 15 pressurization modules and an integrated structure, and member states declared that all major equipment was installed on the station and that anything launched after that would be considered auxiliary equipment. Currently, 5 other modules are in the launch queue. These modules are:

  • The Nauka module (Нау́ка), which is a Russian multipurpose laboratory, connects to the Zyuzda module.
  • The European Space Agency’s robotic arm
  • Узловой module, which is a Russian spacecraft
  • NEM-1 power supply module
  • NEM-2 power supply module

The Russian Space Agency has announced that the Nauka module will most likely be launched in the last quarter of this year along with the robotic arm of the European Space Agency. After the Nauka module docks with the space station, Russia will also launch the Yuzloy module to connect to one of the Nauka module’s docking ports. When these 5 modules are connected to the station, the total weight of the station will be more than 400 tons. The net weight of the station constantly changes over time; Because newer modules are always added to the station. By September 2011, when the construction of the station was completed, its total weight was 417 tons. Of course, this is considering only the weight of the station structure itself and ignoring the weight of water tanks, gas tanks, laboratory equipment, clothes and personal belongings of astronauts, food, connected spacecraft, and other things.

The International Space Station is a third-generation modular space station. A modular structure allows the body of the station to be changed to suit different missions and new parts can be added or removed from the structure. Also, the modular structure has flexibility and its shape is not static.

The main modules of the station

As mentioned earlier, the International Space Station is made up of several different modules; But some of these modules are original and other modules are installed on top of these modules. Zaria, Unity, Zyvesda, Destiny, Quest, Pierce and Poisk, Harmony, Tranquility, Columbus, Kibo, and Coppola are among the core modules of the International Space Station currently installed on the station. There are a number of other modules that are going to be connected to the station soon, which we will also mention. In the following, we will examine each of these modules and their features.

Zaria module

Zarya, which is also known by the Russian name Заря́ meaning dawn, is the first module of the International Space Station that was launched by the Russian Space Agency (Roscosmos) and placed in orbit. The task of Zaria was to provide electricity, propulsion, and positioning of the International Space Station in the early stages of construction and production. When the other modules were launched and attached to Zaria, Zaria had no special function and is now used as a storage area. Zarya is actually a more advanced version of the Russian TKS spacecraft that was used to connect to the Salyut space station. As mentioned, Zaria means dawn; Because it was supposed to usher in a new era in spaceflight. Zaria was built by a Russian company, But the main owner of that company was the United States of America.

The International Space Station

Initially, Zaria was supposed to act as one of the modules of the Mir space station; But unfortunately, Zaria was not ready until the Mir space station was stable. Zarya has the ability to maintain a station in orbit and, due to the batteries that are placed inside its body by default, it has the ability to provide power to one or more other modules until the solar arrays are launched. Zarya weighs 19,323 kg, is 12.56 meters long and 4.11 meters wide at its widest point, and is considered a medium module in terms of size. Zarya can be connected from three different parts, one of them is located exactly in the front part, another one is in the ground part and the other one is placed in the back part. The Unity module is connected to the Zarya’s front connector with the help of a push-fit adapter. The Zyuzda module is also connected to the end of Zarya, and its ground connection valve is also connected to the Soyuz and Progress spacecraft that come to the station. Not long ago, the Razovet module was attached to the downward docking port of Zarya, and now if a spacecraft arrives at the station, it must be attached to the Razovet module first.

Zaria has two solar arrays 10.67 meters long and 3.35 meters wide and 6 nickel-cadmium batteries that can produce 3 kilowatts of electricity. Zaria has 16 external fuel tanks that can hold 5.4 tons of fuel. Zarya has 24 large thrusters, 12 small thrusters, and two large engines that were used for the station’s orbital changes. Since the Zyuzda module connected with the station, Zarya’s engines were disabled; Because with Zyuzda, Zarya engines were no longer needed. Zarya’s fuel tanks are now used as a place to store the fuel needed by Zyuzda.

On November 20, 1998, Zarya was launched by a Russian Proton rocket from the launch pad of Cosmodrome 81 in Kazakhstan to an altitude of 400 km. Zarya was originally designed to have a useful life of 15 years and be able to fly autonomously for 6 to 8 months; But due to the delay in the launch of the Zyuzda module, Zarya had to move autonomously for more than two years. At first, Zaria’s battery charging circuits had problems; But gradually these problems were solved by Russian cosmonauts.

Unity module

The Unity module, also known as Node 1, is the first American module of the International Space Station launched by NASA. Unity uses a cylindrical design and can be connected to the station and other modules from 6 separate points. Unity is 4.57 meters in diameter and 5.47 meters long and was jointly developed by NASA and Boeing at the Marshall Space Flight Center in Alabama. Unity is the first docking module of the space station, followed by Harmony and Tranquility modules.

The International Space Station

Unity was the main cargo of the space shuttle Endor, which was launched as part of the STS-88 mission. This mission was the first space shuttle mission to connect to the station. In space, before reaching the Zaria module, the rear end of the Unity module was attached to the Endor shuttle, and then they moved towards the Zaria module until they finally managed to attach the upper part of the Unity to the front section of the Zaria. Unity has 2 axial connection systems and 4 radial connection systems, and in addition to connecting to Zaria, it is connected to parts such as Destiny Lab, Z1 Integrated Structure, PMA-3 Pressure Connecting Adapter, Quest Airtight Knee, Leonardo Multipurpose Module and Raffaello Multipurpose Module Is. During the STS-120 mission, the Harmony module was also attached to the Unity side port. Tranquility and Coppola also docked with the Unity module during the STS-130 mission.

Some of the essential resources of the space station, such as fluids, life support systems, electrical systems, and data support systems, are precisely located in Unity to provide the necessary conditions for living in different parts of the station. More than 50,000 mechanical parts, 216 liquid and gas transmission lines, and 121 hidden and covered electrical cables (6 miles of cable) have been installed in the Unity node. The overall material of the module is aluminum and stainless steel.

Zvezda module

Zvezda, also known by the Russian name Звезда́ meaning star, is a Russian command and service module. Zvezda, the third module and one of the most important parts of the International Space Station, was able to provide everything needed to support life on the station after the launch. Zvezda was launched into space by a Russian Proton rocket on July 12, 2000, and connected to the Zarya module on July 26 of the same year. The Zyvezda module was built by the Russian company RKK Energia, which is one of the main contractors of the International Space Station.

The main frame of the Zyuzda structure was first built in the mid-1980s and was to be used as the core of the Mir-2 space station. In fact, for a while, this module was called Mir-2. The construction of the main part of this frame was completed in 1985 and the equipment was installed on it in October 1986. Zyuzda has a cylindrical design and is built in such a way that the crew can live and work in it. Zyuzda has a total of four connecting valves that are used to connect to other masoles. The total weight of Zyuzda is 18051 kg and it is 13.1 meters long. Solar panels are also installed on Zivzda, which are 29.7 meters long when opened.

The International Space Station

Zivzda has 14 windows, two of which have a diameter of 230 mm, and two crews sleep in the compartments. Six other windows with 230 mm diameter glass are located on the lower floor of Zyuzda and face the ground. One of the windows, which has a diameter of 410 mm, is located in the Zyuzda workshop. Other Zyuzda windows are placed in the transfer chamber and the laboratory part, respectively.

On July 26, 2000, Zyvezda successfully docked with the Zarya module, officially becoming the third module of the ISS. On September 11, 2000, the two crews of the STS-106 mission completed the final stages of connecting Zarya and Zivzda. This find was made during a spacewalk of 6 hours and 14 minutes by American astronaut Ed Lowe and Russian cosmonaut Yuri Melenchenko. They successfully connected 9 cables between Zarya and Zivzda. Zivzda was a module where there were places for the crew to sleep, a kitchen, carbon dioxide scrubbers, humidifiers, oxygen generators, sports equipment, radio and television connected to the mission control system, etc.

As Russia faced financial difficulties, it did not produce any supporting versions of Zyuzda; Therefore, the risk of launch was greatly increased. NASA decided to produce the Interim control module, which could launch this module as a backup if something went wrong during the launch. Fortunately, the launch was successful and Zyuzda did not have the slightest problem.

Destiny module

Destiny, also known as the American Laboratory, was the first American laboratory module that was attached to the space station. Dastini was connected to the Unity module by connecting valves. Destiny is NASA’s first research laboratory in Earth orbit after the destruction of the Skylab space station. The design and production of this module are under the responsibility of Boeing and the construction process of this 16-ton structure began in 1995 at the Marshall Space Flight Center. Destiny was transferred to the Kennedy Space Center in Florida in 1998; But due to interruptions in NASA’s plans and conducting a series of necessary tests, the launch was postponed until 2000. The Destiny Module was launched into space on February 7, 2001, by the Space Shuttle Atlantis as part of the STS-98 mission.

The International Space Station

On February 10, 2001, Destiny arrived at the space station and was docked with the Unity module by the Canadian of the space shuttle Atlantis. Destiny has an aluminum structure and uses a cylindrical design. This module is 8.5 meters long and 4.3 meters in diameter. The front part of Destini is connected to the Unity module and its end part is also connected to node number 2. A glass window with a diameter of 510 mm is also placed on one side of the door that has a view of the ground. Destiny’s total weight is declared as 14520 kg, which is considered average.

Quest module

The Quest airlock knee, formerly known as the airlock knee module, is the first airlock of the International Space Station. Quest is designed in such a way that astronauts can enter space directly in space and stabilize the air pressure. In this airlock, astronauts can enter in Russian and American clothes and there is no problem in this regard. Until the launch of this module in 2001 and in the form of the STS-104 mission, Russian astronauts who used their special suits had to enter the station through the Zyuzda module, and American astronauts only entered the space shuttle connected to the station. The station could enter the interior of the station.

The International Space Station

The Quest module consists of two main parts; One for keeping the spacesuits and the other for when the astronauts want to leave or enter the station. These two parts are completely isolated from each other. It was necessary to build the quest module; Because the American astronauts, who had their own spacesuits, could not enter the station through the Russian Mazul Zyuzda airlock, and it was not possible to enter from other parts either.

Pierce and Poisk modules

Пирс and По́иск are two Russian airlock modules, each of which has two different valves. Pierce was launched in August 2001 and provided a docking station for the Soyuz and Progress spacecraft. It also made it possible for Russian cosmonauts wearing Orlan-designed spacesuits to enter and exit the station. Pierce was supposed to be separated from the station by the Progress spacecraft in 2017 and fall towards the Earth to make room for the Russian Nauka laboratory; Lamel, due to the delay in the construction of the Naoka laboratory, the separation process of Pierce was also postponed until the end of 2018.

Poisk is another Russian docking module that was launched and attached to the station in 2009. Poisk was the first Russian module of the station to be launched after 2001. Poisk generally uses Pierce’s design. Pierce is connected to the lower part of the Zyuzda module, But Poisk is attached to its upper part. Poisk in Russian means search and discovery, and for this reason, it has a series of scientific tools and equipment.

Harmony module

Harmony, also known as Node 2, is the second American node of the International Space Station. This module has the ability to provide electricity and electronic data of the bus, and due to having 6 connection valves, it can be connected to different parts of the station. European Columbus module, Japanese Kibo Labs connected to Harmony Radial Valves. Harmony’s upper and lower hatches are also used to dock spacecraft arriving at the station. Dragon, Cygnus, and HTV spacecraft are typically attached to these vents. By 2011, space shuttles were also docked at the bottom of Harmony.

The International Space Station

This module was initially known as node number 2; But in March 2007, NASA named it Harmony. At that time, NASA held a name competition among 32 American states, in which 2,200 kindergartens participated, and Harmony was chosen among the proposed names. At that time, NASA presented the children with information about the space station and asked them to build a small model and choose a name for it. Harmony in the term means the center that hosts scientific works. Harmony was launched on October 23, 2007, as part of the STS-120 mission and arrived at the station 3 days later.

