|The Solar System is comprised of nine main planets, satellites and asteroids, each orbiting the sun. The sun provides the earth with heat and light that makes things grow on our very own planet earth and enable life to continue. The planets all spread out from the sun in this order from nearest to furthest: Mercury, Venus, Earth, Mars Jupiter, Saturn, Uranus, Neptune and Pluto. |
Planet Earth is actually 150 million km from the sun. Mars is often referred to as the 'Red Planet' and is thought to be uninhabited. Saturn is the only ringed planet and is also one of the largest with a total diameter of 120,660 km. Jupiter's diameter is 142,984 km.
The hottest planets are those closest to the sun and the coldest are the planets furthest from it. Mercury heats up to 427�C whereas Pluto may only ever be -236�C. The solar system was thought to have originally been created by dust and gas expelled from the sun during its formation. As this debris cooled, the planets formed. Occasionally debris falls from outer space, denting the earth's surface and in some cases, huge craters up to 1km in diameter are formed.
The sun is the earth's largest star and is just a part of the huge Milky Way Galaxy, which is in turn just one of the many other million galaxies in the universe. The diameter of the Milky Way is 100,000 light years and its mass is equal to 200 billion suns. It would take light 100,000 years at a rate of 299,460 km/hour to travel from one end of the Milky Way.