From the vastness of the solar system and its strange moons to the ubiquitous presence of water and organic molecules, our solar neighborhood is full of surprising facts.

25 surprising facts about the solar system

Our solar system includes the sun and everything that revolves around it; Among the eight planets that we have all been familiar with since elementary school. But the main planets, despite their diversity and charm, are only part of the wonders of our cosmic neighborhood. Planet Earth’s neighbors in space include comets, asteroids, dwarf planets, mysterious moons, and a series of phenomena so strange and alien that they are not easily explained.

Table of Contents

• 1. The solar system is very, very large
• 2. Even our neighborhood is very big
• 3. Uranus orbits the Sun sideways
• 4. Jupiter’s moon Io is full of volcanic eruptions
• 5. Mars has a volcano that is bigger than the entire state of Hawaii
• 6. The biggest canyon on Mars could take Earth’s Grand Canyon in one bite
• 7. Venus is swept by super-powerful winds
• 8. Water is everywhere
• 9. Human spacecraft have visited all planets
• 10. Pollutants may be transported to habitable areas
• 11. Mercury is shrinking
• 12. Pluto has mountains
• 13. Pluto has a strange atmosphere
• 14. Rings are more common than you might think
• 15. Jupiter’s Great Red Spot is shrinking
• 16. Most comets are detected with solar telescopes
• 17. The ninth planet
• 18. Neptune is very hot
• 19. Earth’s Van Allen Belt is much stranger than expected
• 20. What happened to Miranda?
• 21. Saturn’s yin-yang moon
• 22. Titan has a liquid cycle, But there is no water involved
• 23. Organic molecules are everywhere
• 24. Saturn has a hexagonal storm
• 25. The atmosphere of the Sun is much hotter than the surface of the Sun

From fascinating glaciers on the dwarf planet Pluto and a deep valley the size of the United States on the Red Planet to the possibility of a giant, undiscovered world known as the ninth planet beyond Neptune, the space around Earth is full of wonders. Stay tuned to Zoomit for some of the weirdest facts about the solar system.

25 surprising facts about the solar system

1. The solar system is extremely large

By including the Oort cloud, our star’s realm becomes much, much larger.

NASA’s Voyager 1 spacecraft began its mission in 1977, and more than three decades later in 2012, it became the first man-made object to enter interstellar space by passing through the heliopause or heliosphere boundary. The heliopause is the region where the magnetic fields and most of the particles emitted from the sun disappear.

However, according to NASA, “If we define our solar system as the Sun and primarily everything that orbits it, Voyager 1 will continue to remain within [dominance of] the Sun until, in the next 14,000 to 28,000 years, Get out of the Everett cloud. 

2. Even our neighborhood is very big

Did you know that all the planets in the solar system can fit between the Earth and the Moon?

Depending on how accurately you do the math and how you arrange it, all the planets in the solar system can fit between the Earth and the Moon. The distance between the Earth and the Moon varies as does the diameter of each of them. Our planet and its moon are wider at their equator; As a result, Saturn or Jupiter or both must be slightly tilted to the sides to fit between them. However, if you lined up the planets from pole to pole, they would barely fit between us and our only space companion, blocking the sky with their rings and huge gas masses.

The moon is the farthest object humans have ever traveled to, and depending on how you think about it, it’s both amazingly far and incredibly close. Eight giant planets of the solar system can fit in the space between us and the moon, and yet, the distance from the Earth to the sun is more than 390 times the distance from the Earth to the moon.

Scientists use the approximate distance from the Earth to the Sun, known as an astronomical unit, or AU, to compare distances within the solar system. Jupiter is approximately 5.2 AU from the Sun and Neptune is 30.07 AU or approximately 30 times the distance from Earth to the Sun from our star.

 3. Uranus orbits the sun sideways

This composite image of the two hemispheres of Uranus was obtained with the adaptive optics of the Keck telescope. The north pole of the planet is at 4 o’clock.

In solar system models, Uranus usually appears as a blue ball with no special features; But this gas giant, located in the outer limits of the solar system, is very strange from a global perspective. First of all, the seventh planet of the solar system has a very extreme axial deviation of 97.77 degrees; This means that it rotates sideways and completes its orbit around the sun like a rolling ball. The most likely explanation for the planet’s unusual orientation is a catastrophic collision with another body in the distant past.

The tilt of Uranus has caused NASA to witness the most unusual seasons in the solar system on this planet. In about a quarter of each Uranian year (equivalent to 21 Earth years), the Sun shines directly on the north or south pole of the planet; This situation means that half of Uranus does not see the Sun at all for more than two Earth decades.