Tranquility module

Tranquility, also known as Node 3, was built by the European Space Agency and the Italian Space Agency. In February 2010, NASA sent this module into space with the help of a space shuttle. The task of controlling and commanding this module was assigned to NASA from the very beginning. This node has 6 connecting valves, But one of them is still inactive because the rocket it was supposed to connect to was never launched.

In this node, more necessary life support equipment is placed and there is also a water purification system. The water purification system of this node can turn the astronauts’ urine into drinking water again if needed. The crew can use the oxygen generators in this node when necessary. The connecting valves of this node are each connected to a part. The first valve is connected to the Unity module, the heart of the station, and the others are connected to the Assonardo module, the Bigelow expandable module, the pressure connection valve number 3, and the Copola module.

Columbus module

Columbus is the first European research laboratory of the space station. In this module, there is a small laboratory and facilities for biological research and fluid physics. Several special bases are placed on the outside of this module, on which equipment can be installed to provide data and electrical energy necessary for external laboratory equipment. The European Space Agency plans to expand the space station to study quantum physics and cosmology. The European Space Agency is always trying to improve the life support systems of this module and make it still usable for the next 20 years.

The International Space Station

Kibo Laboratory

Kibo is a Japanese laboratory and also the largest module of the International Space Station. Scientists use this laboratory to study space medicine, biology, earth observation, materials production in space, biotechnology, and the development of communication technologies. In this laboratory, there is equipment that can be used to grow flowers in space. In August 2011, the MAXI observatory was installed on the Kibo module. The observatory uses the orbiting orbit of the space station to take X-ray images of the entire sky. This observatory was able to observe a star being swallowed by a black hole for the first time.

The International Space Station

This module consists of 23 different sections, 10 of which are laboratory sections. This module also has an air seal for testing. Another pressurized module is attached to the top of the Kibo, which mostly serves as a compartment for additional equipment.

Copula module

The cupola is an observatory that has 7 windows and is used to observe the Earth and connect other spacecraft. The name of this module is inspired by the Italian word copola which means dome. The construction of the Coppola module was done by NASA and Boeing; But due to lack of funds, the work was stopped. Sometime later, in an agreement between NASA and the European Space Agency, this organization agreed to pay part of the cost, and thus the construction process resumed in 1998.

The International Space Station

Boeing was no longer the contractor for this project and its construction was handed over to the Italian Space Agency. This module has 7 small glass windows and a circular window with a diameter of 80 cm, which is the largest window of the space station so far.

The future of the station

As it was said at the beginning, the station is supposed to remain operational until 2028; on the other hand, NASA will probably stop cooperating with the project until 2024, and stopping NASA’s cooperation will probably mean the end of the space station. It was in 2014 that the US Congress announced that it had to decide on the International Space Station and see if it could still be funded. Finally, in the same year, Congress announced that it would retire the International Space Station in 2024 and not fund it. With these interpretations, there are only six years left in the life of the International Space Station; Only seven years, and then it is not clear what is going to happen.

NASA spends the other half of its budget on rover missions, sending humans to Mars or sending to an asteroid. If NASA is to expand its projects and enter space exploration into a new field, it will no longer be able to allocate three to four billion dollars of its annual budget to the International Space Station. Of course, this is not a decision made by NASA; Rather, Congress and especially the White House decide how much funding NASA receives.

As mentioned at the beginning, one of the ways that NASA can investigate how to send humans to other planets is to test this work on the International Space Station. This station has a microgravity environment (weightlessness of humans and other objects) and is outside the Earth’s atmosphere; This means that scientists of all sciences can conduct their own experiments on the station to observe the effects of space on everything. Also, in this station, the effects of long-term human stay in a zero-gravity environment are measured. Recently, some politicians have said whether all the funds allocated to the International Space Station were worth it or not; Unfortunately, it seems that the United States Congress does not have a very good record of supporting applied sciences.

The International Space Station

No one is saying that the International Space Station should be supported and funded forever. With the growing private sector and large companies such as SpaceX, Blue Origin, and Virgin Galactic, we hope that one day the International Space Station will be supported by the private sector. There are some companies that are interested in making equipment for use in space; These companies can pay huge sums of money just to be able to test their equipment on the International Space Station. Maybe Elon Musk will decide to add this station to his company’s subsidiary; no one knows However, in the next two years, 5 more modules will be connected to the International Space Station, which will be used for different applications; But different countries are still waiting for NASA’s green light for the station to be operational by 2028.


As mentioned at the beginning, the International Space Station is the most expensive man-made integrated structure. In 2010, it was announced that the total cost of the station is likely to be around $150 billion, of which $72.4 billion belongs to NASA. The Russian Space Agency spent $12 billion, the European Space Agency $5 billion, the Japanese Space Agency $5 billion, and the Canadian Space Agency spent $2 billion to build the station. The cost of launching each shuttle was 1.4 billion dollars, and by calculating the 36 launches and the cost of construction, it can be said that this process alone cost 50.4 billion dollars. With another calculation, we can find out that in 15 years, the daily cost of each crew member at the station was 7.5 million dollars.

Interesting Facts

  • 16 countries are members of the International Space Station project. These countries are the United States of America, Russia, Canada, Japan, Belgium, Brazil, Denmark, France, Germany, Italy, Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom.
  • The International Space Station orbits at a speed of approximately 8 kilometers per second, which means that the space station orbits the Earth once every 90 minutes.
  • You might think that your apartment or house has more space than the space station, But it is interesting to know that this station has a total length of 109 meters provides a lot of space for the crew and has a lot of rooms.
  • The International Space Station is the largest man-made structure in space and has a total of 1141829 cubic centimeters of internal space.
  • There are only two toilets throughout the station. The water used in these services, together with the astronauts’ urine, is re-purified and turned into drinking water.
  • Being in space does not mean being safe from computer viruses. There are 52 computers in the space station, each of which has been infected with the virus more than once. For the first time, these computers were infected with a worm designed to steal computer game passwords.
  • The International Space Station is the only place in space where you can smell the smallest things. One of the astronauts said that he felt a special smell like the ionization of metal. Such a smell is rarely felt on earth.
  • The International Space Station is the brightest object in the night sky after the Moon and Venus, and if the weather is clear, you can see the space station with the naked eye.
  • Being in space destroys bone tissue and muscles. Therefore, astronauts should exercise two hours a day to avoid any problems.
  • In total, 12.87 kilometers of cables have been used in the space station, which is more than the cables used in New York’s Central Park.
  • Astronauts eat only three meals a day and do not know if they are sitting or not while eating; Because sitting in the space makes no sense at all, and there are no special seats in the station’s kitchen.


In general, it can be said that the International Space Station is a masterpiece of human engineering in space. This station was built thanks to the great experience of Russia and America and it allocates a lot of budget annually. The existence of this station in the Earth’s orbit is very necessary; Because in the near future, humans will travel to the moon, Mars, and other planets, and they must make the necessary preparations in the space station. It is still unclear what will happen to the International Space Station and what NASA will decide about it.

With the growth of private organizations such as SpaceX, it seems that this project will be left to the private sector and NASA will focus on other sectors. However, the space station is currently the only place in space where humans can go; Because humans haven’t left Earth’s lower orbit for almost 50 years.

The International Space Station

The International Space Station owes its existence to stations such as Salyut, Almaz, Mir, and Skylab, and maybe if these stations were not built, the ISS would not have progressed to this extent. Of course, we should not forget Dr. Werner von Braun, the creator of the Southern 5 rocket; Because he proposed the idea of ​​building a space station for the first time. We are still in the early stages of space station development. The International Space Station has made significant progress over Salyut, Skylab, and Mir; But we still have a long way to go to make the big space stations and colony-centered ones a reality as written by science-fiction writers.

It seems that in the future space stations will have artificial gravity, and none of our stations currently have gravity. Another reason is that we lack the technology to actually spin a massive system like a space station, so we can’t create artificial gravity.


Pluto; Everything you need to know




Pluto is a dwarf planet and the largest mass in the Kuiper belt, which was once known as the ninth planet in the solar system; But later he lost this position.

Pluto; Everything you need to know

Pluto or Pluto is the largest known dwarf planet in the solar system, which used to be the ninth and outermost planet in the solar system. This strange world is located in the Kuiper Belt; A region beyond Neptune’s orbit with hundreds of thousands of rocky and icy bodies each more than 100 kilometers across, as well as a trillion or more comets.

Pluto was reclassified as a dwarf planet in 2006 and lost the title of ninth planet. The demotion of Pluto was a controversial event and provoked serious discussions in the scientific community and among people.

Table of Contents
  • How was Pluto discovered?
  • What does Pluto look like?
  • What is Pluto made of?
  • Orbital features of Pluto
  • Interesting facts about Pluto’s orbit
  • Why is Pluto no longer a planet?
  • Does Pluto have moons?
  • Journey to Pluto
  • Pictures of Pluto and its moons

How was Pluto discovered?

Percival Lowell, an American astronomer, first proposed the existence of Pluto in 1905 when he observed strange deviations in the orbits of Uranus and Neptune. Lowell thought there must be another object whose gravity was affecting the ice giants, causing them to misalign their orbits. Lowell predicted the position of the mysterious planet in 1915, But he died 15 years before its discovery. Finally, based on the predictions of Lowell and other astronomers, Clyde Tamba discovered Pluto in 1930 at the Lowell Observatory in Arizona.

Clyde Tamba discovered the dwarf planet Pluto
Clyde Tamba, discoverer of the dwarf planet Pluto.

Pluto was named by the suggestion of Venisha Burney , an 11-year-old child from England. With the news of the discovery of the ninth planet, Venisha suggested to her grandfather that the name of the god of the underworld in Roman mythology be placed on it. His grandfather then passed the suggested name on to the Lowell Observatory. Pluto is also considered to be a tribute to Percival Lowell because it contains the first two letters of Percival Lowell’s name.

What does Pluto look like?

Because Pluto is so far from Earth, little was known about the dwarf planet’s size or surface condition until 2015, when NASA’s New Horizons spacecraft flew past it. New Horizons showed that Pluto, with a diameter of 2,370 kilometers, is less than one-fifth the size of Earth and only about two-thirds the size of our planet’s moons.

New Horizons’ observations of Pluto’s surface revealed various surface features; Among the mountains whose height reaches 3500 meters and are comparable to the Rocky Mountains on Earth. Although frozen methane and nitrogen cover most of Pluto’s surface, these materials are not strong enough to support such high peaks; As a result, scientists believe that the mountains were formed on a bed of water ice.

The surface of Pluto as seen by the New Horizons spacecraftThe surface of Pluto was seen by NASA’s New Horizons spacecraft in July 2015.

Pluto’s surface is covered with an abundance of frozen methane, But New Horizons scientists have observed dramatic differences in the way light reflects off this icy surface across the surface of the dwarf planet. They have observed features similar to Earth’s ice sheets or erosion features in Pluto’s mountainous regions. These surface effects are much larger on Pluto; As it is estimated that their height is 500 meters; While the size of ground samples is only a few meters.

Another distinctive feature on Pluto’s surface is a large heart-shaped region known informally as the Tamba region. The left side of this area (the area that takes the shape of an ice cream cone) is covered with frozen carbon monoxide. Scientists have detected other changes in the composition of surface materials in the “heart” of Pluto.

At left center of the Tamba region is a very flat area that the New Horizons team has informally named the “Sputnik Plateau” in honor of Sputnik, the first artificial satellite to orbit Earth. This region of Pluto’s surface does not have craters caused by meteorite impact; A feature that shows that the Sputnik Plateau is geologically a very young region that is not more than a hundred million years old. It is possible that this area is still being formed and changed by geological processes.

