Question: why do asteroids revolve around the sun in an elliptical orbit

Jacquie Oliwa answered on 13 Jul 2017:

Hi Delrey,
Asteroids move because of gravity. From Newton’s laws of motion, if something is moving, it will continue to do so until something (e.g. air resistance, friction, brick wall) stops it moving. In space there is no air, so the asteroids first get their initial push from something exploding or dust clouds sticking together and then nothing stops them. The only thing that affects them is the sun’s gravitational pull, which pulls on them so they revolve in orbits-like the planets do-around the sun.

Why elliptical? This happens because objects in space like asteroids and planets have a velocity in the direction perpendicular to the force of the Sun’s pull. If the Sun weren’t there, they would travel in a straight line. But the gravity of the Sun alters their course, causing them to travel around the Sun, in a shape very near to a circle (an ellipse) because the opposing forces are not perfectly equal.

Hope that answers your question?
Best,
Jacquie