When we analyze all the planets in the solar system , we have to divide them into two types according to their location: inner planets and outer planets . Today we're going to focus on explaining what the outer planets are and their main characteristics. These planets are those located beyond the asteroid belt. These planets are known as gas giants.
In this article we are going to tell you about the characteristics of the outer planets and some curiosities.
Outer planets
As we mentioned at the beginning of the article, the outer planets are those located beyond the asteroid belt. Among the main characteristics of these planets is that they are known as gas giants. This name comes from their morphology. These planets are large masses of gas orbiting the sun. While it's true that these planets have a solid core, if you didn't pass directly through the center, you could pass right through them.
It's important to remember that, as of today, Pluto is not considered a planet. The outer planets include Jupiter , Saturn , Uranus , and Neptune . All of these planets share similar characteristics. For a celestial body to be considered a planet, it must meet certain criteria. The first is that it cannot emit its own light. The second is that it must be large enough that gravity is not constantly reshaping its form. Finally, the third rule is that it must be large enough that its gravity is strong enough to attract surrounding objects and clear other bodies from its orbital zone.
Another requirement that isn't universally agreed upon by the scientific community is that they must orbit a star. Some characteristics these outer planets share are that they are surrounded by rings and have many moons. To learn more about how they formed, you can read the article on how planets form . We'll now analyze each of the outer planets and describe their main characteristics.
Jupiter
Jupiter is the largest planet in the entire solar system. Its mass is twice that of all the other planets combined. Compared to Earth, Jupiter is 1317 times larger . If you go to its surface, you can see that as you move closer to its core, the gases become increasingly compressed. These gases are hydrogen, helium, and argon. These three gases are the main elements found in Jupiter. As we approach the core, these gases become even more compressed, giving it a rocky appearance.
Further along, we see that the core is a rocky formation composed of these elements, but in a frozen state. No rock has been found there to date. This is the origin of the gas giant's name. One of Jupiter's most striking features is its Great Red Spot. This spot indicates a powerful storm that appears to have formed more than three centuries ago and is still active today. Given the planet's size, the Great Red Spot seems small. But when compared to Earth's diameter, it is much larger.
This planet has the fastest rotation speed in the entire solar system. A day on this planet lasts only 10 hours. However, it takes 12 years to orbit the sun. It has approximately 60 moons, all of which are very famous. It is the oldest planet in the entire solar system. If you want to learn more about gas giants, I recommend reading the article on gas giants.
Saturn
Saturn is the planet best known for its rings. It is the only one whose rings are visible from Earth. Saturn is 750 times larger than Earth . Around 62 moons orbit it. One of them is well-known as Titan, and it is believed to have had an atmosphere similar to ours long ago. It is not the only planet with rings, but it has the most. The rings are made up of very small elements, some the size of a grain of sand. Other elements, some the size of a mountain, are also found in the rings.
Its rotation period is not well understood because it lacks a solid surface. Its atmosphere rotates at varying speeds, depending on latitude. Similar to Jupiter, hydrogen and helium are the primary gases in its atmosphere. Its orbital period is 30 years. If you'd like to learn more about planets with rings, you can consult the article on planets with rings.
One of the planet's notable characteristics is its strong winds. These include clouds formed by ammonia crystals and strong winds of up to 450 meters per second. At its north pole, there is a cloud formation for which science still has no answer. It is known as the Saturnian hexagon.
Uranus
Uranus has a core, but unlike the other planets, it is covered by an icy mantle that extends to the surface. Its atmosphere is composed primarily of hydrogen and helium. The core is quite small. It's worth noting that Uranus appears bluer because almost its entire surface is covered in ice.
Its orbital period is 84 Earth years, and it is located at an average distance of 3.000 billion kilometers from the Sun. Its rotation is not well understood because it is not uniform across all latitudes. One of the characteristics that makes this planet unique is the tilt of its axis. This causes one of its poles to always face the Sun. This is the reason why Uranus has periods of 42 light-years and 42 years of darkness. If you would like to learn more about exoplanets, visit exoplanets.
Neptuno
It is the outermost of the planets. It is the most distant planet in the entire solar system. It is also the smallest in size, although it is still the fourth largest in the solar system by diameter. Its gravity is very similar to Earth's, despite its smaller size. Its rocky core is composed of silicates, nickel, and iron . A large, icy mantle and an atmosphere composed primarily of hydrogen, helium, and methane gas characterize this planet.
This atmosphere also contains some violent storms with winds reaching speeds of up to 2200 kilometers per hour . Currently, 14 satellites are known to orbit around it. The most famous of these is Triton.
I hope that with this information you can learn more about the outer planets and their main characteristics.