Scientists have been monitoring these temperate seasons on Uranus and predicting that they will witness unusual weather on this planet at the moment of the 2007 equinox. But it was seven years later that unexpected violent storms occurred in the atmosphere of Uranus, and the planet became a bigger mystery than ever. 

4. Jupitor’s moon Io is full of volcanic eruptions

Io has hundreds of active volcanoes. In this image, the moment of the spectacular eruption was captured by NASA’s Galileo spacecraft as it flew over the moon.

Jupiter’s moon Io may seem like a world of surprise compared to Earth’s silent moon. This Galilean moon, which is slightly smaller than the Earth’s moon, has hundreds of volcanoes and is considered the most active moon in the solar system. Io sends masses of sulfur smoke up to 300 km into its atmosphere. According to NASA, Io’s volcanoes emit a ton of gas and particles every second into space near Jupiter.

The eruptive nature of Io is due to the enormous forces that this moon is exposed to. Trapped in Jupiter’s gravitational well and magnetic field, Io experiences constant tension and relaxation as it moves away from the planet and approaches it, gaining enough energy for volcanic activity.

Scientists are still trying to figure out how heat is distributed inside Io. However, it is difficult to predict the location of volcanoes using only scientific models. 

5. Mars has a volcano that is bigger than the entire state of Hawaii

Mount Olympus is the largest volcano discovered in the solar system.

Although Mars seems peaceful now, giant volcanoes once ruled the planet’s surface. One of these volcanoes is Mount Olympus, the largest volcano discovered in the solar system. With a width of 602 km, Olympus can be compared to the state of Arizona in America. The height of this volcano is 25 km or three times higher than Everest, the highest mountain on earth. According to NASA, Olympus is 100 times larger in volume than Mauna Loa, the largest volcano on Earth in Hawaii.

Scientists suspect that volcanoes can grow to such enormous sizes on Mars because of Mars’ weak gravity compared to Earth’s. Moreover, while the earth’s crust is constantly moving, the crust of Mars is probably stationary based on the belief of some researchers. If the surface of Mars does not move, a volcano can form in one spot for a longer period of time. 

25 surprising facts about the solar system

6. The biggest canyon on Mars could take Earth’s Grand Canyon in one bite

Mariner Canyon on Mars is more than 10 times longer than the Grand Canyon on Earth.

The huge system of Martian canyons, known as the Mariner Canyon, is 4,000 kilometers long, more than 10 times larger than the Grand Canyon on Earth. Mariner Canyon was overlooked by early Martian spacecraft that flew over other parts of the planet and was finally discovered by the Mariner 9 probe in 1971. If the Mariner Valley was located on Earth, it could stretch from the East Coast to the West Coast of America.

The lack of active plate tectonics on Mars makes it difficult to discern how Mariner Valley formed. Some scientists think that a chain of volcanoes on the other side of the planet, known as the Tharsis Plateau, which includes Mount Olympus, somehow bent the crust away from Mars. That destructive force created fissures in the crust, exposed vast amounts of groundwater to excavate the rocks, and formed glaciers that opened new routes into the canyon system. 

7. Venus is swept by super-powerful winds

This artistic image shows the rocky surface of Venus and sulfuric acid clouds.

Venus is a hellish planet with a high temperature and pressure environment on its surface. The second planet in the solar system is extremely dry and hot enough to melt lead and has probably never had an environment conducive to supporting life. When the heavily protected Venus spacecraft from the Soviet Union landed on Venus in the 1970s, each lasted only a few minutes, or hours at most, before melting or shattering.

However, Earth’s infernal twin has a far stranger environment beyond its surface. Scientists have found that the winds in the upper atmosphere of Venus blow 50 times faster than the rotation of the planet. The European Venus Express spacecraft, which orbited Venus between 2006 and 2014, tracked the winds over long periods and detected periodic changes. The probe also showed that powerful winds appear to be getting stronger with time.

A study in 2020 pointed to the presence of phosphine, which is a possible sign of the decay of biological materials, in the clouds of Venus. This study initially excited some astrobiologists, But the supplementary research firmly rejected the possibility of the existence of life in the dry and windy atmosphere of Venus. 

8. Water is everywhere

This artistic rendering shows what Mars would look like with water lakes.

At one time, water was considered as a rare substance in space; But the truth is that water ice exists throughout the solar system and is a common constituent of comets and asteroids.

