Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Asteroid Belt Shepherding
Name: Tom
Status: other
Grade: other
Location: NV
Country: N/A
Date: N/A


Question:
Today at school my teacher asked us why does not the asteroid belt come crashing into the inner planets. Then she said that Jupiter's gravitational pull keeps it from moving into the inner planets. But I asked her why they do not crash into the inner planets when the asteroids are away from Jupiter and I was wondering if you knew?


Replies:
Tom,

Although Jupiter may exert some force on the objects in the asteroid belt, these asteroids maintain their orbits much in the same way that the planets do, their outward acceleration is opposed exactly by their inward acceleration - or put in another way, the asteroids and planets experience a centripetal force as the Sun's gravitational force pulls on it. The Sun's gravitational force pulls the bodies toward it, so that the result is that the bodies move in an orbit around the Sun.

Greg (Roberto Gregorius)


Dear Tom,

The main reason is that the asteroids,crowded as they are, leave a huge amount of empty space among them, so collisions with the planets are rare. But they do happen from time to time. The Earth was struck 50,000 years ago in northern

Arizona, for example.

Good question!

David H. Levy



Click here to return to the Astronomy Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory