Hi

If anyone can help me, it would be appreciated.

I would like to know 3 things.

1 - why do planets orbit all on the same plane?

2 - why do they all orbit in the same direction?

3 - is this the same with all stars and their planets, or just our own solar system?

These answers would be nice asap, they are quite urgent for a project.

Thanks

Have you tried Google?

planetary orbits - Google Search (http://www.google.com/search?hl=en&q=planetary+orbits)

Try Google or Yahoo for those answers

1) when the solar system formed from a dusty sphere around the sun, the dust particles were all orbiting in different directions. However, the net rotation was not zero, as there were a few more particles rotating one way than another way. When the gravity from the star and the dust acts on this, as angular momentum is conserved, the rotations speed up. The particles spinning in the same direction as the net rotation will be feeling a centripetal force which stops them from collapsing as much as the ones that aren't. This leaves a flat disc of particles that form the planets.

2) same reason as above.

3) Yes, the only things that might orbit the wrong way might be a captured comet or a planet with it's orbit altered by collision or something like that.