Water can be found as ice in the permanently shadowed craters of Mercury and the Moon. However, we don’t know if there is enough water to support possible human settlements in those places. Also, Mars has ice on its poles. Even smaller solar system objects, such as Enceladus, Saturn’s moon, and the dwarf planet Ceres, have ice.

NASA scientists believe that Jupiter’s moon Europa is the most likely candidate known to support extraterrestrial life; Because contrary to all expectations, liquid water is probably flowing under its cracked and frozen surface. Europa, which is much smaller than Earth, probably has a deep ocean that researchers believe contains twice as much water as all the oceans on Earth combined.

However, we know that not all ice is the same. For example, a close examination of comet 67P/Churyumov-Grasimenko by the European Space Agency’s Rosetta spacecraft revealed a different type of water ice than that found on Earth. 

9. Human spacecraft have visited all planets

The outer planets of the solar system as seen by the Voyager 2 spacecraft.

We’ve been exploring space for over 60 years and have been lucky enough to get close-up images of dozens of celestial bodies. Most importantly, we have sent spacecraft to all the planets in the solar system, including Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, as well as the two dwarf planets, Pluto and Ceres.

Most of the close flybys of the planets were made by NASA’s Voyager twins, which left Earth more than four decades ago and are still transmitting data from interstellar space to this day. Voyagers met all of them during their long journey, thanks to a rare alignment of the outer planets. 

10. Pollutants may be transported to habitable areas

Hydrothermal vents in the ocean.

Scientists have not yet found evidence of life in other parts of the solar system; But as they learn more about the hardy microbes that inhabit Earth’s harsh environments, such as ocean-floor hydrothermal vents or frozen environments, they have more opportunities to find alien life on other planets.

Currently, the presence of microbial life on Mars is considered so probable that scientists take special precautions to clean spacecraft bound for this planet. NASA decided to crash the Galileo spacecraft into Jupiter to avoid the risk of contaminating Europa’s potentially habitable oceans. 

Read More: Will Earth one day become a wandering planet?

25 surprising facts about the solar system

11. Mercury is shrinking

Mercury, the smallest planet in our solar system, has short years, long days, and extreme temperatures.

With the exception of the dwarf planet Pluto, Mercury is currently the smallest planet in the solar system and the most dense planet after Earth. However, the innermost planet in our solar neighborhood is shrinking and becoming denser.

For many years, scientists believed that Earth was the only tectonically active planet in the solar system. But after NASA’s MESSENGER spacecraft, performing its first orbital mission on Mercury, mapped the entire planet in high resolution and took a look at its surface features, this belief changed.

In 2016, MESSENGER data revealed chasm-like features known as fault chasms. Because these fault chasms are relatively small, scientists are confident that they did not form long ago and that Mercury is still contracting, 4.5 billion years after the formation of the solar system. 

12. Pluto has mountains

In July 2015, NASA’s New Horizons spacecraft sent back impressive images of Pluto and its moons.

Pluto is a small world at the edge of the solar system; As a result, scientists thought that this dwarf planet would have a completely uniform environment full of craters. But this belief changed in 2015. That year, NASA’s New Horizons spacecraft flew past Pluto and sent back unprecedented images, forever changing the way we look at this distant object.

Among the amazing discoveries of New Horizons, there were icebergs with a height of 3,300 meters; A finding that suggests Pluto must have been geologically active at least 100 million years ago. But geological activity requires energy, and the source of this energy inside Pluto is a mystery. The Sun is too far away to generate enough heat for geological activity, and there are no large planets close enough to Pluto to cause such a gravitational disturbance. 

13. Pluto has a strange atmosphere

NASA’s New Horizons spacecraft took this image of Pluto from a distance of 200,000 km. Pluto’s atmosphere can be seen as a blue haze.

Pluto’s observed atmosphere disproved all predictions. The scientists observed that the dwarf planet’s unexpectedly hazy atmosphere extends up to 1,600 km and extends beyond the Earth’s atmosphere, away from the surface. When data from NASA’s New Horizons mission came in, scientists began analyzing the nebula and discovered some surprises there as well.

Scientists have found nearly 20 layers in Pluto’s atmosphere that are both colder and denser than expected. This feature affects calculations related to the rate of loss of Pluto’s nitrogen-rich atmosphere in space. The New Horizons team found that thousands of kilograms of nitrogen gas escape from the dwarf planet every hour; But Pluto somehow manages to continuously replenish the lost nitrogen. The recovery of this gas is probably done mostly through geological activities. 

14. Rings are more common than you might think

Saturn is not the only ringed object in the solar system.

