Besides Planets and Moons, there are millions of smaller, rocky objects in the Solar System. These are called Asteroids.
Most Asteroids travel together in the Asteroid Belt, which is a wide, circular track of rocks, travelling at different speeds around the Sun.
Asteroids are Spare Parts that were left over when the Moons and Planets were formed in the Solar System.
Asteroids can be huge and can be anywhere between 10 km to 1,00 km wide.
Ceres is one of the biggest Asteroids. It is that big , that it is classed as a Dwarf Planet, one step down from the real thing.
As the Asteroids travel around the Sun, there is normally thousands of kilometers between them.
The Asteroid belt sits between Mars and Jupiter. It is like a dividing wall between the smaller inner planets and the big gassy giants in the outer planets.
Not all Asteroids live in the Belt. Some move around on their own. These Asteroids get pulled towards Moons and Planets by their stronger gravity. The small pieces of dust and rock that break off from the Asteroids are called Meteoroids.
Occasionally, an Asteroid will get bumped out of its belt and starts journeying through the Solar System. About once every 1,200 years they will collide with Earth.
An Asteroid narrowly missed Earth in 2013. It was 45 meters wide, and if it hit, scientists reckon it would have exploded with the force of hundreds of Atomic Bombs.
Some scientists believe that an Asteroid collided with Earth and wiped out the dinosaurs, over 65 million years ago.
There are nine really big Asteroids in the Asteroid Belt. They are named, Hygeia, Iris, Astrea, Pallas, Hebe, Metis, Flora, Juno and Vesta. Plus you have Ceres, the largest Asteroid in the Belt, which is so big its classed as a Dwarf Planet.
The Asteroid called Ida, could be bigger than London, and even has its own Moon, called Dactyl.
Most Meteoroids burn up when they get into the Earth’s atmosphere, but some large chunks manage to escape and hit the Earth’s surface from time to time. These are called Meteorites.
When a Meteorite burns up in the Earth’s atmosphere, it leaves a long streak of light in the sky. These streaks are called Meteors , but are also called shooting stars.
N.A.S.A launched the Dawn Mission in 2007, to send a probe to Vesta and Ceres. This allowed Dawn to orbit Vesta, photograph and map it, and then very gently fly to Ceres and orbit that.
As Asteroids orbit the Sun, they tumble and spin.
Because an Asteroid is a chunk of rock and metal, their shapes vary. Most are lumpy and shaped like gigantic potatoes.
Scientists believe that the Chicxulub crater in Mexico, is were a big Asteroid hit the Earth over 65 million years ago. It left a gaping crater 93 miles in diameter.
Scientists have separated Asteroids into three different categories. C-type or carbonaceous asteroids, S-type or siliceous asteroids and the M-type metallic asteroids.
Asteroids are also known as planetoids or minor planets.