deformation of orbits

[jake_at]

hey, i was just wondering some stuff about the orbit of planets in our solar system. is when passing jupiter, for example, the orbit of mars deformed, turned into an ellipse? if so, does this mean that mars is getting closer and closer to jupiter, or is there something that will keep mars from eventually being pulled right into jupiter?

:) J.

[chroot]

Mars's orbit is already an ellipse, as are all the planets' orbits. Jupiter DOES deform Mars's orbit when they are nearest each other. In fact, all the planets deform each others' orbits, but not always detectably so. For example, Mercury does not have much of an effect on Pluto, but Neptune does. (That's how Pluto was discovered.)

In general, Jupiter tugs on Mars some on one side of the Sun, and again on the other side some time later. Since the tugs are not always in the same direction, they average out over time.

- Warren

[Thallium]

But why do they deform eachother's orbits? Is it the magnetic field?

[selfAdjoint]

The varying gravity strength as the planets pass closer or farther away from each other.

[chroot]

Originally posted by Thallium
But why do they deform eachother's orbits? Is it the magnetic field?
The planets are massive, and thus exert gravitational influence on each other.

- Warren

[Labguy]

http://csep10.phys.utk.edu/astr161/lect/history/kepler.html

[Thallium]

Lovely! Three answers[:)] Thanks for the link!