Our solar system is a collection of broad categories of planets. The four closest to the sun – Mercury, Venus, Earth and Mars — are the terrestrial planets.
- Mercury is the closest planet to the sun. It rotates slowly about twice for every three orbits it completes. Slightly larger than Earth’s moon, it is the smallest planet in the solar system. It has no moons, no rings, and an atmosphere so thin that scientists classify it as an exosphere.
- The second planet from the sun, Venus is slightly smaller than Earth. Because of its relative proximity to Earth, it is the largest planet seen in the night sky. it’s the thickest of the terrestrial planets, and it consists mostly of sulphuric acid and carbon dioxide.
- Earth, the third planet from the sun and the largest terrestrial planet, is the only planet known to host living beings and the only one known to have liquid water on its surface.
- Mars, the fourth planet from the sun, Mars, the Red Planet. The red colour of the surface comes from iron oxide or rust in the soil. The planet is colder than Earth, with surface temperatures ranging from -171 to 32 F (-113 to 0 C).
- The largest planet in our solar system is Jupiter. It is the first of the gas giant planets. Jupiter has 63 moons and a faint ring system.
- Saturn, the sixth planet from the sun, is also a gas giant, and it is the most impressive feature as seen from afar is an extensive and complex ring system. The interior of Saturn, like Jupiter, is made of mostly hydrogen and helium.
- The ice giant Uranus spins on an axis parallel to its orbit. With a diameter of 31,518 miles (50,723 kilometres) Uranus has a faint ring system and 27 moons in its orbit.
- The blue planet Neptune is the farthest one from the sun and, like Uranus, is a very cold place. Like all the outer planets, Neptune, like Uranus, has a diameter roughly four times that of Earth. Thirteen moons and a faint ring system orbit the planet.