Pluto’s ice plains show dark streaks several kilometers long that lineup. It is possible that these lines were formed by strong winds that blow on the surface of the dwarf planet. The Hubble Space Telescope has also obtained evidence that Pluto’s crust could contain complex organic molecules.

Pluto’s surface is one of the coldest places in the solar system. The temperature there can drop to minus 226 to minus 240 degrees Celsius. Comparing images taken of Pluto at different times showed that the dwarf planet appears to have become redder over time, possibly due to seasonal changes.

Pluto may have a subsurface ocean now or may have had one in the past. However, there is still no consensus on this. If an ocean had already formed under the surface of Pluto, it could have greatly influenced the history of this dwarf planet. For example, scientists believe that the Sputnik Plateau region grew so heavy over time as the ice mass increased that it overturned Pluto and brought its axial tilt to its present size (about 120 degrees). According to researchers, the subsurface ocean is the best explanation for this phenomenon. If Pluto has a liquid ocean and enough energy, it could be a haven for life.

What is Pluto made of?

Some of the elements that make up Pluto, according to NASA, are as follows:

Composition of the atmosphere: methane and nitrogen. New Horizons observations show that Pluto’s atmosphere extends up to 1,600 km above the surface of this dwarf planet.

Magnetic Field: Scientists still don’t know if Pluto has a magnetic field or not, But the dwarf planet’s small size and slow rotation suggest that such a field is weak or non-existent.

Chemical composition: Pluto is probably composed of a mixture of 70% rock and 30% water ice.

Internal structure: The dwarf planet probably has a rocky core surrounded by a mantle of water ice, and unusual frozen elements such as methane, carbon monoxide, and nitrogen cover its surface.

Orbital features of Pluto

Pluto’s highly elliptical orbit can take it over 49 times the distance from Earth to the Sun. Because the dwarf planet’s orbit is highly eccentric, or non-circular, Pluto’s distance from the Sun can vary dramatically. The dwarf planet was actually closer to the Sun than Neptune for 20 years of its 248-year orbital period, giving astronomers a rare opportunity to study this small, cold, and distant world.

As a result of such an orbit, after being considered the eighth planet from the Sun for 20 years, Pluto passed the orbit of Neptune in 1999 and became the farthest planet from the Sun until it was finally demoted to a dwarf planet in 2006.

As Pluto moves closer to the Sun, its surface ice melts, temporarily forming a thin atmosphere composed mostly of nitrogen and some methane. The insignificant gravity of Pluto, which is a little more than one-twentieth of the gravity of the Earth, causes this atmosphere to expand to a much higher height compared to the Earth’s atmosphere.

As the dwarf planet moves farther from the Sun, much of its atmosphere appears to freeze and disappear. However, when Pluto has an atmosphere, it can probably experience strong winds. This atmosphere also has changes in brightness, which can be caused by gravity waves or airflow over the mountains.

Although Pluto’s atmosphere is too thin to allow liquids to flow today, liquid elements may have flowed on the dwarf planet’s ancient surface in the past. New Horizons captured an image of a frozen lake in the Tampa area that appeared to have ancient waterways nearby. At one point in its history, Pluto could have had an atmosphere almost 40 times thicker than that of Mars.

Artist rendering of NASA's New Horizons probeArtist’s rendering of NASA’s New Horizons spacecraft.

In 2016, scientists announced that they may have observed clouds in Pluto’s atmosphere using data from New Horizons. The researchers saw seven bright objects that were located near the boundary between light and dark. This area is usually where clouds form. These possible clouds were all at low altitudes and almost the same size, which indicates that they are separate complications. The composition of the clouds, if they really exist, would probably be acetylene, ethane, and hydrogen cyanide.

Interesting facts about Pluto’s orbit

  • Pluto’s rotation is retrograde compared to other worlds in the solar system; This means that the dwarf planet rotates backwards and from east to west.
  • The average distance from the sun: 5,906,380,000 km or 39.4 astronomical units.
  • Periphery (shortest distance to the Sun): 4,434,987,000 km or 30.1 AU.
  • Apogee (farthest distance from the Sun): 7,304,326,000 km or 48 AU.
  • Pluto’s orbital path around the Sun is not in the same plane as the eight planets of the solar system; Rather, it is located at an angle of 17 degrees.
Pluto's orbit around the Sun compared to the planets of the Solar SystemPluto’s orbit around the Sun compared to other planets and the asteroid belt.

Why is Pluto no longer a planet?

Those who went to school until 17 years ago and before that, had learned in textbooks that Pluto is the ninth planet of the solar system. But in August 2006, the International Astronomical Union (IAU) downgraded Pluto to a “dwarf planet”. This meant that from then on, only the rocky worlds of the inner solar system and the gas giants of the outer reaches of the planet were considered.

The “inner solar system” is a region of space smaller than the radius of Jupiter’s orbit around the Sun. This range includes the asteroid belt as well as rocky planets such as Mercury, Venus, Earth, and Mars. Gas giants including Jupiter, Saturn, Neptune, and Uranus also form the outer limits of the solar system. As a result, now we have eight planets instead of nine.

According to the IAU definition, a “dwarf planet” is a celestial body that orbits directly around the Sun and has enough mass to be controlled by gravitational forces rather than mechanical forces, and as a result, is elliptical in shape; But it doesn’t clear the surrounding area from other objects. The three IAU criteria for a planet are as follows:

  • It revolves around the sun.
  • It has cleared the area around its orbit.

Pluto only meets the above two conditions and does not meet the third criterion, and in all the billions of years it has existed at this point, it has not been able to clear its vicinity. You may ask, what does “clearing the surrounding area of ​​other objects” mean? This condition means that the planet is dominated by gravity and there is no other body of similar size in its vicinity, except for moons or objects that are influenced by its gravity; While Pluto shares its neighborhood with Kuiper belt objects like plutinos.

Some scientists in recent years have demanded that by changing the definition of a planet, Pluto will return to the group of planets in the solar system. However, if this happens, the number of planets in our cosmic neighborhood may exceed the current number.

Does Pluto have moons?

Pluto has five moons: Charon, Stokes, Nyx, Cerberus, and Hydra, of which Charon is the closest moon to Pluto and Hydra is the farthest.

In 1978, astronomers discovered that Pluto has a very large moon, almost half the size of the dwarf planet itself. This moon was named Charon or Kharon, inspired by the spirit-carrying creature in Greek mythology that led souls to the underworld.

Because Charon and Pluto are so similar in size, their orbits differ from those of most of the planets and their moons. Much like binary star systems, Pluto and Charon both orbit a point in space that lies between them. For this reason, scientists refer to Pluto and Charon as a binary dwarf planet, binary planet, or binary system.

Pluto and its moon CharonComposite of color-enhanced images of Charon (top left) and Pluto (bottom right) taken by the New Horizons spacecraft in 2015.

Pluto and Charon are only 19,640 kilometers apart, or less than the distance between London and Sydney by plane. Charon’s orbit around Pluto takes 6.4 Earth days, and one Pluto revolution (one Pluto day) takes the same amount of time. The reason for this is that Charon hovers over the same point on Pluto’s surface, and the same side of the moon is always seen from the dwarf planet. This phenomenon is called fatal lock.

While Pluto has a reddish hue, Charon appears more grayish. This moon may have contained a subsurface ocean in the early days of its formation; But today, it probably cannot support such a complication. Compared to most of the planets and moons of the solar system, the system of Pluto and Charon is turned sideways with respect to the Sun.

New Horizons observations of Charon revealed the existence of valleys on the moon’s surface. The largest Sharon valley is 9.7 km deep, and a large mass of rocks and depressions stretches 970 km in the middle of the moon. A part of the moon’s surface near one pole is covered with much darker material than the rest.

Much of Charon’s surface is similar to Pluto’s crater-free regions, indicating that the moon is quite young and geologically active. Scientists have observed evidence of landslides on Charon’s surface, the first observation of such phenomena in the Kuiper Belt. The moon may also have its own form of plate tectonics; A phenomenon that causes geological changes on earth.

In 2005, in preparation for NASA’s New Horizons mission, scientists photographed Pluto using the Hubble Space Telescope and found two other small moons of this dwarf planet. These moons, named Nyx and Hydra, are two and three times more distant from the dwarf planet than the distance between Charon and Pluto. Based on New Horizons measurements, the length and width of Nix are estimated to be 42 and 36 kilometers, respectively; While Hydra is 50 km long and 30 km wide. It is likely that the surface of Hydra is mainly covered by water ice.

Pluto and its moons from the Hubble Space TelescopePluto and its moons from the Hubble Space Telescope.

Using the Hubble telescope, scientists discovered Pluto’s fourth moon, Herbrus, in 2011. This moon has a two-part shape, the big part is about 8 km long and the small part is about 5 km wide. On July 11, 2012, a fifth moon named Stokes (with an estimated diameter of 10 km) was discovered, further fueling the debate over Pluto’s planet status.

The main hypothesis for the formation of Pluto and Charon is that the nascent Pluto had a surface collision with another body of its size. According to this idea, most of the combined material of the two bodies became Pluto and the other remnants formed Charon. The other four moons may have formed from the same collision that created Charon.

Journey to Pluto

The New Horizons spacecraft is the first probe to closely study Pluto, its moons, and other Kuiper Belt worlds. The spacecraft was launched in January 2006 and successfully made its closest approach to the dwarf planet on July 14, 2015. The New Horizons probe is carrying some of the ashes of Pluto discoverer Clyde Tamba.

Limited knowledge of the Pluto system created unprecedented risks for the New Horizons probe. Before the mission launch, scientists knew of only three moons around Pluto. Herbrus and Stokes’ discovery during the spacecraft’s journey fueled the idea that more unseen moons may be orbiting the dwarf planet. Hitting these hidden moons or even small debris could seriously damage the spacecraft. However, the New Horizons team equipped the space probe with tools to protect it during its journey.

In October 2015, New Horizons made history by sending the first close-up images of Pluto and its moons. You can see these amazing pictures at the end of the article.

Currently, no other mission after New Horizons is officially planned to visit Pluto; But at least two conceptual designs are under study. In April 2017, a workshop was held in Houston, Texas to discuss ideas for the next Pluto mission. Possible goals discussed by the team for such a mission include mapping the surface with an accuracy of 9 meters per pixel, observations of Pluto’s smaller moons, how Pluto changes as it rotates on its axis, and topographic mapping of regions darkened by the dwarf planet’s axial tilt. They are long-term.

New Horizons principal investigator Ellen Stern believes that if an orbiter were sent to study Pluto, we could map 100 percent of the dwarf planet, even the surfaces in total shadow. New Horizons data indicated the possible existence of a subsurface ocean on Pluto, and researchers believe that the orbiter mission can also find evidence of such a complex.

Pictures of Pluto and its moons

Blue haze surrounding the dwarf planet PlutoAfter passing by Pluto, New Horizons looked back to photograph the blue dust surrounding the dwarf planet.
Charon is the largest moon of PlutoEnhanced color image of Charon, Pluto’s largest moon.
Snakeskin texture on part of Pluto's surfaceEnhanced color image of the “snakeskin” texture on part of Pluto’s surface.
The edge of the Sputnik Plateau on PlutoColor-enhanced image of the edge of the Sputnik Plateau, the icy plain that forms the left side of Pluto’s heart-shaped region.
Pluto's atmospheric dust over its rugged mountains and icy plainsPluto’s atmospheric dust over the rugged mountains and icy plains of this dwarf planet.
A partial view of the sunset on PlutoA partial sunset view shows rugged mountains with a maximum height of 3,350 meters.
Pluto's Sputnik PlateauSputnik plateau. The images used to make this composite photo were taken from a distance of 80,000 km.
Nix, Pluto's moon, from the perspective of New HorizonsLow-resolution image of Nix, a moon of Pluto.
Pluto's moon Hydra as seen by New HorizonsLow-resolution image of Hydra, Pluto’s moon.

