What is the difference between an asteroid, a meteoroid and a comet? �

    Apart from the classes of asteroids, there are many flying objects similar to an asteroid. How would you identify what is and what isn't an asteroid?  On this subject there are many conflicting ideas.  Out of the five sources I found on this subject, most of them had completely different definitions as to what the differences were between these objects are.  In many of the sources, there was no clear distinction between asteroids and meteoroids, and the terms are used very loosely.  Using the best information I had, the definitions below summarize the differences.

�    A meteoroid is most commonly thought of as a small chunk of iron and rock that is smaller than an asteroid.  Meteoroids are thought to be particles from collisions between asteroids. When a meteoroid, or an asteroid, enters the Earth's atmosphere, it generates enormous heat and creates a blazing trail of �light called a meteor, or shooting star.  Usually the object burns up or explodes in Earth's atmosphere before it can touch the ground, but on a rare occasion it �will hit the surface of the planet.  When it hits the Earth's surface it is called a meteorite.  In general, meteorites are known for not having much of an impact, because of their size.

    Comets are huge bodies of burning gas and ice, usually larger than an asteroid. There are more than a hundred billion comets which travel in long orbits around the sun, up to twelve billion miles long.  The most well known comet is Halley's Comet, which only appears to Earth once every 77 years.  In general, a nucleus of a large comet can be as large as the size of the Earth or even greater, however Halley's is only twelve miles in diameter.  The tail of a comet always points away from the sun (which has to do with gravity).

    If a comet were to hit the Earth going at the same speed as an asteroid, it would do roughly about the same amount of damage. However a comet travels about 45 miles per hour faster than an asteroid. Comets are thought to be five times less likely to hit the earth than an asteroid: once every 500,000 years versus 100,000 years for an asteroid.