Avian, what's up with this new Earthlike planet?

[Bob Lentil]

Originally posted by Avian
The masses of the planets do not significantly determine how fast they go around the sun. If Jupiter were in the exact place where Mercury is, it would take the same time to go aorund the sun as Mercury - about 88 earth days. If Mercury, a tiny pebble compared to Jupiter, were placed here Juptier is, it would take the same time as Jupiter to go around the sun - about 12 earth years. The gravitational force exterted by the mass of the planet on the sun has little effect on their overall motion on the sun. The sun's massive gravity when compared to the planets is the overwhelming dominating factor here.

Good point. I'm always forgetting how big the sun is.

Originally posted by Avian

The acceleration that an object experiences due to gravity (or any other force) is indepenant of mass of the object.

Here's where I disagree with you. The acceleration an object experiences due to a force is not independent of its mass. According to Newton's second law, Acceleration = Force/Mass. If I exert a force on a basketball, it's going to accelerate a whole lot faster than if I exert the same force on the sun.