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Why was Pluto removed from the list of planets in the solar system?




More than 17 years have passed since the demotion of Pluto from a planet to a dwarf planet, But experts and the public still debate Pluto’s status and planet definition.

Why was Pluto removed from the list of planets in the solar system?

Our understanding of the solar system changed forever on August 24, 2006. At that time, the International Astronomical Union (IAU) researchers agreed to reclassify Pluto, changing the status of this object from a planet to a dwarf planet. This decision provoked a lot of anger and caused the textbooks to be rewritten. The demotion of the former ninth planet of the solar system is still controversial after more than 17 years.

Currently, the discussion about Pluto shows the problems in defining the concept of “planet”. The International Astronomical Union defines a planet as a celestial body that orbits the Sun with a nearly spherical appearance and, in most cases, clears the vicinity of its orbit of debris from other bodies. However, this set of criteria has not been universally agreed upon.

Earth and even Jupiter, despite their large size, have not cleared many asteroids from their orbital regions. In addition, there are small worlds such as Ceres that are spherical and revolve around the Sun, and are not considered planets.

Table of Contents
  • After all, what is a planet?
  • A planetary puzzle
  • NASA’s New Horizons mission and the debate over the planet again
  • Can Pluto become a planet again?
  • What is the significance of Pluto being a planet?

Pluto’s demotion raises larger issues about how to define everybody in the solar system, or even space more generally. This incident shows that science sometimes cannot divide objects into easy categories; Because if the definition of planet is expanded again, it is not clear how we should evaluate the numerous non-spherical bodies that orbit the Sun. Decisions about this may even call into question the asteroid belt (the huge band of small objects between Mars and Jupiter). Or what happens if a planet somehow breaks into pieces?

The discussion about Pluto shows the problems in defining the concept of “planet”.

Meanwhile, while the Pluto debate began almost 20 years ago, many still don’t fully understand all the controversy and why Pluto lost its planetary status. But the change in the number of planets in the solar system from nine to eight (at least according to the standard IAU definition) was long in the making and highlighted one of science’s greatest strengths: the ability to change seemingly fixed definitions in light of new evidence.

After all, what is a planet?

The word planet in English (Planet) goes back to ancient times and is derived from the Greek word Planetes meaning “wandering star”. The five classical planets—Mercury, Venus, Mars, Jupiter, and Saturn—are visible to the naked eye and move in strange paths across the sky compared to the much more distant background stars.

After the advent of telescopes, astronomers discovered two new planets, Uranus and Neptune. These two distant worlds are very dim and cannot be seen with the naked eye. It should be kept in mind that the discussed definition of a planet follows the Greek-Roman tradition and the definitions of the International Astronomical Union are based on it. In ancient times, the planets were observed with the naked eye all over the world and had different names in each culture.

When astronomers discovered Ceres in the asteroid belt in 1801, it was classified as a “planet” by the scientific community at the time. But the situation began to change; Because further measurements showed that Ceres is smaller than any other planet seen so far. This mass then entered a group of rocky bodies called “asteroids”, of which we now know hundreds of thousands of examples in the asteroid belt alone. Today, Ceres is known as a dwarf planet.

Comparing the size of Earth and Moon with Pluto and CharonSize comparison of Pluto and its moon Charon (bottom right) with the Moon and Earth.

Pluto was discovered and classified as a planet in 1930 (11 years after the founding of the International Astronomical Union). At the time, Clyde Tamba of the Lowell Observatory in Arizona compared photographic plates of the sky on separate nights and noticed a small dot moving back and forth across the starscape. However, the latest candidate for the ninth planet of the solar system was immediately considered a strange object. Pluto’s orbit is so elliptical, or eccentric, that it brings the object closer to the Sun than Neptune in 20 years of its 248-year journey. Pluto’s orbit is also tilted relative to the ecliptic, or the plane on which the other planets in the solar system rotate.

If Pluto is a planet, then is Eris also a planet?

In 1992, scientists discovered the first Kuiper Belt object named 1992 QB1. This small body orbits the Sun in the vicinity of Pluto and beyond the orbit of Neptune. Soon many similar objects were discovered, and a belt of small, icy worlds similar to the asteroid belt between Mars and Jupiter was revealed. Pluto remained king of this region until, in July 2005, astronomers discovered the distant object Eris, which was initially thought to be larger than Pluto.

A planetary puzzle

After the discovery of Eris, researchers had to ask themselves these questions: If Pluto is a planet, then is Eris also considered a planet? What about all those other icy bodies in the Kuiper Belt or smaller bodies in the Asteroid Belt? Where exactly is the dividing line for classifying an object as a planet? A word that once seemed straightforward and simple suddenly became strangely complicated.

Then intense debates ensued and new proposals were made to define the planet. Brian Marsden, a member of the IAU executive committee responsible for finding a new meaning for the planet, told in 2005: “Every time we think some of us are reaching a consensus, then someone says something and shows that it’s clear.” It’s not like that.”

A year later, astronomers were still nowhere near a solution, and the dilemma hung over the IAU General Assembly in Prague in 2006 like a dark cloud. At this conference, the researchers had eight days of intensive discussion and presented four different proposals. A controversial proposal would have brought the total number of planets in the solar system to 12 by adding Ceres, the largest asteroid, and Pluto’s moon, Charon.

Michael Brown, an astronomer at Caltech University and discoverer of Eris, called the proposal “complete confusion.”

Planets and dwarf planets of the solar systemThe globular objects in the Kuiper Belt (right arrows) and Ceres (left arrow) are now called dwarf planets.

Near the end of the conference, the remaining 424 astronomers voted to create three new classifications for objects in the solar system. From then on, only Mercury and Neptune and the large worlds in between were considered planets. Then Pluto and its counterparts (round bodies that shared their orbits with other bodies) were called dwarf planets. All other objects that orbit the Sun are known as minor solar system bodies.

NASA’s New Horizons mission and the debate over the planet again

A group of experts did not take the decision of their colleagues seriously. Alan Stern, the senior researcher of NASA’s New Horizons spacecraft, which passed by Pluto in 2015, regretted the demotion of the former ninth planet of the solar system and said that less than five percent of the world’s 10,000 astronomers participated in the International Astronomical Union vote.

New Horizons was considered an important turning point in the planetary debate. The spacecraft’s quick flyby of Pluto revealed a world far more dynamic than anyone imagined. Large mountains, impact craters, and signs of liquid nitrogen flowing on the surface all suggest a world that has undergone significant geological changes since its formation. People like Stern have argued that Pluto should be considered a planet on that basis alone.

New Horizons was considered an important turning point in the planetary debate

Images taken from Pluto’s moon Charon also show a very dynamic place; Including the red cap on its pole, which apparently changes its appearance with the slow seasonal change in the solar system. Most importantly, Pluto has several moons; While Mercury and Venus, the two inner planets of the solar system, do not have even one moon. Many asteroids and dwarf planets also have moons, complicating the definition of a planet.

An artist's rendering of the New Horizons spacecraft over PlutoNew Horizons is the only spacecraft that has ever had a close encounter with Pluto.

Many people share views with Stern and other like-minded experts. In 2014, shortly before New Horizons flew past Pluto, experts at the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, debated different definitions of the planet. Owen Gingerich, a science historian who chairs the IAU’s Planet Definition Committee, stated that “planet is a culturally defined term that changes over time.” But most of the audience watching the CfA debate chose a different definition that would have put Pluto back among the planets.

Alternative classification schemes continue to be proposed. A 2017 proposal defined a planet as “a spherical body in space that is smaller than a star.” This definition makes Pluto a planet again; But it does the same with Earth’s moon, as well as many other moons in the solar system, bringing the total number of officially recognized planets to 110. A year later, Stern wrote an op-ed in The Washington Post with David Greenspoon, senior scientist at the Planetary Science Association, arguing that the International Astronomical Union’s definition was hastily adopted and problematic and that astronomers should rethink their ideas.

Can Pluto become a planet again?

Numerous requests from experts have so far been ignored, and the International Astronomical Union is unlikely to address the dispute anytime soon. “The simple fact is that Pluto was misclassified at the time of discovery,” wrote American astrophysicist Ethan Siegel in response to Stern and Greenspoon. “This crime has never been in the same position as the other eight worlds.”

Michael Brown also says: “As a result, Pluto is still not a planet, and in fact it never was.” We just got it wrong for 50 years and now we know better. Missing Pluto is not really a very good argument. “The reality is something else and we have to deal with it.”

What is the significance of Pluto being a planet?

The Sun and the planets of the solar system opposite Pluto

These days, children who weren’t even born when Pluto was a planet, ask what the definition of a planet even matters. Why do we have to discuss whether Pluto is a planet or not? Astronomers say there’s no simple answer, and we may have to look beyond our own solar system to understand what makes an object a planet or not.

More than five thousand exoplanets or worlds beyond the solar system have been discovered so far. This vast collection ranges from Earth-sized “super-Earths” to Uranus and “hot Jupiters” orbiting their star closely, to a range of worlds of other sizes. The types of planetary environments that must be considered are changing rapidly.

It seems unlikely that the International Astronomical Union will address the Pluto controversy anytime soon

What the increasing knowledge of the types of exoplanets shows us is that each star system may have its own unique environment. Although it can be more generally stated that stars can form planets from the collapse of gas and dust in their environment, the unique dynamics that control the process of planet formation are much more complex. For example, are multiple stars involved in this process? How much dust is there? Is there a black hole or supernova that will destroy the precious dust and gas needed to grow planets?

Even if planets are lucky enough to grow large, how they interact with other planets early in their formation is poorly understood. The worlds interact with each other, and the mutual gravitational effect between them causes the planets to move away from their parent star, close to it, or in some cases, fall out of the system altogether.

What all these explanations suggest is that our definition of a planet should probably be more contextual to account for the number of possible scenarios for the formation of worlds. Perhaps the planets depend on a specific formation condition or specific regions. All we seem to know for sure is that as more and more data is collected, the planet definition and the debate that Pluto has sparked will continue for some time to come.

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The planet Jupiter; Everything you need to know




Jupiter is the largest planet in the solar system and is highly regarded for its fascinating features such as the Great Red Spot and mysterious icy moons such as Europa and Ganymede.

The planet Jupiter; Features, moons, wonders, and everything you need to know

The planet Jupiter, known by other names such as Hormuz, Hormuz, or Jupiter, is the fifth and largest planet in the solar system. Jupiter has played a major role in the evolution of the history of the solar system and it can be said that the earth owes its survival to Jupiter.

This planet is one of the gas giants along with Saturn. The other two planets Uranus and Neptune are in the category of ice giants of the solar system. Jupiter is a mixture of hydrogen and helium, and due to its high rotation speed, its shape is not perfectly spherical. Jupiter’s outer atmosphere is divided into several bands with different latitudes, at the meeting points of these atmospheric bands, storms and eddy currents arise. One of the common points of these strips is the famous big red spot; A huge storm that was first observed with a telescope in the 17th century.

Jupiter has a faint ring and a strong magnetosphere. This planet, also called the king of planets, has 79 confirmed moons. In terms of the number of moons, Jupiter ranks second in the solar system after Saturn (with 82 moons). The most famous moons of this planet are a set of four known as the Galilean moons, which were discovered in 1610 by the Italian scientist Galileo Galilei. Ganymede is the largest moon of Jupiter and the largest moon in the entire solar system.

Robotic spacecraft have done a lot of research on Jupiter. Among the most famous Jupiter missions, we can mention the Voyager and Pioneer missions and then the Galileo orbiter. In late February 2007, the New Horizons probe visited Jupiter and used the planet’s gravity to increase its speed and get in the path of Pluto. The last mission to Jupiter was carried out by the Juno probe, which entered the orbit of the planet on July 4, 2016.

