tunguska event

Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighborhood. Most asteroids are in what is called “the main belt” between Mars and Jupiter. The vast majority of near-Earth asteroids have come from the inner part of the main belt, where their orbits were altered by mutual collisions and by the gravitational influence of Jupiter and Mars.