Difference Between Asteroid and Comet
Asteroid	Comet
Asteroids have an elliptical orbit	Comets have an eccentric orbit.
It is made of metals and rocks	Made of rocks, hydrocarbons, and ice
Do not produce a coma or tail atmosphere	Thin, temporary atmospheric tail when close to the Sun.
The orbital period is 1 to 100 years	The orbital periods are 75 to more than 100,000 years.
1 to larger than 100 kilometers in size	1 to 10 kilometer in size (nucleus only)