Table of Contents
  • Ten interesting facts about the planet Jupiter
  • What does the planet Jupiter symbolize?
  • How was Jupiter formed?
  • Disk instability model
  • Gravel accumulation
  • Customer relocation
  • Jupiter is how much bigger than Earth?
  • Physical characteristics and internal composition of the planet Jupiter
  • Jupiter’s atmosphere and cloud layers
  • Jupiter’s Great Red Spot
  • Jupiter’s magnetic field
  • Rotation and orbit of Jupiter
  • How many moons does Jupiter have?
  • group of moons
  • Irregular moons of Jupiter
  • Galilean moons
  • Moon Io
  • Callisto’s moon
  • Ganymede’s moon
  • Europa’s moon
  • Customer rings
  • Wonders of Jupiter
  • Seeing Jupiter from Earth
  • Pre-telescopic researches
  • Ground-based telescopic research
  • Radiotelescopic researches
  • Jupiter probes
  • Pioneer 10 and 11 (Pioneer)
  • Voyager 1 and 2
  • Galileo Spacecraft
  • Cassini spacecraft
  • Ulysses spacecraft
  • New Horizons spacecraft
  • Juno spacecraft
  • Images by James Webb of Jupiter
  • Future missions to the client
  • common questions

Ten interesting facts about the planet Jupiter

1. Jupiter is the largest planet in the solar system, which is named after the god of the sky and thunder. This planet is mainly composed of gas (hydrogen and helium) and its inner core is almost the same size as Earth.

2. The planet Jupiter has at least 79 moons, of which the four big red ones are: Io, Europa, Ganymede and Callisto (these moons are also known as Galilean moons in honor of Galileo). Although Jupiter cannot host life, some of its moons have the potential for life due to the existence of subsurface oceans.

3. Jupiter rotates around itself faster than any other planet, and this causes streaks: dark areas (belts) represent rising clouds and gases; Bright areas (areas) indicate belt subsidence.

4. Jupiter’s rotation speed is fast at the equator and slow at the poles; Thus, the gas layers in the impact areas cause white spots, spiral storms, and vortices. One of Jupiter’s most famous storms is the Great Red Spot, three times the size of Earth. This is not a permanent storm.

5. Jupiter has four rings. The Voyager 1 probe discovered these rings in 1979. These rings are very faint and were made of dust particles, unlike Saturn’s transparent rings, which are composed of ice and rock.

(from top to bottom): Jupiter’s Great Red Spot, Io, Europa, Ganymede, Callisto

During its mission, the Juno probe has also reached interesting facts about the planet Jupiter, which we mention:

6. Jupiter’s atmosphere is amazing. According to Juno’s findings, this gas giant is much more turbulent than expected. Cloudy and windy weather is not seen only in the upper layer of this planet. Rather, these winds exist thousands of kilometers deep in Jupiter. Also, surprisingly, Jupiter’s bands disappear near its poles.

7. According to the hypotheses, Jupiter’s famous gas clouds (a mixture of water and ammonia) are equally mixed. However, there is less ammonia on the surface and more ammonia is concentrated in the core.

8. At Jupiter’s north and south poles, circular chains of massive tornadoes are flowing. These rotating storms are very dense in the dimensions of the continents of the earth. Their length reaches 48 kilometers and their width reaches hundreds of kilometers.

9. Jupiter’s solid core is not fully compressed at its center. Rather, it is an inflated sphere in the dimensions of half the diameter of Jupiter. No one knows what is the reason for this problem, but according to the hypotheses, a heavy mass collided with Jupiter, which caused its core to combine with other surrounding gases.

10. Jupiter has the strongest magnetic field in the Solar System, but Juno shows it’s even stronger than expected, closer to the planet’s surface. Also, Jupiter’s north and south poles are not the same.

What does the planet Jupiter symbolize?

The planet Jupiter has been known since ancient times. This planet is also known by many names in different cultures such as Jupiter (Roman culture), Burgess, Urmazd, and Zavash. Jupiter can be seen in the night sky with the naked eye and sometimes during the day (when the sunlight is low). The Romans named this planet after one of the gods of Roman mythology, Jupiter (also known as the god of love).

The Babylonians knew Jupiter by the name of their god, Marduk. They used Jupiter’s 12-year period next to the ecliptic to define the zodiac constellations. The Romans considered Jupiter a star. On the other hand, in Greece, Jupiter was known as Zeus (the equivalent of the Roman god Jupiter). The ancient Greeks knew this planet as Phaeton, which means shining or burning star. The origin of the astrological symbol of Jupiter (image below) is not known, But many consider it to be a symbol of lightning, and according to new reports, this symbol is based on the Egyptian hieroglyphic script that means eagle.

It has been nearly 13.8 billion years since the Big Bang and the beginning of the universe, and almost 4.6 billion years since the formation of the solar system. Jupiter is the oldest planet in the solar system. This planet, which is 2.5 times heavier than the rest of the planets in the solar system, has played an important role in the formation and evolution of its neighbors. 4.6 billion years ago, the solar system was a cloud of gas and dust or the solar nebula. Gravity caused this material to collapse and begin to rotate; The sun was born in its center. As the sun formed, the rest of the material condensed. Small particles were brought close to each other by the force of gravity and turned into larger particles.

The solar wind blew away lighter elements like hydrogen and helium, and heavier rocky material near the Sun formed smaller rocky worlds like Earth. Since the solar wind had less effect on the lighter elements, these elements joined together to form gas giants.

According to the core accretion model, the rocky cores of the planets were formed first, then the lighter elements formed the mantle and the crust of the planets. On rocky worlds, the lighter elements formed the atmosphere. Examination of exoplanets (outside the solar system) supports the core accretion theory as the dominant formation process. Stars with more metal in their cores (a term astronomers use for elements other than hydrogen and helium) have larger planets in their systems than stars made only of metal.

The core accretion process for gas giants like Jupiter takes a long time. The cloud of matter around the sun lasts only a short time; It either becomes a planet or disappears completely. Giant planets, unlike rocky planets such as Mars and Earth, formed very quickly and only in a few million years. As a result, based on a certain period of time, the gas ring around the sun lasted only 4 to 5 million years.

According to a relatively new theory called disc instability, masses of gas and dust joined together early in the life of the solar system. Over time, these masses turned into larger planets. The speed of formation of these planets based on this theory is faster than the core accumulation theory and sometimes even reaches several thousand years. Constant collisions in Jupiter (just like other planets) raised the temperature of this planet. Dense material moved towards the center and formed the nucleus. Some scientists believe that the core of this planet can be a hot ball of liquid; While according to other researchers, Jupiter’s core is a solid rock with a size of 14 to 18 times that of Earth.

Gravel accumulation

The biggest challenge of nuclear accretion theory is its time. According to another study, small pebble-sized objects joined together to form large planets at a rate 1,000 times faster than previous models. In 2012, two researchers named Michel Lambrecht and Anders Johansen from Lund University in Sweden presented the theory of small particles. Based on their analysis, pebbles left over from formation processes (which were previously considered insignificant) could hold the key to the problem of planet formation.

Customer relocation

In 2011, scientists unveiled the Grand Tack model. According to this theory, the customer had a two-stage migration after forming. Jupiter was formed exactly at a distance of 3.5 AU from the Sun, and after a two-stage transition, it is at its current position of 5.2 AU.

Jupiter is thought to have destroyed many objects during these transits, including some of the first-generation planets of the solar system. Without Jupiter, there would probably be no Earth; This planet has cleared the way for Earth by destroying smaller worlds.

Jupiter is how much bigger than Earth?

If we add the mass of all the planets of the solar system together, the mass of Jupiter will be more than twice that. This gas giant can accommodate 1300 planets. As a result, if you consider the planet Jupiter to be the size of a basketball, the Earth will be the size of a grape seed. This gas planet is also 318 times heavier than Earth. In the diameter of Jupiter, you can fit 11 planets.

Planet Earth against Jupiter; Jupiter contains more than 1300 lands

Physical characteristics and internal composition of the planet Jupiter

A large part of Jupiter consists of liquid and gaseous materials. The diameter of this gas giant reaches 142,984 km. Its average density is 1326 grams per cubic centimeter, and in this respect, it ranks second among gas giants. A large part of Jupiter consists of gaseous and liquid materials, and denser materials are located in the lower layer. 88-92% of the upper atmosphere of this planet is made up of hydrogen and 8-12% of it is made up of helium. Generally, 75% of the mass of this planet is hydrogen, 24% is helium and the remaining 1% are other elements.

Jupiter’s atmosphere contains amounts of methane, water, steam, ammonia, and silicon compounds. Traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur can also be seen in it. The outermost layer of the atmosphere consists of frozen crystals of ammonia. The material density is higher in the inner layers. The discovery of water on the planet Jupiter was one of the interesting discoveries of the past years. Using the Juno probe, scientists have found evidence of water on the planet Jupiter, which is far beyond their imagination.

Using ultraviolet and infrared measurements, amounts of benzene and hydrocarbons have also been discovered on this planet. According to the spectroscopic results, the composition of Jupiter is almost the same as that of Saturn; But the other two gas giants, Uranus and Neptune, have less hydrogen and helium and more ice than Jupiter, and hence they are also called ice giants.

Jupiter can hold 1,300 Earths

Based on gravity measurements in 1977, the mass of the core of this planet was estimated to be 12 to 45 times greater than the mass of Earth. Jupiter’s core makes up 4-14% of its total mass. The radius of Jupiter is approximately one-tenth of the radius of the Sun and the mass is one-thousandth of the mass of the Sun; Therefore, the density of both is the same. Jupiter’s mass is commonly used as a unit to describe the mass of other objects, especially exoplanets or brown dwarfs.

If Jupiter were 75 times heavier, it would have the possibility of hydrogen fusion and become a star; Meanwhile, the radius of the smallest red dwarf is only 3% more than Jupiter. However, Jupiter emits more heat than it receives from the sun.

The amount of heat produced by Jupiter is equal to the total solar radiation received by this planet. This process causes Jupiter to become smaller by 2 cm every year. While it was much hotter at the beginning of its formation its diameter was twice its current diameter. According to existing hypotheses, the core of Jupiter is rocky; But its exact composition is still unknown. The core may be surrounded by dense metallic hydrogen, which makes up 78% of the planet’s radius. Raindrops such as helium and neon are deposited towards the bottom of this layer and the abundance of these elements in the upper atmosphere is minimized.

Customer core
This cut shows a model of Jupiter’s interior with a rocky core surrounded by a deep layer of liquid metallic hydrogen.

Like the Sun’s atmosphere, most of Jupiter’s atmosphere consists of hydrogen and helium. The dark and light-colored bands on Jupiter’s atmosphere are caused by strong east-west winds that move at a speed of more than 539 kilometers per hour. Clouds in bright areas are composed of frozen crystals of ammonia; While clouds in darker areas are made up of other chemicals. In the deepest observable level of this planet, there are blue clouds. Jupiter’s cloud bands change over time and rain diamonds within Jupiter’s atmosphere.

It is hard to say what exactly Jupiter’s atmosphere is made of because 90% of this planet is hydrogen and 10% is helium. On Earth, all these gases are considered atmospheric; But the strong gravity of Jupiter causes the atmosphere of this planet to become several separate layers, each of which has attractive and unique characteristics. Unlike Earth, there is no clear boundary between Jupiter’s atmosphere and the planet itself. By penetrating further into the depths of Jupiter, the density and temperature of hydrogen and helium change, and based on these changes, scientists describe the different layers of Jupiter’s atmosphere. Jupiter’s atmospheric layers include the troposphere, stratosphere, thermosphere, and exosphere.

