Meteoroids are chunks of rock and metal that orbit the Sun, occasionally encountering the Earth and forming meteors If they reach the ground, they become meteorites Although there is no specific upper size limit, these objects would be called asteroids if more than a few meters across Most are smaller, grading down into microscopic sizes
A solid object that is moving in interplanetary space, but is larger than a single molecule and smaller than an asteroid Meteoroids that are larger than 6 inches can fall to Earth as meteorites
A small body drifting through space If a meteoroid is pulled into a planet's or moons gravitational field, it is called a meteor if the meteor survives a trip through the atmosphere and lands, it is called a meteorite If meteorites are not burned up in the process of entering an atmosphere (or if there is no atmosphere), they may strike the surface and if large enough create a craters
The term used to describe a meteorite producing object while it is still outside the Earth's atmosphere Note that this term is reserved for those objects that can not be categorized as asteroids or comets