Asteroids are primordial material left over from the formation of the Solar System. They are scattered throughout it: some pass close to the Sun, and others are found out beyond the orbit of Neptune. A vast majority have been collected by Jupiter’s gravity into a belt between it and Mars – an area known as the Main Belt. As it turns out, we have been discovering thousands of asteroids that do not belong to the Main Belt, but instead pass near Earth’s orbit – nearly 9,000 to date, with almost a thousand more are discovered every year.