Since Jupiter does not have a solid surface, scientists estimate the pressure of the lower part of its atmosphere to be 100 kilopascals; The planet’s atmosphere is defined just above this point. Like Earth’s, Jupiter’s atmosphere decreases with altitude until it reaches its minimum value. The minimum amount of atmosphere can be found at the boundary between the troposphere and stratosphere, the tropopause (approximately 50 km above the surface of Jupiter).

The stratosphere extends up to a height of 320 km, and along that line, the pressure decreases, as the pressure decreases, the temperature increases. At this point, the boundary between the stratosphere and the thermosphere is defined. The temperature of the thermosphere reaches 726 degrees Celsius at an altitude of 1000 kilometers. All visible clouds and storms are located in the lower troposphere of Jupiter and are composed of ammonia, hydrogen sulfide, and water.

Jupiter’s Great Red Spot

The most obvious feature of Jupiter is its big red spot. This spot is a persistent larger-than-Earth cyclonic storm located at an angle of 22 degrees to the equator, which was discovered based on one hypothesis from 1831 and another from 1665. This spot is large enough to be easily seen with an amateur telescope with an aperture of 12 cm. The rotation direction of this tornado is anti-clockwise and its circulation period is 6 days. The maximum height of this storm is 8 km above the cloud area.

According to mathematical models, this storm is stable and may be one of the stable features of this planet. However, the size of this spot has always decreased. In the late 1800s, the width of this spot was estimated to be about 56,327 km, which is four times the diameter of the earth. After the Voyager 2 spacecraft reached this planet in 1979, the diameter of this storm had decreased to twice the width of the planet Earth.

Reviews of Jupiter’s red spot show that the spot is still shrinking in size. On April 3, 2017, the width of this spot was estimated to be 16,350 km, which is 1.3 times the diameter of the Earth. Earth’s longest storm lasts 31 days, But Jupiter has more stable storms due to having thousands of kilometers of atmosphere at a speed much faster than the Earth’s rotation.

red spot
Jupiter’s Great Red Spot has shrunk over the years.

Jupiter’s magnetic field

Jupiter’s magnetic field is fourteen times stronger than Earth’s magnetic field. This field is thought to be created by eddy currents in the metallic hydrogen core of this planet. Some features of Jupiter’s magnetic field are unique and do not exist in Earth’s magnetic field.

The volcanoes of Jupiter’s moon Ivy release large amounts of sulfur dioxide, resulting in a gas halo around the moon’s orbit. This gas is ionized in Jupiter’s magnetosphere and sulfur and oxygen ions are released.

These ions together with the hydrogen ion of Jupiter’s atmosphere form a plasma sheet in the equatorial body of this planet. The plasma in this sheet rotates with the planet and leads to the change of the bipolar magnetic field into a magnetic disk. The electrons in the plasma sheet create a strong radio effect that produces bursts in the 0.6 to 30 MHz range.

Jupiter’s magnetosphere is responsible for the intense emission of radio material from the polar regions of this planet. Volcanic activities of this planet’s moon Ivy lead to the release of gas in Jupiter’s magnetosphere and create a halo of particles around it. As Io moves in this halo, Alphon waves are created. An Alfón wave is a type of magnetohydrodynamic wave in which ions oscillate along magnetic field lines in response to an effective voltage. These waves carry ionic material in Jupiter’s polar regions.

Rotation and orbit of Jupiter

The average distance between Jupiter and the Sun is 778 million kilometers (about 5.2 times greater than the distance between the Earth and the Sun) and the Earth orbits the Sun every 11.86 years. Compared to Earth, Jupiter’s elliptical orbit has a deviation of 1.31 degrees. The eccentricity of this planet’s orbit is 0.048, which is why its distance from the Sun varies between the closest contact (perigee) and the farthest distance (apex) as much as 75 million kilometers.

The axial tilt of this planet is relatively small: 3.13 degrees. As a result, it does not have many seasonal changes compared to Earth and Mars. Jupiter rotates the fastest among the planets of the solar system and completes its rotation around its axis in less than ten hours. Due to the high speed of rotation, an equatorial bulge is created, which is easily visible through an amateur telescope located on Earth. The diameter of Jupiter’s equator is 9275 km more than the diameter of its poles. Because Jupiter is not a solid body, its upper atmosphere has a different rotation. Jupiter’s polar atmosphere rotates approximately 5 minutes longer than its equatorial atmosphere.

How many moons does Jupiter have?

Jupiter has 79 confirmed moons. In terms of the number of moons, Jupiter ranks second in the solar system after Saturn (with 82 moons); But according to the latest research, Canadian astronomers found evidence of the existence of 45 small moons in the orbit of Jupiter, and based on speculations, the number of moons of this planet can reach 600; But they have not yet reached the verification and monitoring stage.

Overall, among Jupiter’s 79 confirmed moons, the four largest Galilean moons are the most prominent. These moons were discovered independently by Galileo Galilei and Simon Marinus in 1610. As early as 1892, more moons of Jupiter were discovered and named after the lovers or daughters of Jupiter, the Roman god, or Zeus (his Greek counterpart). The Galilean moons are the largest and heaviest objects in Jupiter’s orbit.

Jupiter’s eight moons are regular moons with nearly circular orbits. The Galilean moons are nearly spherical due to their planetary mass. If these moons were in the orbit of the sun, they would be classified as dwarf planets. The other four moons are smaller and less distant from Jupiter; These moons are sources for the formation of Jupiter’s rings. Other moons of Jupiter are irregular and their orbits are further away from Jupiter. These moons are probably trapped by Jupiter’s gravity from the solar orbits. Jupiter’s twenty-two irregular moons have yet to be officially named.

Jupiter’s regular moons are thought to have formed from the planet’s rotating disk; A ring of gas and rock similar to a primordial planetary disk. On the other hand, irregular moons are composed of asteroids that are caught in the trap of Jupiter’s gravity. According to many scientists, these asteroids were crushed and then formed the irregular moons of Jupiter due to impact with other small bodies.

Group of moons

In general, Jupiter’s moons are divided into two categories: regular and irregular. Irregular moons are divided into two groups: internal moons (Amaltia) and Galilean moons.

  • Internal moons (Amaltia): Metis, Adrastia, Amaltia, and Thebe are internal moons of Jupiter; Because they are in close proximity to this planet. Two of the innermost moons complete the orbit of Jupiter in less than a day. The other two moons are the fifth and seventh largest moons in Jupiter’s lunar system, respectively. According to observations, at least the largest member of this group, Amaltia, did not form on the current orbit, but was already further away from Jupiter.
  • The main group of Galilean moons: Io, Europa, Ganymede, and Callisto are among the largest moons in the solar system in terms of mass and size. The diameter of the moon Ganymede is even greater than the planet Mercury, but its mass is less. These moons are the fourth (Io), sixth (Europa), first (Ganymede), and third (Callisto) natural moons of the solar system, respectively, and comprise approximately 99.997% of the total mass of Jupiter’s orbit. Jupiter is 5000 times heavier than its moons.

Irregular moons of Jupiter

Irregular moons of Jupiter are small bodies with eccentric orbits and further away from Jupiter. These moons have similarities such as declination, eccentricity, semimajor axis, and chemical composition. According to scientists, these are a group of impact moons that were formed by the collision of larger parent objects with asteroids caught in Jupiter’s gravitational field.

Galilean moons

The Galilean moons are among the most well-known moons of Jupiter that have been studied by various probes and more information is available. In the following, we mention the features and explorations related to these moons.

Moon Io

Io is the fifth largest moon of Jupiter and has the most volcanic activity in the solar system. This moon has sulfur channels that spread up to 300 km. Io’s surface is filled with lava seas and liquid rock floodplains. Astronomers discovered a map of 150 volcanoes on this moon, some of which emit lava up to 400 kilometers into space. At 4.5 billion years old, Io is the same age as its host planet Jupiter. The average orbital distance between Io and Jupiter is 442 thousand km. It takes 1.77 Earth days for Io to complete an orbit around Jupiter. Io has a tidal lock and always has one side facing Jupiter. The diameter of Io is approximately 1,820 km, which is slightly more than the diameter of the Moon.

Io is the only moon in the solar system with active volcanoes

Io has a relatively oval shape. Among the Galilean moons, Io ranks lower than Ganymede and Callisto in terms of mass and volume and ranks higher than Europa. The average surface temperature of Io is minus 130 degrees Celsius. For this reason, sulfur dioxide snow bodies are abundant on its surface. Io is also called the moon of ice and fire.

Io was discovered on January 8, 1610, by Galileo Galilei. He actually discovered this moon the day before, But he could not distinguish Io ​​and Europa. Galileo’s discovery was the first lunar discovery at that time. Galileo’s discoveries proved that the planets revolve around the sun, not the earth. Galileo initially named this moon Jupiter 1; But in the middle of the 19th century, its name was changed to Ayo. In Greek mythology, Io was the priestess of Hera (wife of Zeus) and the daughter of Inachus, king of Argos. Zeus (the Greek counterpart of the Roman god Jupiter) fell in love with Io, But he turned him into a cow to protect him from his wife Hera.

IO features: IO’s interior consists of an iron sulfide core and a brown silicate outer layer. This combination has given this moon a mottled appearance with orange, black, yellow, red, and white colors. Based on data obtained from computer models, Io formed in a region around Jupiter where the abundance of ice was initially high. The heat of Io along with the water on its surface shortly after its formation can be a sign of the existence of ancient life; Even in an environment where Jupiter’s radiation destroys surface water.

The most prominent features of this moon are its volcanoes. After Earth, Io is the only body in the solar system with active volcanoes. Galileo made notes of volcanic activity, and NASA’s Voyager spacecraft confirmed Io’s volcanoes in 1979. Due to volcanic activity, a large part of the atmosphere is sulfur dioxide. Based on observations from the Gemini North telescope in Hawaii and the TEXES spectrometer in 2018, Io’s atmosphere is likely to collapse. Io’s sulfur dioxide gas mantle freezes in shadow every day. When Io returns to sunlight, the frozen sulfur dioxide turns into a gas once more.

Moon Io

Callisto is one of the large moons in the orbit of Jupiter. This moon has an ancient surface full of impact craters, which shows that there is no news of geological processes in it; But this moon has an underground ocean and because of its old surface, the existence of life in this ocean is still not certain.

Callisto, like the other four Galilean moons, was discovered in 1610. The name of this moon was originally Jupiter IV, But in the 19th century, it was called Callisto. Callisto was studied by several probes, including the long-duration mission of the Galileo spacecraft to Jupiter in the 1990s and 2000s. The Juno spacecraft has also recorded remote images of the moon Callisto. At 4.5 billion years, Callisto is the same age as its host planet, Jupiter. This moon is the heaviest body with an impact hole in the entire solar system, But its surface has remained untouched since almost 4 billion years ago.

Among the Galilean moons, Callisto is the outermost. This moon is located at a distance of one million eight hundred and eighty thousand kilometers from Jupiter. Callisto takes approximately seven Earth days to complete an orbit of Jupiter. Callisto has fewer tidal effects than the other Galilean moons; Because on the other side of Jupiter’s main radiation belt is located. Callisto is tidally locked to Jupiter and always faces Jupiter on one side.

With a diameter of 4800 km, Callisto is almost the same size as the planet Mercury. This moon is the third largest moon in the solar system after Ganymede and Titan (Saturn’s moon). Moon is placed in fifth place after Io. Callisto’s surface temperature reaches minus 139.2 degrees Celsius. In 1996, the Galileo spacecraft sent back detailed information about Callisto. The mission mapped much of the moon’s surface and discovered its thin carbon dioxide atmosphere and evidence of a subsurface ocean. Callisto’s effect on the auroral bursts of Jupiter’s atmosphere has been revealed based on a review of images obtained from the Hubble Space Telescope in 2018. The client himself has an aura, But some of Jupiter’s aurora phenomena originate from interactions with its four large moons.

