What do we know about the giants of the solar system?

Joyful ggaseous ligands They are very large planets composed mostly of gases such as hydrogen and helium. They even have a rocky core, but very small compared to the size of the atmosphere.

also solar system There are four of these exotic worlds. are they Jupiter, Saturn, Uranus and Neptune. Expression “gas giant“has an interesting origin. Evidence suggests it was first used in a sci-fi game by James Blish in 1952.

Back then, before the era of space exploration, everything we knew came from telescopic observations. 20 years later, in 1972, the Pioneer 10 made its maiden flight. Jupiter and we were able to authenticate our neighbors.

Despite being grouped together in the same category, our gas giants are quite different from each other. Jupiter and Saturn much bigger Uranus and Neptune. In addition, the composition of the atmospheres of each of them also has its own characteristics. See below for details on each.

Jupiter

Jupiter It is the largest planet in our solar system, with a diameter of 22 times that of Earth. It can be seen in the night sky with the naked eye, so it was already known to the ancient peoples.

Most of its mass is believed to consist of liquid metallic hydrogen. This theoretical substance can only exist under very high temperature and pressure conditions and creates a very strong magnetic field.

The planet’s magnetism creates an interesting phenomenon. It is responsible for the aurora both north and south, a light show at the north and south poles, just as it is here on Earth. But there they shine brighter than anywhere else in the solar system.

The rotation of this giant takes only 10 Earth hours. Translation is slower, taking 12 years to complete one revolution around the Sun.

And Jupiter has rings too. They were discovered by the Voyager spacecraft in 1979, but they are much less spectacular than those on Saturn. They consist of more dust and less ice, so they reflect less sunlight.

The conditions on the planet are very unfavorable, as it is gaseous and cold. But Jupiter may harbor life elsewhere: on one of its moons. Today, 79 of them have been confirmed, and the best-known ones were discovered by one of the most prestigious astronomers ever, Galileo Galilei.

Timelapse captured by the Cassini space probe as Europa and Io orbit Jupiter

via NASA-JPLs @kevinmgill pic.twitter.com/5BzKTsxlLl

– Latest in space (@lastinspace) January 28, 2022

Four were discovered by him: Io, Europa, Ganymede and Callisto. And precisely in the latter, researchers believe that under the rocky surface there is a vast ocean. The hypothesis caused an outrage in the astronomical environment as it would allow the satellite to host life.

NASA’s Juno spacecraft arrived on the planet in 2016 and is seeking answers to our questions there. It adds to other efforts to better understand it, such as the use of the Hubble telescope.

Saturn

with a radius of about nine times the Earth, Saturn She is famous for her beautiful rings. It comes just after Jupiter in the solar system and has very similar atmospheres as both contain mainly helium and hydrogen.

As well as his partner Saturn It has been known since ancient times and can be seen with the naked eye. It is the second largest planet in the solar system. It is also the one with the most satellites. There are currently 82 confirmed, and just as with Jupiter’s Europa, some are capable of containing life.

Also in the rings are numerous “small moons”, smaller moons, with diameters ranging from 40 to 500 meters.

The rings stretch between 6,000 and 120,000 kilometers from the planet, with an average thickness of 20 meters. They are mostly composed of ice and dust, especially up to 10 meters in diameter.

There are two main hypotheses about the origin of the rings. The first says they are the remnants of an ancient moon that they destroyed. Saturn. The second assumes that these are remnants of nebular material from which the planet originated.

There’s still a lot we don’t know about this gas giant. For example, the full length of a day (return time).

Astronomers have tried to measure this period as the basis for the emission of radio waves, as with Jupiter, but the results are still inconclusive. It is estimated to take a little over 10 Earth hours. The translation is well known, it takes 29.5 years.

The Cassini spacecraft has completed more than a dozen years of observation of Saturn. But research is still advancing, and much remains to be done to unravel the mysteries of this giant.

