# A general gravitaion question!

1. Jul 8, 2010

We know that the sun attracts the earth and earth attracts the moon...but why do those two objects still have a huge distance? As in...why does the sun attract mars more than it attracts the earth or less than neptune or pluto? why arent all the planets as close to the sun as irons to a magnet??? hope u all are getting my point...if u have any idea about this, then do let me know....thanx....

2. Jul 8, 2010

### mathman

The essential point for all your questions is that the planets revolve around the sun and the moons revolve around the planets. The gravity pull is balanced by the tendency of all objects to continue in a straight line, which would have them travel away from the central object.

Mars is further away from the sun than the earth so the gravity of the sun is less for Mars. Your information is incorrect.

3. Jul 19, 2010

### rajatgl16

All the planets can be in same orbit if they are identical. But due to huge differences in their size, mass etc this happen

4. Jul 19, 2010

### mathman

They can in theory be in the same orbit with different masses, although their mutual attractions would tend to make the system unstable.

5. Jul 19, 2010

### khemist

If I had to guess I would say it has to do with their velocity more than the material or mass of the object.

6. Jul 20, 2010