the solar system in brief

For 4.6 billion years, the Sun has been home to an entire ecosystem of planets and other celestial bodies that make up the Solar System. Here is some information about its main representatives.

As inhabitants of the earth, we are part of the solar system. Consisting of several planets, moons and other celestial bodies, it was born 4.6 billion years ago after the solar nebula gave birth to our star, the Sun. So here is a short journey through space to discover our nearest neighbours.

Definition of the solar system

Located in the Orion arm of our galaxy, the Milky Way, the Solar System consists of a collection of planets, moons, asteroids, comets and other celestial bodies that orbit our star, the Sun. 4.6 billion years old, it orbits the center of the galaxy at an approximate speed of 830,000 km/h and completes a complete rotation, meaning a full rotation of the latter in about 230 million years according to NASA data.

The artist’s impression of the solar system and its eight planets with the visible section of the Milky Way in the background SCIEPRO / GETTY_IMAGES

The composition of the solar system

Still according to data from the US space agency, our solar system consists ofa star, eight planets, five dwarf planets (Pluto, like, haumea, Ceres, Eris), more than 200 moons, more than 1 million asteroids and at least 3700 comets. Figures which, for some, could be made to develop as the discoveries of astronomers.


The planet closest to the Sun,Mercury is also one of the smallest in the system. Like Venus, Earth or Mars, it is a telluric planet. Understand here that it is mainly composed of metals and stones. Due to its proximity to the Sun, between 46 and 70 million kilometers, it is the planet that makes the fastest lap in just 89 days and makes a complete turn on itself in 59 days. Devoid of moons and atmosphere, it is a planet on which the temperature variations are extreme. Against the sun, its the surface temperature can reach 427°C when, in some of these polar craters, where light never penetrates, the temperature can drop to -183°C.

Artist’s impression of Mercury, the smallest planet in the solar system SCIEPRO / GETTY_IMAGES


The second planet in order of distance from the Sun, which it orbits in about 224 days, Venus is in its form, very similar to Earth, so much so that it is often considered like his twin sister. In fact, its radius, mass, and volume are roughly the same as our planet. But the comparison stops there. The various probes that have been sent flyby or directly onto its rocky base have revealed several things. So we know that his the atmosphere is more than 90% CO2 which has the consequence of generating a greenhouse effect so significant that its The average surface temperature reaches 462°C, regardless of where you are. Finally its surface pressure is about 93 times greater than ours. It is as if you were constantly under water at a depth of almost 900 meters.

Artist’s impression of Venus, where the average surface temperature is 462°C SCIEPRO / GETTY_IMAGES

the earth

Is it really necessary to present it? Shortly said, thatthe earth is a terrestrial planetthe only one where life as we know it has evolved thanks to the presence of a liquid that we currently do not find anywhere else: water. About 71% of its surface is covered by it hence his nickname”blue Planet“. Of the four planets closest to the Sun, it is the largest. It has only one natural satellite that we can observe every night: the Moon. The average temperature there is 15°C.

the earth Matthias Kulka / GETTY_IMAGES


If Earth is nicknamed “The Blue Planet”, March is she, the “red planet”. It takes its nickname from the oxidized iron minerals in its soil, giving it this instantly recognizable hue. Mars is accompanied in its orbit by two moons: Deimos and Phobos and perform one rotation around the sun in 687 days. Smaller than Earth, Mars not having the capacity to hold life, as we know it. But the readings made by different rovers on Earth’s soil trying to determine whether life has been able to develop there, or whether it will be able to develop there in the future. In particular, it is the planet that Elon Musk is targeting to establish a future colony there.

Artist’s impression of Mars, the Red Planet and possibly the home of the first extraterrestrial colony SCIEPRO / GETTY_IMAGES


Jupiter is by far the largest planet in the entire solar system. It is so big that we could align the Earth 11 times to its equator. Very easily recognizable by its size, it is also thanks to its red spot, which is none other than a storm that has been raging for a century. By comparison, this giant storm is twice the size of Earth. If he just needs it 10 hours to perform a rotation on itself, it needs its equivalent 12 Earth years to complete one orbit around the Sun. Its atmosphere consists mainly of hydrogen and helium. No less than 75 moons orbit the gas giant, of which the best known are: Europe, In IslandGalileo and Callisto. They are also in the view of scientists to try to discover favorable conditions for the development of life.

Representation of Jupiter, the largest planet in the solar system. The storm that rages there is here on its left side. SCIEPRO / GETTY_IMAGES


Very easily recognizable thanks to its rings, Saturn is the second largest planet in the solar system after Jupiter. It is a gas giant for whom the days are long a littlemore than 10 hours but which completes a complete course around the Sun in 29 years. Around it are seven rings composed mainly of asteroids, as well as at least 53 moons, the largest of which is Titan. If Saturn, because of its gaseous state is and never will be habitable by humansTitan as well as other moons like Enceladus or Mimas are studied because they could contain oceans of salt water beneath their surface. Nothing is certain yet, and future readings, NASA in particular, we will certainly learn more about this planet and its moons.

Representation of Saturn and its seven rings, including at least 53 moons SCIEPRO / GETTY_IMAGES


The seventh planet of the solar system, Uranus was the first to be discovered by a telescope. We owe this feat William Herschelin 1781 who had at first mistaken it for a star. Unlike its last two sisters, it is not a gas giant, but is rather considered one ice giant. In fact, it is composed of ice of water, ammonia and methane. It is the only planet in the solar system to have one slope of more than 90°C, as if our planet tilted and the North Pole suddenly turned towards our star. On Uranus, days last 17 hours, while years last 84 years.

Representation of Uranus and its rings, we can note here its tilt axis SCIEPRO / GETTY_IMAGES


The farthest planet from the Sun in the solar system, Neptune is more than 4.5 billion kilometers from our star. Like Uranus, it is one ice giant. Accompanied by her 14 moons, she performs a rotation on itself in 16 hours but because of its distance from the Sun it is completes a cycle of 165 years. Thus, in 2011 it completed its first orbit since its discovery in 1846. It is the last planet in the solar system since Pluto was demoted to the rank of dwarf planet in 2006, following a vote by the International Astronomical Union (IAU). Neptune could not be studied thoroughly. Only the probe Voyager 2 currently flown over it, in 1989. The planet was headed for the interstellar void.

Representation of Neptune, the eighth and last planet in the solar system. It takes 165 years to make a complete revolution around the Sun. SCIEPRO / GETTY_IMAGES

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