Uranus

Uranus It was the first planet discovered with a telescope. It was the only way to see it, as it was invisible to the naked eye. The Voyager 2 spacecraft was the only spacecraft to visit it. In his images, the giant appears to have an almost uniform light blue surface with no clouds or deformations.

It’s the only one in the solar system which is “horizontal”, turning sideways. Also, to complete the weirdness, the translation movement is in a different direction than the others except Venus. This indicates that a major collision in the past turned the planet off its axis.

Uranus It takes a lifetime to go around the sun. Literally: the translation movement takes 84 years to complete. As seen from here, it takes about 7 years to pass through each of the zodiac constellations and 17 hours to return.

It is very different from the magnetic north and south poles as it rotates on its side. This causes some interesting seasonal effects. For example, imagine a world where the south pole points directly to the Sun, and the north where the darkness of night reigns.

Like other gas giants, Uranus has rings. They were first seen in 1977 and more than a dozen have been confirmed today.

Although not the outermost planet in the solar system, it is the coldest. All the heat that Uranus has comes from the Sun. Unlike here on Earth, it doesn’t have a core that can generate extra energy to heat it.

This dramatic time-lapse movie taken by the Hubble space telescope shows Uranus, its moons and seasonal changes on the planet [source: https://t.co/Cvbq9FOdac] pic.twitter.com/U2Cd8oiDrn

— Massimo (@Rainmaker1973) 24 May 2021

Uranus and its counterpart Neptune are often called ice giants because they have a slightly different composition than the two previous planets. Its atmosphere contains, in addition to hydrogen and helium, significant amounts of water, methane and ammonia, and traces of other hydrocarbons.

The planet also has several moons. There are a total of 27 people named after the characters in the works of famous English writers Shakespeare and Alexander Pope. The biggest ones are Miranda, Ariel, Umbriel, Titania and Oberon.

Neptune

Neptune it also has a radius of about four times that of Earth. Like Uranus, its atmosphere consists mainly of hydrogen and helium, with significant amounts of hydrocarbons such as methane and possibly nitrogen.

It was discovered in 1846 and was also visited by Voyager 2 only in 1989. In images taken by the probe, it still has a stronger blue color than Uranus, caused by an unknown compound or phenomenon.

There are a total of 14 confirmed satellites in its orbit. The largest and main one is Triton, which has a massive enough mass to take a spherical shape. Scientists believe the moon was once a dwarf planet in the past.

It just rotates in the opposite direction of the planet’s equator. This is strong evidence that this moon was captured by this world as it passed by and has been there ever since.

Neptune it also has a ring system, but these are broken up and formed by several springs. Researchers are unable to explain the reason for this phenomenon, because, according to the laws of rotational motion, the springs must propagate in a uniform ring over time.

Its translation takes 164.8 Earth years. This means that the planet only completed its first orbit around the Sun since it was discovered by us in 2011. Its return is estimated at 16 hours.

Neptune It has more total mass than its counterpart on Uranus. Still, it’s a little smaller. This is because huge amounts of matter create much more gravity, which compresses everything on the planet more tightly, making it more compact and denser.

formation

Astronomers believe these giants were once like rocky planets, only bigger. This size was different, however, because with the mass comes a strong gravitational field that can miss anything passing nearby.

This is how they began to combine hydrogen and helium from the gas cloud that existed here long ago when the Sun was still condensing. The larger orbits of Uranus and Neptune were damaged in the process. This also explains the more complex atmosphere of the last two.

It is also believed that most of its moons formed with them. This is implied as it rotates in the same direction as most rotations. But there are exceptions, such as Neptune’s moon Triton.

Gas giants have affected humanity since ancient times. No wonder they are all named after the most powerful Roman gods. And it’s no different these days.

With continued research, we are on the verge of experiencing new phenomena that are completely unlike anything we have witnessed in the past. Mainly with hitherto lesser known planets like Uranus and Neptune.

Launched in 2021, the James Webb telescope promises to be a lens for these scientific advances. He has a unique ability to shine a new light on these distant worlds. Astronomers promise: This is just the beginning of the journey.