Future missions, including JUICE, which will investigate Jupiter’s icy moons, will reveal more about Callisto and the possibility of life there. Papers have also been published on modeling the interaction of Jupiter’s magnetic field with Callisto (this review provides evidence for Callisto’s subsurface ocean) and finding atomic oxygen in the moon’s atmosphere. Other papers have focused on dimensions such as subsurface water, the number of impact craters, and atmospheric properties.

Callisto's moon

Ganymede is the largest moon of Jupiter and the largest moon in the entire solar system. This moon is even bigger than Mercury and Pluto and slightly smaller than Mars; As a result, if it was in the orbit of the sun, it would easily be classified as a planet. Ganymede probably has a saltwater ocean beneath its icy surface; As a result, it becomes one of the strong candidates for life discoveries. Ganymede is one of the targets of the JUICE mission, which will be launched in the 2030s.

The three moons of Callisto, Ganymede, and Europa have subsurface oceans of saltwater

Like Callisto and Io, Ganymede is the same age as Jupiter at 4.5 billion years old. This moon is more than one million and seventy thousand kilometers away from Jupiter and completes the orbit of this planet in seven days. The average radius of Ganymede is 2631.2 km. Ganymede is larger than Mercury, but its mass is half that of Mercury, and as a result, it has a low density. The average daytime temperature on the surface of Ganymede reaches minus 113 to minus 183 degrees Celsius. Astronomers with the Hubble telescope found evidence of Ganymede’s thin oxygen atmosphere in 1996. However, this atmosphere is too thin to support life as we know it, and it is unlikely that life could inhabit Ganymede.

Ganymede is the only moon with a magnetosphere in the entire solar system. A magnetosphere, commonly seen on planets like Jupiter and Earth, is a comet-shaped region where charged particles are trapped and deflected. Ganymede’s magnetosphere is embedded in Jupiter’s magnetosphere. After Galileo discovered Ganymede, he renamed it Jupiter III. With the increase in the number of objects discovered in the middle of the 19th century, the name of this moon was changed to Ganymede based on Greek mythology.

Features of Ganymede: Ganymede has an iron core, a rocky mantle, and a very thick crust, most of which is made up of ice. Also, traces of rock formation can be seen on the surface of Ganymede. In February 2014, NASA unveiled a detailed map of Ganymede in the form of images and video animation, created using observations from NASA’s Voyager 1 and 2 spacecraft as well as the Galileo orbiter.

Ganymede’s surface consists of two main surface types: approximately 40% of Ganymede’s surface is dark with numerous impact craters, and 60% is light-colored with grooves that give Ganymede its distinctive appearance. Grooves are caused by tectonic activities or subsurface water release.

According to scientists, Ganymede has an underground saltwater ocean. In 2015, scientists used the Hubble Space Telescope to study Ganymede’s auroras and the changes between the magnetic fields of Jupiter and Ganymede. Based on the evidence of these auroras, Ganymede probably has a subsurface ocean of saltwater that is even saltier than Earth’s oceans.

Some scientists have pointed to the possibility of life on Ganymede. Because of Ganymede’s internal structure, the pressure on the ocean floor is so high that any water that reaches it turns into ice. For this reason, hot water currents can hardly deliver nutrients to the oceans.


Europa is the smallest Galilean moon. The surface of this moon is frozen and covered with a layer of ice; But according to scientists, there is an ocean under this ice surface. The icy surface makes Europa one of the most reflective moons in the solar system.

Using the Hubble Space Telescope, researchers detected signs of geysers from the Antarctic region of Europe in 2012. After several attempts, another research team observed the geysers in 2014 and 2016. Europa’s moon formed at the same time as its host planet, Jupiter, about 4.5 billion years ago. On average, the distance between Europe and Jupiter is 670,900 kilometers. It takes Europa three and a half Earth days to complete an orbit of Jupiter. Europe has a tidal lock to Jupiter; Therefore, one side is always facing the customer.

With a diameter of 3100 km, Europa is smaller than the Moon and larger than Pluto. The temperature of Europe’s surface at the equator never rises above minus 160 degrees Celsius, and at the poles of this moon, it never rises above minus 220 degrees Celsius. Galileo discovered the Europa moon on January 8, 1610. Of course, he had observed it the day before on January 7; But he could not distinguish this moon from Io. In Greek mythology, Europa is stolen by Zeus (a counterpart of Jupiter, the Roman god) and takes the form of a white bull to seduce Europa. He decorates the cow with flowers and sends it to the city of Crete. Zeus returns to his normal form in Crete and seduces Europa. Europa was the queen of Crete and bore Zeus several children.

One of the prominent features of Europa is its high reflectivity due to its ice crust. According to scientists’ estimates, the surface of Europe is 20-180 million years old. Images and data from the Galileo spacecraft show that Europa has a composition of silicate rock, an iron core, and a rocky mantle just like Earth. Unlike the Earth’s interior, Europa’s rocky atmosphere is surrounded by a layer of water or ice, which is 80 to 170 km thick. Based on the fluctuations of Europa’s magnetic field, there is probably an ocean beneath the moon’s surface that could host life. The possibility of extraterrestrial life has made Europa an attractive destination for space exploration.

The surface of Europe is full of cracks and fissures. According to many scientists, these cracks are the result of the tidal forces of the ocean beneath Europa’s surface. As Europa approaches Jupiter, sea levels below the ice rise above normal. In this situation, the continuous tide of the sea causes cracks in the surface of this moon. In 2014, scientists discovered that Europa could host tectonic plates. In the solar system, only the Earth has a variable crust, which is useful for the evolution of life on Earth.

Life in Europa: The presence of water under the frozen crust has made Europa’s moon one of the possible candidates for hosting life in the solar system. The icy depths of this moon probably have channels to the mantle like Earth. These channels provide the warm environment necessary for the evolution of life. According to a 2016 study, Europa’s oxygen content was estimated to be ten times that of hydrogen, similar to that of Earth. Thus, the ocean under the surface of Europe becomes a better environment for life.

Europa's moon
Europa, a moon of Jupiter

Customer rings

Maybe for many people this question has arisen, why the planet Jupiter does not have rings like Saturn? In fact, Jupiter has rings, but since Jupiter’s rings are made of rock and dust, and Saturn’s rings are made of rock and ice, Jupiter’s rings do not appear as bright as Saturn’s rings. Jupiter’s rings are divided into three parts: halo, main ring, and thin ring. Jupiter’s rings were discovered by the Voyager probe in 1980. The composition of Jupiter’s rings is different from that of Saturn, which is composed of ice. Jupiter’s rings are very faint and delicate.

  • Halo section: The innermost part of Jupiter’s rings, which is made up of dust and surrounds the space around the planet. This is the brightest and thickest part of Jupiter’s rings.
  • The main ring section: The main ring section is the narrowest part and consists of dust and gravel. The age of dust particles in this section reaches 1000 years or even 100 years. This means new dust is formed due to impact with larger rocks.
  • Thin Outer Ring (Gossamer): Gossamer is the outermost part of Jupiter’s rings. This part, like the previous two parts, is a combination of dust particles; But the word Gossamer means thin material, which is suitable for this part because of the very small dust particles.

Only the most powerful telescopes are capable of observing Jupiter’s rings. Jupiter’s moons are responsible for the formation of the rings of this planet. The innermost moons, such as Amaltha, Adrasta, and Tibe, were hit by many meteorites, and their dust and rock particles entered Jupiter’s orbit, thus forming the rings of this planet.

Wonders of Jupiter

The planet Jupiter has many surprises due to its strong gravity and magnetic field, as well as its strange moons. Below are some examples of these surprises:

The effect of Jupiter on the solar system: Jupiter is also known as the vacuum cleaner of the solar system due to its strong gravity and internal position of the solar system. This planet experienced the most collisions with comets among the planets of the solar system and thus it is thought to act as a shield for the inner planets of the solar system.

If Shoemaker’s comet Levi 9 collided with Earth, there would be no trace of life left on Earth.

However, based on recent computer simulations, Jupiter has not played a significant role in reducing the bombardment of the inner planets of the solar system, although the debate on this issue is still ongoing. At least it saved the inner planets from a catastrophe called Shoemaker Levi 9. Comet Shoemaker Levi 9 has experienced one of the most exciting endings. Shoemaker Levy’s collision with Jupiter left scars on the planet’s surface that are visible even from Earth. This is the first collision of two internal bodies in the solar system, and the effects of this comet on Jupiter’s atmosphere are spectacular and beyond expectations.

Shoemaker’s comet Levi 9 collided with Jupiter in 1994, and this collision caused a lot of fear among the public because if a similar comet hit the Earth, life on the planet would be completely destroyed.

Effects of comet Shoemaker Levi 9 impact on Jupiter

Two movies, Armageddon and Deep Encounter, were inspired by this encounter and were made with the theme of Earth-threatening objects. After the release of these videos, Congress asked NASA to search for near-Earth objects. Shoemaker Levi 9 was first discovered in March 1993 by comet explorers Eugene and Carolyn Shoemaker and David Levi. The group had previously collaborated several times and discovered other comets. For this reason, the name Shoemaker Levi 9 was chosen for this comet.

This comet had been orbiting Jupiter decades before, in 1966, but it had not been trapped by the planet’s strong gravity. Orbital calculations further indicated that this comet collided with Jupiter in July 1994. At that time, the Galileo spacecraft was still en route to the planet and could not capture a close-up view of the encounter.

Strange auroras: This year, the Juno probe discovered new auroras that oscillate over Jupiter’s poles. Juno’s Ultraviolet Spectrometer (UVS) instrument recorded this bright phenomenon. These auroras expand in the form of rings with a high speed between 3.3 and 7.7 km/s. According to scientists, these auroras are caused by charged particles from the edge of Jupiter’s huge magnetosphere. Jupiter’s auroras, like Earth’s, depend on the charged particles of the magnetosphere. However, Jupiter’s magnetosphere is 2000 times stronger than Earth’s magnetosphere.

Hubble telescope image of Jupiter’s auroras

New facts about Jupiter’s hot spots: A generation after discovering Jupiter’s hot, dense atmosphere, the Juno mission has new answers about these spots. Juno discovered hot spots that were much wider and deeper than past models and observations. These results were announced on December 11, 2020, at the annual conference of the American Geophysical Union.

More water discovered in Jupiter’s atmosphere: According to data from the 2020 Juno probe, approximately 0.25 percent of the molecules in Jupiter’s equatorial atmosphere are water molecules. Although this amount does not seem much, based on the calculations of water components, hydrogen and oxygen in Jupiter are three times more than the water molecules of the Sun. Juno’s measurements discovered more water than previous missions. This discovery could help scientists in their search for the true origin of Jupiter.

The similarity of Jupiter’s wavy atmosphere to Earth’s clouds: Jupiter and Earth may seem like two completely different planets, but the atmospheres of these two planets are more similar than they seem. In 2018, the Juno probe captured images of small-scale wave patterns in Jupiter’s atmosphere. These images, captured by the JunoCam instrument, reveal the similarity of these cloud shapes to Earth. These waves in the Earth’s atmosphere are called mesoscale or medium-scale waves. Now, similar waves have been discovered in Jupiter’s atmosphere, which are called atmospheric waves.

In this image taken by NASA’s Juno spacecraft, the shape of Jupiter’s atmospheric clouds resembles a tornado on Earth.

Seeing Jupiter from Earth

Jupiter is the fourth brightest object in the night sky (after the Sun, Moon, and Venus). Depending on Jupiter’s position relative to the sun and the Earth, its range of vision varies. The average visibility range of this planet is minus 2.20 and its standard deviation is 0.33.

