Can Two Equal-Mass Planets Share a Satellite?

[Semaphia]

If you had a pair of celestial rotating in a circle, both of equal mass size. Would it be possible for the planets to have a shared satellite?

Thank you for reading, Alex

 

[DaveC426913]

Sure. Put the satellite into a large orbit around the centre of mass of the binary system. That's how trinary star systems (such as Centauri) work.

(But you were probably thinking of a satellite whose orbit switches between the two parents, weren't you?)

 

[Semaphia]

Would you expect the orbit of the satellite to have a less spherical orbit?

Thanks

 

[SpaceTiger]

Would you expect the orbit of the satellite to have a less spherical orbit?

You mean less circular? Even with one gravitating body, there's no reason a satellite should have to be in a circular orbit. It depends on the relative amounts of energy and angular momentum in the satellite. If the satellite started in a circular orbit about a single body, the addition of another gravitating body would certainly perturb that orbit. The amount it was perturbed would depend upon the relative separations of the satellite and the gravitating bodies.

 

[selfAdjoint]

There are weird Newtonian orbits with, for example five bodies, where one body "is dirven to infinity in a finite time". Sorry I don't have a link for this statement, I read the paper about 20 years ago.

 

[Semaphia]

Okay, thank you very much everyone. Alex

 

[Flatland]

wouldn't that be very onstable?