What Are The Differences Between An Asteroid, Comet, Meteoroid, Meteor and Meteorite? Asteroid: A relatively small, inactive, rocky body orbiting the Sun. Comet:  A relatively small, at times active, object whose ices can vaporize in sunlight forming an atmosphere (coma) of dust and gas and, sometimes, a tail of dust and/or gas. Meteoroid: A small … Continue reading Asteroid Fast Facts