The most important feature of the planet Jupiter is its extreme heaviness. Thanks to its gravitational pull, Jupiter plays the role of the big brother in the solar system, as it has played a role in many historical events. Four billion years ago, the gravitational force of Jupiter along with Saturn threw comets and asteroids into the solar system. Such an event led to a period of massive upheaval known as the Late Heavy Bombardment. During this period, asteroids bombarded the inner part of the solar system and created many impact craters that we see on the surface of the moon today.

In the past 50 years, space missions and the construction of powerful telescopes have allowed scientists to reach beyond Jupiter’s clouds and dissect the planet with unprecedented clarity. Scientists also found that Jupiter’s environment is very harsh. Long-lasting storms swirl around the planet, covering its surface with multicolored stripes. Lethal levels of radiation can roast any object approaching the planet. Like their host planet, the Galilean moons are turbulent worlds.

The planet Jupiter, with its swirling mantle and turbulent nature, has inspired people’s imaginations as well as scientists’ research for years. Research in recent years has made researchers more interested in investigating the nature of this distant world than before. In this article, we discuss some of the most fascinating discoveries made about Jupiter and its moons in the last fifty years.

As a gaseous planet, Jupiter is not rocky and the nature of its core is unclear. The central core of this planet is a dilute mixture of heavy element solids and gases compressed by gravity. In fact, the planet Jupiter has a consistency similar to bubble tea; In this way, it is still soft on the outside, but it is somewhat hardened in the middle and ends up with a dense core.

In 2017, the Juno probe revealed details of Jupiter’s strange interior through measurements of its gravitational field. In this technique, small changes in the gravitational pull imposed on the probe are recorded. In this case, the gravity data did not resemble planets with precise solid-liquid boundaries, leading scientists to conclude that Jupiter has a fuzzy core. “We still don’t know exactly what’s going on inside Jupiter,” said Heidi Becker, a NASA planetary scientist and one of the leaders of the Juno probe.

Understanding Jupiter’s core can reveal clues to how the planet formed. Most protoplanets form by accreting solids until they become heavy enough and then gather gases around them. To describe Jupiter’s data, scientists hypothesized that Jupiter may never stop accumulating solids as it grows; As a result, the planet may be an uneven mixture of solids and gases from the center to the surface.

According to another hypothesis, a massive impactor similar in size and weight to Jupiter crashed into it, disrupting its interior and blurring the boundary between the mantle and the core.

Earth’s magnetic field originates from the molten and rotating iron inside the core, which creates a kind of driving force. In Jupiter, a rare type of material called metallic hydrogen strengthens the magnetic field.

Jupiter’s heaviness means its strong pressure on the core and causes the formation of a strange substance that does not exist in other parts of the solar system. Hydrogen, which is the lightest element in the periodic table and is usually seen as a gas, is compressed in Jupiter to the point where its electrons are separated from its atoms and move freely.

The sea of ​​free electrons creates a kind of driving force and a very strong magnetic field. Jupiter’s sphere of magnetic influence is even wider than that of the Sun. This magnetosphere is large enough to shield the planet from the solar wind and deflect solar particles up to Saturn’s orbit. In fact, Jupiter may even be an elusive target for the solar wind, but the planet and its moons emit their own energetic particles. These particles are trapped and accelerated by the magnetic field that shields Jupiter from ion bombardment.

The charged particles originate from Jupiter’s moon Io, whose volcanic material is stirred up by the escape of electrons from their molecules. Free electrons travel around Jupiter at nearly the speed of light, emitting radio waves. These radio waves are problematic from a scientific perspective because they interfere with the radar signals that scientists send from Earth to probe Jupiter’s interior.

The electron beam also creates a belt of beams that slam into visiting spacecraft. Considering all these obstacles, scientists built the Juno probe like an armored tank, so that all its sensitive electronic components are housed in an electron-shielding titanium dome, which weighs approximately 181 kilograms.

It should be mentioned that the strong magnetosphere of Jupiter creates impressive auroras. This happens when electrons moving in different directions collide with atoms in the atmosphere and create light bursts. Due to the fact that the magnetic field is large enough to cover the moons, it will direct the lava emitted from Io to another point. Scientists have also seen these pollutants on Europa, another moon of Jupiter hundreds of kilometers away from Io.

Jupiter is always hot

Jupiter has not cooled since its early days and has been emitting heat since billions of years ago. Scientists believe that this heat helps to strengthen the strong storms that engulf Jupiter’s atmosphere.

In 1979, the Voyager probe measured the amount of heat emitted by this gas giant while passing by Jupiter. Scientists found that Jupiter was emitting more heat than the models predicted: some parts of the planet were burning at temperatures of 426 degrees Celsius, more than researchers expected.

