What are (really) the planets of the solar system and their characteristics?

What are (really) the planets of the solar system and their characteristics?
Posted on 23-02-2022

What are the planets of the solar system?

The planets of the solar system are:

  • Mercury.
  • Venus.
  • Earth.
  • Mars.
  • Jupiter.
  • Saturn.
  • Uranus.
  • Neptune.

The planets are all the celestial bodies that revolve around a star, have enough mass to maintain their gravity, and can prevent other planets from interfering with its orbit.

On the other hand, the order of the planets of the solar system is determined by their proximity to the Sun. Therefore, Mercury is the closest planet, and Neptune is the most distant.

It is important to mention that until 2006, Pluto was considered the farthest planet in the solar system. However, it was removed from the list as its characteristics are not compatible with the current definition of a planet.

solar system



It is known as the "iron planet" because its composition is rich in this chemical element by at least 70%. The remaining percentage corresponds to elements such as helium, calcium, sodium, oxygen, and magnesium.

The body of the planet is rocky and is characterized by the presence of craters, the result of the multiple impacts of smaller celestial bodies.

On the other hand, Mercury is not only the closest planet to the Sun, it is also the smallest in the solar system.



Venus is a rocky planet with size and composition similar to Earth, except for its atmosphere, which is composed of toxic gases. On the other hand, its core is nickel and iron.

The planet Venus lacks water, but studies carried out by NASA and released in 2019 concluded that until 700 million years ago it did have water and a stable atmosphere with conditions for the development of organic life.

Due to these conditions, Venus is a candidate planet for terraforming. It is a theoretical process of creating optimal conditions for life, generated with complex engineering systems.



Earth is the third planet orbiting around the Sun. Its terrestrial composition, the presence of water, and an atmosphere made up of oxygen, nitrogen, and water vapor (among other components), made it possible for the conditions for life to be generated.

Another characteristic of planet Earth is the existence of an ozone layer that protects all forms of life from solar radiation. This, and the presence of large masses of liquid water that make up 70% of the planet's composition, make Earth the only habitable planet, so far.

On the other hand, the Earth has its own natural satellite, the Moon.



Mars is the fourth planet orbiting the Sun. It is also known as "the red planet" due to the color of its surface, caused by the presence of iron oxide. Its atmosphere is carbon dioxide and it has two natural satellites: Phobos and Deimos.

Although for a long time Mars was considered an uninhabitable place, that perception has changed in recent decades, due to evidence suggesting the presence of large masses of frozen water under its surface.

Mars is, along with Venus, the other planet considered for terraforming, that is, for the creation of conditions that allow life.



It is the largest planet in the solar system and the second-largest celestial body in the system, after the Sun. Jupiter has a gaseous composition in which hydrogen and helium are the main components.

In its internal structure, Jupiter is speculated to contain liquid hydrogen and a rocky core.



Known for the seven rings that surround it, Saturn is also characterized by the presence of flattened poles produced by its low gravity and rapid rotational movement.

Saturn's atmosphere is composed of 96% hydrogen, while the remaining percentage is helium. It is speculated that in its internal composition there is rocky material covered by a layer of liquid hydrogen.

As a curious fact, the temperature of Saturn doubles that of the Sun, reaching 11726.85 °C; while the temperature of the Sun is 5505 °C.



Uranus is a gaseous planet composed of methane gas in greater proportion, followed by hydrogen and helium. It is the third planet in terms of size and the seventh with respect to its orbit from the Sun.

Uranus has a temperature of -224 °C, which makes it the planet with the coldest atmosphere in the solar system. In addition, it has a series of rings that surround it but unlike Saturn, they are not as visible and look as if they are orbiting the planet vertically.

However, this configuration of the rings of Uranus is an effect generated by its tilt, which makes its poles appear in the place that corresponds to the equator.



It is the farthest planet in the solar system and the fourth with respect to its size. Together with Jupiter and Uranus, they make up the group of gaseous planets, since their atmosphere is mainly composed of hydrogen, helium, and traces of hydrocarbons. Its characteristic blue color is due to methane, while its interior is rocky and icy.

Although it is a planet with very low temperatures (-218°C), the existence of an internal source of energy that makes Uranus generate heat is suggested.

Main characteristics of the planets






of translation



3,302× 10 23kg

58.7 days.

88 days



4.87 x 10 24kg

243 days

225 days.



5.97 x 10 24kg

24 hours.

365 days.



0.642 x 10 24kg .

1.30 days.

687 days.



1,899×10 27 kg.

9 a.m., 50 min.

4329 days.

24.79 m/s².


5.688 10 26 kg.

10:40 a.m.

10768 days.



8,686 x10 25 kg.

5:00 p.m., 2:00 p.m.

30685 days.



1,024×10 26 kg.

16h, 6min, 14s

60225 days



Key features of the solar system

The solar system has certain singularities that make the existence of the planets possible. This includes a series of conditions that allowed life on planet Earth or the existence of bodies of water on other celestial bodies. Some of those features are:

Its central star is the Sun

Every planetary system has one or more central stars. In our system, the central star is the Sun, and its amount of mass (1,989 × 1030 kg) represents 99% of all the mass that exists in the solar system. On the other hand, its gravitational force is so strong that it makes it possible for the planets to revolve around it (274 m/s²).

In the case of planet Earth, its distance from the Sun makes it possible for the sun's rays to penetrate its atmosphere and contribute to relevant processes for the generation of life, without causing damage.

Although the Sun is the most important star in our planetary system, it is not the only one. In the universe, there are almost three thousand stars with a series of planets orbiting around them. The Sun is just one of them.

It has several types of celestial bodies

In addition to the planets, in the solar system, there are also asteroids, comets, meteoroids, and natural satellites, such as the Moon or Io, one of Jupiter's moons.

has other planets

In addition to the eight planets that officially make up the solar system, there are other bodies considered less relevant, called minor planets. Pluto, Ceres, or Eris, among others, fall into this category.


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