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) |