The mystery of Jupiter’s hidden heat was solved four decades later when scientists at the Keck Observatory began mapping Jupiter’s temperatures. The planet had the coldest temperature near the equator and the hottest temperature near the magnetic poles, where the auroras shine brightly. This finding indicated that auroras are a source of additional heat. Io’s plasma collides with Jupiter’s atmosphere to produce spectacular auroras. This plasma moves in the opposite direction of Jupiter’s fast winds to provide enough friction to raise the global temperature.

Jupiter’s relationship with its moons goes beyond the exchange of chemicals. The planet can also heat its moons through its gravitational field. This long-range heating is visible among the four Galilean moons. Jupiter’s gravitational field has turned these moons into the fascinating worlds they are today.

According to University of California planetary scientist Michael H. Wong, the Galilean moons aren’t the only heavy stationary objects in space that have been bombarded. Rather, these moons have internal activities through a mechanism known as lethal heating. With the moons dancing at near and far distances from Jupiter on elliptical orbits, the gravitational pull battle between the moons and Jupiter provides enough friction to cook them.

Consequently, the Galilean moons do not resemble dead worlds like Earth’s moon. Of the four moons, Io experiences the full wrath of Jupiter’s gravity. Compared to its parent planet, Io is the most volcanically active moon in the entire solar system. Its icy sister Europa not only bears no resemblance to this volcanic world but has a vast ocean of liquid water beneath its frozen crust. Europa is a prime target in the search for planetary habitability because it is temperate enough to potentially harbor life, thanks to Jupiter’s lethal heating processes.

Although 90% of Jupiter’s atmosphere consists of hydrogen, its air is full of other elements that cause the beautiful white and orange colors on the surface of this gas giant. On Jupiter’s surface, molecules of acetylene, hydrogen sulfide, and phosphine cover the face of the planet in swirling currents.

The Galileo probe landed on Jupiter’s gaseous body in 1995 and got a brief view of it. According to the findings of this probe, Jupiter has three types of clouds: clouds made of ammonia, ammonium hydrosulfide clouds, and water ice clouds. As a result, different types of rainfall are based on the height in Jupiter’s sky.

The Galileo probe also discovered a surface rich in heavy gases, far beyond what scientists expected. This chemical clue points to a vibrant past. Jupiter probably formed at a distance from the Sun where it was cold enough to absorb ice and frozen gases. According to the theories, the gas giant gradually moved towards the Sun until Saturn stopped it from moving further towards the Sun. Otherwise, Jupiter would probably be swallowed by the sun.

Jupiter is home to some of the most impressive storms, with the Great Red Spot being one of the most well-known. This is a tornado with a speed of 643 km/h and a depth of 482 km. Although the Great Red Storm has lasted for more than two decades, it is shrinking today. The dimensions of the eye of the storm in the past were three times the size of the earth, and today its size has reached one earth; But despite the reduction in size, it is still the largest living storm in the solar system.

Jupiter’s upper atmosphere hosts thunderstorms. In 2020, when Juno placed its camera on the planet’s dark side, it detected faint flashes of light that were lightning bolts. On Earth, lightning occurs when ice particles and water droplets in clouds collide with each other and lead to the separation of positive and negative charges.

At first, scientists thought that the formation of lightning on the surface of Jupiter was impossible and they thought that the temperature at this altitude was too cold for the existence of liquid water; But Jupiter has enough liquid water in its upper atmosphere thanks to ammonia gas that acts as an antifreeze.

Storms can also throw ice particles from the depths, and when the ice hits ammonia, it creates a ball of water and ammonia, which is a type of hail containing solid ice and liquid water. When it rains, these balls absorb the remaining ammonia gases on their way, and this phenomenon can explain the absence of ammonia in the atmosphere.

Jupiter’s rings are too thin to be observed with a telescope, so they were not revealed for a long time. These rings were discovered in 1979 during a low-altitude flyby of the Voyager spacecraft and have since been observed by powerful ground-based telescopes and other spacecraft.

Jupiter, like other ringed planets, has a ring field made of pebbles. This ring is made up of fragments of disintegrated meteorites that have gathered around Jupiter. This loose and irregular mixture of rock, ice and dust covers a distance of 51,500 km to 209,214 km from the surface of the planet.

As other objects pass through the ring, they may leave trails in the dust stream. One of these collisions was the fall of Comet Shoemaker Levi 9 on Jupiter in 1994. Years later, the Galileo and New Horizons probes found oscillations in Jupiter’s rings caused by fragments of the comet.