Since the orbit of Jupiter is outside the Earth, the phase angle of this planet from the Earth never exceeds 11.5 degrees. For this reason, this planet is always seen brightly from telescopes on the ground. With a small telescope, you can even observe the Galilean moon and the cloud belts around Jupiter’s atmosphere.

Pre-telescopic researches

Jupiter’s observation dates back to Babylonian astronomers in the 7th or 8th century BC. Chinese astronomers also observed the orbit of Jupiter and based on the approximate number of years, they made its 12-branched terrestrial cycle. Ground-based telescopic research

In January 1610, Galileo Galilei examined the planet Jupiter with his small telescope. His observations changed the current understanding of the universe. Galileo observed three small stars near Jupiter. The next afternoon, he was able to see the stars again, but this time they were on the other side of the planet. Over the course of several weeks of observation, these stars moved around Jupiter. Galileo gave the name of Medici’s stars to these objects out of gratitude to his patron Cosmo de’ Medici, but today they are known as Galileo’s moons.

This observation was the first telescopic observation of the moons of the solar system (other than the Earth’s moon). A day after Galileo, Simon Marinus independently discovered the moons around Jupiter, but he did not publish the results of his discoveries until 1614. This discovery was a turning point in Copernicus’ heliocentric theory of planetary motion. Galileo was prosecuted for blasphemy for supporting this theory.

Giovanni Cassini
Giovanni Cassini

In the 1660s, Giovanni Cassini used a new telescope to discover Jupiter’s colorful bands and spots and was able to estimate the planet’s rotation period. In 1690, Cassini realized the difference between the rotation of Jupiter’s atmosphere and the planet itself. Probably, the Great Red Spot in the southern hemisphere of Jupiter was observed in 1664 by Robert Hooke and in 1665 by Cassini, although there is still a debate on this issue. Astronomer Henrich Schwab published the first detailed sketch of the Great Red Spot in 1831.

Both Giovanni Beverley and Cassini made detailed tables of Jupiter’s lunar motions, and based on that, they used to predict the motions of these moons. In 1892, E.E. Barnard discovered the fifth moon of Jupiter at Lake California Observatory. The discovery of this relatively small object made him famous. This moon was named Amalatha. It was the last planetary moon to be discovered directly by visual observation.

In 1932, Robert Wildt discovered the bands of ammonia and methane. Three gyres (large-scale rotation of wind around a central point of high atmospheric pressure counterclockwise) called white rings were also discovered in 1938. Finally, two rings were merged in 1998 and the third ring known as BA was absorbed in 2000.

Radiotelescopic researches

In 1955, Bernard Burke and Kenneth Franklin managed to detect bursts with a power of 22.2 MHz based on radio signals. The period of these bursts coincided with the rotation of the planet, and they used this information to correct the rotation ratio. Jupiter’s radio bursts come in two main forms: long bursts (L bursts) lasting up to several seconds, and short bursts (S bursts) lasting less than a hundredth of a second.

Jupiter probes

So far, eight spacecraft and probes have explored Jupiter: Pioneer 10 and 11, Voyager 1 and 2, Galileo, Cassini, Ulysses, New Horizons, and Juno.

Pioneer 10 and 11 (Pioneer)

Pioneer 10 and 11 were the first spacecraft to explore Jupiter. These two probes recorded the first scientific observations of Jupiter and Saturn, paving the way for the Voyager missions. The external instruments of these spacecraft investigated the atmospheres of Jupiter and Saturn, magnetic fields, moons, and rings, as well as interplanetary dust and magnetic regions, solar winds, and cosmic rays. These two probes continued their journey and left the solar system.

Pioneer 10
Picture of Pioneer 10 from Jupiter

Voyager 1 and 2

NASA sent two Voyager spacecraft to Jupiter, Saturn, Uranus, and Neptune in the late summer of 1977. Voyager 1’s closest contact with Jupiter was recorded on March 5, 1979. Voyager 2’s closest approach to this planet was recorded on July 9, 1979.

Jupiter photography began in January 1979. Voyager 1 completed its mission to Jupiter in early April after recording 19,000 images and many other science measurements. Voyager’s mission period was from late April to early August. The two spacecraft captured more than 33,000 images of Jupiter and its five moons. Voyager 1 and 2 provided researchers with a lot of information about moons, magnetic fields, and more. The biggest achievement of these two spacecraft was the discovery of active volcanoes on Io’s moon.

Voyager 1 image of Jupiter

Galileo Spacecraft

The Galileo spacecraft was launched on October 18, 1989, by the space shuttle Atlantis and reached Jupiter in 1995. This probe spent almost eight years in the orbit of Jupiter and studied its moons. Based on the information obtained from the camera and nine other instruments of this probe, the possibility of an ocean under the surface of Europa’s moon was investigated. According to the discoveries, the volcanoes of Io’s moon are very active. One of Galileo’s other discoveries was the distinct magnetic field of Ganymede. Galileo was carrying a small probe that was sent deep into Jupiter’s atmosphere, and about an hour later it was destroyed by high pressure.

Cassini spacecraft

Cassini was a joint collaboration between NASA the European Space Agency (ESA) and the Italian Space Agency, and its main objective was to study Saturn, its ring system, and its moons. The probe made its closest approach to Jupiter on December 30, 2000, and recorded numerous scientific measurements. Cassini captured 26,000 images of the planet, its rings, and moons during its six-month flyby around Jupiter. Cassini’s greatest achievement of Jupiter was capturing the most detailed color portrait of the planet (up to that time).

Among other Cassini observations, we can mention a dark swirling cloud in the upper part of Jupiter’s atmosphere, which was almost the same size as the Great Red Spot and is located near its north pole. Based on the evidence that Cassini obtained from Jupiter’s rings, this ring is composed of irregularly structured objects that were probably formed by the disintegration of rock from the moons Metis and Adrasta.

Ulysses spacecraft

Ulysses was the result of the joint collaboration of NASA and the European Space Agency, which was launched in October 1990, and its main purpose was to study the space region above the poles of the Sun. Since Ulysses needed a lot of energy to orbit the Sun and the Earth was unable to provide this energy, it was necessary for this spacecraft to obtain its energy from another planet. Jupiter was the closest planet that could provide the prerequisites for this journey.

Ulysses reached Jupiter 16 months after separation from Earth and made its closest approach to the planet on February 8, 1992. Although the secondary purpose of Ulysses was to study Jupiter, in this short trip he was able to obtain very useful information about the very strong magnetic field of this planet.

New Horizons spacecraft

New Horizons was an interplanetary probe built at the Johns Hopkins University Physics Laboratory (APL) and Southwest Research Institute (SwRI) and launched in 2006 to study Pluto. New Horizons used Jupiter’s gravity (320 times that of Earth) to orbit Pluto.

New Horizons used the LORRI instrument to record its images of Jupiter on September 4, 2006, from a distance of 291 million kilometers from the planet. Closer examination of Jupiter continued in January 2007 with an infrared image of Callisto’s moon and several black-and-white images of Jupiter itself.

One of the main goals of this probe was to investigate atmospheric conditions and analyze the structure of Jupiter’s clouds. For the first time, this probe was able to record close-up images of Jupiter’s small red spot. He also managed to capture images of the ring system of the planet from different angles. New Horizons captured valuable information on Jupiter’s magnetosphere as it traveled towards it.

Juno spacecraft

NASA’s Juno spacecraft was launched on August 5, 2011, and entered Jupiter’s orbit on July 5, 2016, to begin detailed scientific studies of the planet. So far, this spacecraft has orbited Jupiter 32 times and spent almost a year at a distance of 5,000 km above Jupiter’s clouds.

The purpose of the Juno mission is to measure the composition, gravitational field, magnetic field, and polar magnetosphere of this planet. It also looks for clues about how the planet formed, its rocky core, the amount of water in the deep atmosphere, its mass distribution, and its deep winds, which reach speeds of up to 610 kilometers per hour.

Unlike other probes sent to the planets of the Solar System, Juno is powered by solar arrays similar to Earth satellites, while radiative isotope thermoelectric generators are typically used for intrasolar system missions.

Some images recorded by the Juno probe since 2016

During Juno’s mission, its infrared and microwave instruments will measure thermal radiation from Jupiter’s atmosphere. These observations are complementary to previous investigations of the planet’s composition regarding the abundance and distribution of water and oxygen. Data provides new insights into customer origin.

Juno also made unprecedented findings about Jupiter’s atmospheric winds. Based on these findings, the atmospheric winds of this planet last longer than the atmospheric processes on Earth. Juno’s measurements of Jupiter’s gravitational field confirm the planet’s north-south asymmetry, which is similar to the asymmetry observed in the planet’s belts and bands. As the winds get deeper, their mass increases.

According to one of Juno’s other findings, there is a solid body under the weather layer of this planet. This result is surprising, and future Juno measurements will help to understand this transition from the air layer to the solid body. Before the Juno discoveries, there was no information about the atmosphere near Jupiter’s poles. According to the data obtained from this probe, Jupiter’s poles are rougher in nature compared to the more familiar white and orange belts located in the planet’s lower latitudes.

The north pole of this planet is surrounded by a central cyclone, which itself is surrounded by eight far-polar cyclones with diameters varying from 4000 to 46000 km. Jupiter’s south pole also has a central tornado that is surrounded by five other tornadoes with diameters ranging from 5,600 to 7,000 km. The Juno spacecraft is currently surveying Jupiter from the planet’s orbit, sending back stunning images, atmospheric data, and other observations about the planet.

Images by James Webb of Jupiter

The James Webb Space Telescope, which has been operating since last year, has made impressive observations in the last few months. One of these remarkable observations is the detailed images of the planet Jupiter and its auroras. Both images of this telescope are composites, that is, they are made from the combination of several images that were taken with the telescope’s near-infrared camera (NIRCam) and photographed with different filters.

A composite image of Jupiter captured by the NIRCam camera shows the planet’s rings and its two moons, Amalthea and Adrastia. The blue halo around Jupiter’s poles are the auroras.

In the wider image, you can see Jupiter’s narrow rings as well as its two moons. In this detailed James Webb image of Jupiter, the moon Almatia is a bright dot on the left and the moon Adrastia is at the edge of the rings between Almatia and Jupiter. The second image is a close-up view of the planet Jupiter. In this image, three filters are used to capture the details of the planet’s stormy atmosphere, especially the auroras. You might be wondering why the colors in these images are not the same as what we see in other customer images. In these images, the James Webb telescope recorded light in the infrared spectrum, not the visible light spectrum; Therefore, the colors of the two images are not the same as the colors of the unaided eye. The infrared data was mapped onto the visible light spectrum so these images are “false color” rather than “true color”.

A composite image of Jupiter captured by the James Webb Space Telescope’s NIRCam camera; The orange glow around the poles are auroras.

Future missions to the client

JUICE ( Jupiter’s Icy Moons Probe): Jupiter’s Icy Moons Probe (JUICE) is a European Space Agency mission selected as part of the Cosmic Vision science program. The probe is expected to launch in 2022 and reach Jupiter in the 2030s after visits to the inner solar system. This probe is dedicated to studying the icy Galilean moons: Ganymede, Callisto, and Europa. All three moons have subsurface oceans, which increases their potential for discovering life.

Europa Clipper: NASA’s Europa Clipper probe is dedicated to the study of Europa, Jupiter’s icy moon, and will investigate the conditions of life beneath the icy crust of this moon. This probe will be placed in Jupiter’s orbit for close observation of Europa. The Europaclipper probe will be launched in the early 2020s and will reach Jupiter after a 6.5-year journey.

Chinese and Russian missions: China will also launch its first probe to Jupiter in 2029. This probe will reach Jupiter in 2036. Also, Russia is looking to send a probe to Jupiter that will be launched in 2030. This mission will last 50 months and will initially visit the Moon and Venus. Then he examines Jupiter and its moons.

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