Principal Characteristics of the Planets

Mercury

Mercury is the smallest planet and closest to the Sun, with a highly elliptical orbit.
It has no moons and no significant atmosphere, primarily because of its proximity to the Sun and small size.
Due to lack of atmosphere, its temperature varies greatly, from extremely hot to extremely cold.
Its surface is heavily cratered, similar to Earth’s moon.

Venus is the second planet from the Sun, similar in size to Earth but with a thick, toxic atmosphere largely composed of sulfuric acid and carbon dioxide.
It has no natural moons and its surface is hidden by thick clouds, although radar mapping has shown it to be volcanic and mountainous.
Despite being further from the Sun than Mercury, it is the hottest planet due to its greenhouse effect.
Venus has a very slow rotation, taking 243 Earth days to complete one Venusian day.

Earth is the third planet from the Sun, the largest of the four terrestrial planets, and the only celestial body known to harbour life.
It has a strong magnetic field that protects it from the solar wind, making life possible.
Earth has one moon, which stabilises the planet’s tilt and therefore climate.
Approximately 70% of Earth’s surface is covered in water.

Mars, often called the Red Planet because of its reddish appearance, is the fourth planet from the Sun.
It has a thin atmosphere of mostly carbon dioxide, and it’s much colder than Earth due to its distance from the Sun.
Mars is home to the tallest volcano and the deepest canyon in the solar system.
It has two small moons, Phobos and Deimos.

Jupiter is the fifth planet from the Sun and the largest planet in the Solar System.
It’s a gas giant composed mainly of hydrogen and helium, similar to the Sun.
Its strong magnetic field helps to create spectacular polar auroras.
It has a system of rings and a large number of moons, including Ganymede, the largest moon in the solar system.

Saturn, the sixth planet from the Sun, is a gas giant renowned for its prominent ring system.
It has a thick atmosphere mostly composed of hydrogen and helium.
Saturn is the least dense planet in our Solar System, it could float on water if there was a basin large enough.
It has a large number of moons, the largest being Titan, which is larger than the planet Mercury.

Uranus is a gas giant and the seventh planet from the Sun. Its blue colour is due to methane in the atmosphere absorbing red light.
It has a complex system of thin, dark rings and more than two dozen moons.
Uranus is the only planet that rotates on its side, perhaps due to a collision with a large body in the past.
It’s a very cold planet, with temperatures reaching as low as -224 degrees Celsius.

Neptune is the eighth and farthest planet from the Sun, a gas giant with a deep blue colour.
It has strong winds and large storms, including the Great Dark Spot that is similar to Jupiter’s Great Red Spot.
Its atmosphere is primarily composed of hydrogen, helium, and methane, which gives it a deep blue colour.
Neptune has a faint ring system and 14 known moons, the largest of which is Triton.