Since the invention of telescopes in the 17th century, we have known about the existence of rings around Saturn; But to reveal more rings, we needed the powerful spacecraft and telescopes built in the last 50 years. We now know that all the outer planets of the solar system, including Jupiter, Saturn, Uranus, and Neptune, have ring systems.

However, the rings vary from planet to planet: Saturn’s spectacular ring, which is partly made of glowing, reflective water ice, is unmatched anywhere else. In contrast, the rings of other giants are probably made of rocky particles and dust.

Rings are also not limited to planets. For example, in 2014 astronomers discovered rings around the asteroid Chariklo. 

15. Jupiter’s Great Red Spot is shrinking

Jupiter’s Great Red Spot is the largest storm in the solar system.

Besides being the largest planet in the solar system, Jupiter also hosts the largest storm in the solar neighborhood. This red storm, known as the Great Red Spot, has been observed in telescopes since the 17th century and studied with modern instruments such as NASA’s Juno probe. The spacecraft has recently provided evidence that Jupiter’s giant storm is hundreds of kilometers high and is likely fed by winds thousands of kilometers below. This storm has been a complex mystery for centuries; But in recent decades, another secret has been revealed: the Great Red Spot is shrinking.

In 2014, Jupiter’s Great Storm was only 16,500 km wide, roughly half its historical size. This diminution is monitored by professional telescopes as well as amateur astronomers. Amateurs can often take more consistent measurements of the client; Because the observation time in larger and professional telescopes is limited and is often divided between different objects. 

25 surprising facts about the solar system

16. Most comets are detected with solar telescopes

Comet Ison appears from the lower right of the image and moves to the upper right. This impressive image was captured by the Horspeary Solar Observatory, and the image of the Sun in the center was obtained from NASA’s Solar Dynamics Observatory.

Comets used to be the domain of amateur astronomers who probed the sky night after night with their telescopes. Although some professional observatories also made discoveries while observing comets, the status of explorations in this field started to change with the launch of the Solar and Horseshoe Observatory (SOHO) in 1995.

Since then, SOHO has found more than 2,400 comets. This volume of comet discovery has been a very fruitful side mission for a probe that only observes the Sun. The nickname of these comets is “Sunriser” or “Solstice”. Many amateur astronomers continue to help find these objects by identifying comets in raw SOHO images. One of SOHO’s most famous observations was when it observed the collapse of the bright comet Ison in 2013. 

17. The ninth planet

A ninth planet is a hypothetical world that could explain the motion of some Kuiper belt objects.

In January 2015, California Institute of Technology (Caltech) astronomers Konstantin Batygin and Mike Brown, relying on calculations and mathematical simulations, announced that a giant planet might be hidden far beyond Neptune. Now several teams are searching for this hypothetical “ninth planet” and research shows that it is possible to discover it within the next decade.

A ninth planet, if present, could help explain the motions of some objects in the Kuiper Belt (an icy collection of objects beyond Neptune’s orbit). Brown has already discovered several large bodies in that region, in some cases rivaling Pluto in size. In fact, his discoveries were the catalyst for Pluto’s status change from a planet to a dwarf planet in 2006.

But some scientists follow another theory; That “Planet Nine” might actually be a black hole the size of Grapefruit that bends space just like a giant planet. However, another team suggests that the strange movements of the Kuiper belt’s distant inhabitants are likely the collective effect of several small objects; No undiscovered planets or black holes. 

18. Neptune is very hot

The distance of Neptune from the Sun is approximately 30 AU.

Neptune, the outermost planet in the Solar System, is 30 times farther from the Sun than Earth and receives less light and heat. However, Neptune emits much more heat than it receives and has a much more active atmosphere than its neighbor Uranus. Uranus is closer to the Sun, yet emits nearly as much heat as Neptune. Scientists still do not know the cause of this problem.

The wind on Neptune can blow up to 2400 km/h. Does this amount of energy come from the sun, the planet’s core, or gravitational contraction? Researchers are trying to find the answer to this mystery. 

19. Earth’s Van Allen Belt is much stranger than expected

Discovered in 1958, the Van Allen belts are large bands of radiation that surround the Earth and expand and contract based on the activity of the Sun.

The Earth has several magnetically trapped bands of highly energetic charged particles around it, called the Van Allen Belts in honor of their discoverer. Although we’ve known about these belts since the dawn of the space age, the Van Allen probes, launched in 2012, provided the best possible picture of them and revealed many surprises along the way.

