Solar System (or planets) Key Facts and properties.
- There are 8 Planets in orbit around the Sun.
- Mercury is the closest, and Neptune is the outermost Planet in the Solar System.
- The further a Planet is from the Sun, the slower it travels, and the more time it takes to complete an orbit.
- The further the Planet is from the Sun, the lower its average surface temperature. Except for Venus, where 97% Carbondioxide in the atmosphere causes severe greenhouse effect, and makes Venus the hottest Planet in the Solar System.
- Mercury is the smallest, and Jupiter is the largest Planet in the Solar System.
- The axis of rotation of Earth is tilted by 23.5°, and the axis of rotation of Uranus is tilted at more than 90°.