The planets can be divided into two large groups: the inner planets, also called terrestrial planets, which are Mercury, Venus, Earth and Mars; and the outer planets, also called giant planets, which are Jupiter, Saturn, Uranus and Neptune. MERCURY has a cratered surface, very similar to that of the Moon. It is the closest to the sun and the Earth could contain it 18 times, because it is the smallest planet in the solar system. It has temperatures that not even the most inhospitable terrestrial desert could reach, up to 450° during the day and even -180° at night. VENUS is about the same size as the Earth. If you pay close attention, you will see it shine like the first star of the evening, shortly after sunset. It is the brightest object in the night sky after the moon, thanks to the dense layer of clouds in its atmosphere, which reflects sunlight and makes the surface of the planet even hotter than that of Mercury. Its air is unbreathable. ???? Of all the planets known so far, EARTH is the only one that is known with certainty to be able to host life. This is also thanks to the oceans that cover 7 tenths of its surface. Its atmosphere is rich in oxygen that allows us to breathe and the fact that it is at the right distance from the sun makes its temperature optimal for life. Even if we don't notice it, the Earth rotates on itself and it takes 24 hours for it to complete a full rotation around itself, that is, a whole day. While it rotates on itself, the Earth also orbits around the sun. To complete a full rotation around the sun, the Earth takes 365 days, that is, 1 year. The Moon revolves around the Earth and never leaves it. The Sun, on the other hand, is our star: it is very hot and gives us light and heat. MARS is made up of ferrous minerals that give it a reddish color. For this reason, it is also called "the red planet". It once had water, as evidenced by the deep channels visible on its surface, but today it is an arid, desert and inhospitable place, with temperatures up to 250°, with an atmosphere based on carbon dioxide and violent sandstorms raised by the winds. Given its proximity to Earth, man is planning to reach it with space missions. In the meantime, NASA has sent Curiosity to Mars, a little robot that has been roaming the red planet since 2012, sending us wonderful glimpses of its landscape. Beyond Mars, almost separating the inner planets from the outer ones, there are millions of pieces of rock: they are asteroids that form the asteroid belt and they too orbit around the Sun. JUPITER is the largest of all the planets. It is an enormous ball of gas and does not have a solid surface, but is composed of a very cold mixture of hydrogen and helium, like the gas used to inflate balloons. Despite being gigantic, it spins on itself very quickly: 1 day on Jupiter, in fact, lasts less than 10 hours. Just think that Jupiter could swallow 1300 Earths. ???? Then there is SATURN, which despite being over 700 times larger than Earth, weighs just 95 times more than our planet. Saturn has winds that reach 1800 km per hour. It is best known for the thousands of rings of rock and ice that surround it. Saturn also has many moons, and 72 are known so far. URANUS is so far from the sun that it takes 84 years to complete an orbit around it. It is said to be made of an icy mixture of water, methane and ammonia, while its core is said to be rocky. NEPTUNE is little known, because it is even more distant. All we know about Neptune is that it is as big as 57 Earths, is gaseous with a rocky core and orbits the sun in about 165 Earth years. AND PLUTO? Far away, very far away, it is neither one of the inner nor the outer planets. It is smaller than our Moon and it also has a Moon, namely Charon, of similar dimensions to its own. For this reason, many scholars consider Pluto and Charon to be a double system of planets. Due to its strange characteristics, in 2006 it was downgraded from a planet to a dwarf planet and it seems that it did not form together with the other planets in the solar system. It even seems that it was captured at a later time by their gravity. ???????? Follow us on Facebook! / pasticciotti.it and on Instagram: i_pasticciotti_it MUSIC: Fanfare for Space by Kevin MacLeod is a song licensed under a Creative Commons Attribution 4.0 license. https://creativecommons.org/licenses/... Source: http://incompetech.com/music/royalty-... Artist: http://incompetech.com/