We now know that the belts expand and contract based on the activity of the sun. Sometimes the belts are very distinct from each other, and at other times, they swell as one large unit. An additional radiation belt, beyond the two known, was discovered in 2013. Understanding these belts helps scientists make better predictions about space weather or solar storms. 

20. What happened to Miranda?

Uranus’ moon Miranda has one of the most diverse landscapes of any extraterrestrial object.

One of the strangest outer moons of the solar system is Miranda. This mysterious moon of Uranus was observed only once in 1986; Voyager 2 caught a glimpse of it during its tour of the solar system. Miranda hosts sharp ridges, craters, and other large discontinuities on its surface that are usually the result of volcanic activity. Tectonic activity can cause the formation of such a surface, But Miranda is too small to generate that kind of heat on her own.

Researchers believe that the gravitational pull of Uranus could have caused the necessary pressure to heat, overturn, and deform Miranda’s surface. But to be sure, we need to send another spacecraft to investigate the unseen northern hemisphere of the moon. 

25 surprising facts about the solar system

21. Saturn’s yin-yang moon

Saturn’s moon Iapetus shows drastic differences in surface brightness depending on which side it faces the Sun.

Saturn’s moon Iaptus has a very dark hemisphere that always faces the planet and a very bright hemisphere that always faces Saturn. The brightness of most asteroids, moons, and planets is relatively uniform across their surfaces; But Iaptus sometimes shines so brightly that it was observed by the Giovanni Cassini telescope in the 17th century, and then dims considerably as it spins the other way.

Current research shows that Iaptus, also known as Saturn 8, is made mostly of water ice. According to scientists’ hypothesis, when the dark side of the moon faces the sun, water ice sublimates from that area and leaves behind darker rocks. Since dark matter heats up more than bright, reflective ice, this process may have created a positive feedback loop; In this way, when the darker and warmer part of the moon loses its ice, it heats up more easily when facing the sun and accelerates the loss of ice. 

22. Titan has a liquid cycle, But there is definitely no water involved

Titan’s lakes are full of methane and ethane and possibly a layer of water.

Another strange moon of the solar system is Titan, a moon of Saturn. Titan hosts a “fluid cycle” that moves material between the atmosphere and the surface. This circulation of materials is apparently very similar to the water cycle on Earth; But Titan’s huge lakes are filled with methane and ethane, probably on top of a layer of water.

Using data from the international Cassini mission, researchers hope to uncover some of the moon’s secrets before designing a submarine that could one day explore Titan’s mysterious depths. 

23. Organic molecules are everywhere

Organic molecules have been found in many places in the solar system, including comet 67P/Churyomov-Grasimenko. In this image, the rugged landscape of the comet’s core was captured by the Rosetta spacecraft.

Organics are complex carbon-based molecules found in living organisms, But abiotic processes can also be their creators. Although common on Earth, organic molecules can be found unexpectedly in many other places in the solar system. For example, scientists have discovered organic matter on the surface of comet 67pi. The hypothesis that organic molecules were probably brought to the surface of our planet from space to start life on Earth was strengthened by the discovery of these molecules in comet P67.

Organic matter has also been found on the surface of Mercury, Titan, Saturn’s moon (which gives it its orange color), and Mars. 

24. Saturn has a hexagonal storm

Saturn’s northern hemisphere is home to a strange hexagonal storm that has been raging for decades.

Saturn’s northern hemisphere has an intense six-sided storm known as the “hexagon”. This hexagon, a towering multi-layered storm, has existed for decades, perhaps even hundreds of years.

Saturn’s strange storm was discovered in the 1980s; But until the Cassini spacecraft flew between 2004 and 2017, it was difficult to observe it. Cassini images and data showed that the hexagonal storm is 300 km high and 32 thousand km wide and consists of air moving at a speed of 320 km/h. 

25. The atmosphere of the Sun is much hotter than the surface of the Sun

The temperature of the sun is different in each layer of its atmosphere.

While the temperature of the visible surface of the sun or photosphere is 5500 degrees Celsius, the temperature of the upper atmosphere or corona (solar corona) reaches millions of degrees. This extreme temperature difference is one of the great mysteries of the star of our system.

However, NASA has several solar-observing spacecraft in its fleet of probes, and they have some hypotheses for how heat is generated in the sun. One such idea is the “heat bombs” that occur when magnetic fields align in the corona. Another hypothesis is related to the time when plasma waves move from the surface of the Sun to the corona.

With new data from the Parker probe, which has become the closest man-made object to the Sun,we are closer than ever to unlocking the secrets of the heart of the Solar System.