What are the odds that two planets share the same orbit?

Question

I am thinking if there is a planet that has the same orbit and as Earth... it might make a good story....!!

Answer 1

Altough its very rare, i think that there might be other solar systems out there with 2 planets sharing the same orbit, but that would be very dangerous for both of them, if they where to hit each other it would be disaterous. They could even effect one another's rotation and ed up a planet with a moon, or a multi-planitary system.

There is proof of Binary star systems too, that means solar systems with 2 stars.

Answer 2

Assuming that you have a planet in orbit, there are five places where an object can be placed and maintain a stable orbit. These are called Lagrange points, after the mathematician Joseph-Louis Lagrange, who first proved their existence. L1 and L2 are in the same vicinity as the planet, one closer to the star and one farther. L3 is directly opposite the planet on the other side of the star. (Interesting idea. Two planets that would have similar conditions but unknown to each other until one race develops space travel. However, there's a problem.)

L1 and L2 are stable for about three weeks, so constant course corrections are needed. L3 is stable for about 150 years. So no planets could stay there.

L4 and L5 are stable so long as the mass in those points is at least 24.96% of the mass of the primary planet. These points are about 1/6 of the way ahead and behind the planet in its orbit. These are natural attractors. Our Earth is preceded and trailed by clumps of asteroids, called Trojans, at its L4 and L5 point. (Your characters would have to watch out for debris.)

People have long thought about putting a large space station at the L4 or L5 point. It wouldn't be entirely stable, as we'd have a hard time building an object with 25% of the mass of the Earth--at least initially. I guess in a few millenia, we might harvest metal from enough asteroids to make a planetoid-sized spacecraft. In the meantime, you'd have to correct the orbit manually.

L4 and L5 have long been the subject of science fiction, to the point that the starry-eyed space enthusiast pro-space organization was called the L-5 Society and filk songs such as Home, Home on LaGrange and similar travesties were sung at many a convention. The L-5 Society was founded in 1975, and in 1987 merged with the more hard-headed National Space Institute to form the National Space Society.

Answer 3

Not very high. It would be pretty hard to find a planet that share its orbit but it is possible.

Answer 4

a collision might make it possible. But God will not allow that. All those other planets were there to protect the earth. Its a perfect creation by the Almighty.Unless God has turned his back from us.

Answer 5

1-1. If Charon gets bumped up to planet status it will be a binary planet with Pluto.

Answer 6

Been done; John Norman had the Gor series.

Answer 7

There could be, but only at "Lagrange" points as indicated below.