Asteroid vs Meteoroid
The earliest remnants of the formation of our solar system that was formed more than 4 billion years ago are asteroids and comets. These small bodies have played a key role in many fundamental processes that have shaped our planetary neighborhood. In space, a large rocky substance that orbits around the Sun is called an asteroid whereas much smaller particles are referred to as meteoroids. Once a meteoroid enters earth’s atmosphere and vaporizes, it becomes a shooting star or a meteor. However, if a small asteroid or a large meteoroid survives reentry, it lands upon the surface of the earth or the oceans and is then called a meteorite.
The source of formation of meteoroids is solar debris. Comets produce meteoroid streams when their icy nuclei passes near the Sun and releases dust particles. These meteoroid particles then continue to orbit the Sun much the same way as their parent comet. Collisions between asteroids have often resulted in the formation of meteoroids that have struck the surface of the Earth. As these meteoroids are easily available for scientific studies, we know that they are similar to asteroids in physical and chemical composition.
Asteroid is sometimes referred to as a small planet or planetoid. They are small bodies in orbit around the sun. They are smaller than planets but bigger than meteoroids. A meteoroid is the result of collisions between these asteroids. In simple words, a small pebble orbiting in outer space round the sun is a meteoroid. When it hits the earth’s atmosphere and begins to burn, it is a meteor. But if it is large enough to survive re-entry, it strikes the surface of the earth or the oceans and then it is called a meteorite.
The major difference between asteroids and meteoroids is of course their size. Some of the asteroids are large enough to be size of moon. In comparison, meteoroids are tiny pebbles but share the same physical and chemical composition.