How did asteroids form and what is the difference between an asteroid and a comet?
Hi, I am a 2nd grader doing a science project on asteroids. Can you please tell me how asteroids are formed and what is the difference between an asteroid and a comet.
Asteroids formed from small pieces of rock and metal just like the rest of the solar system. Small particles run into each other, and if they don't hit too hard, they'll stay together because their gravity pulls them together. The reason why the asteroids didn't continue to grow into a planet like all the rest of the planets is that they are too close to Jupiter. Jupiter's gravity "stirs them up" and makes them go so fast that when they run into each other, they usually bounce off or break apart instead of sticking together.
Comets formed farther away from the Sun. They're made of ice, which would melt if it was as close to the Sun as the asteroids. In fact, when comets leave the outer parts of the solar system to travel close to the Sun, they do melt, and the ice that was turned to water vapor forms the long tail that we see in the sky. After a few trips into the inner solar system, the comet will melt so much that it breaks into little pieces!
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
- Are the asteroids the remains of a planet which broke apart?
- Why are the compositions of comets and asteroids different?
- Can the theory of formation of the solar system explain all the observables?
- Are Kuiper Belt Objects asteroids? Are large Kuiper Belt Objects planets?
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 61936 times since September 18, 2002.
Last modified: September 20, 2002 1:30:24 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)