I’m not asking if it does, of course. We’d have noticed by now. But from the little I’ve read a moon would need a stable orbit to “support” a submoon. Does ours qualify? And would it affect Earth?
A real scientist will be along soon to correct me, but probably not. The three-body-problem is not just a TV show. Here’s Neil deGrasse Tyson explaining it.
Huh, All this time I assumed (for some reason) that the “Three Body Problem” was something about swapping minds.
In order for the system to be stable, either:
The submoon has to be really tiny, and really close to the moon.
Or:
The earth has to be really large, and really far away from the moon and submoon.
As I understand it, there’s a few fairly stable orbits around the Moon; it’s where we put probes/satellites.
However they can’t be very high or the Earth will perturb the orbit, and most low orbits are unstable because the Moon is very “lumpy” with an uneven gravitational field. I expect that you therefore could have a natural “submoon” orbit Luna just as our probes do; but probably not a long-lasting one.
But there are ghost moons.
Depends what you classify as a moon. I think it hasn’t been proven that the Apollo 11 ascent module ever crashed back into the moon and could still be orbiting since 1969. Modeling of the orbit strongly indicates the orbit did decay and the module did return to the moon’s surface. On that basis earth has thousands of other moons now, and for some time to come.
As mentioned above, it is possible for a moon to have the right conditions to have a stable submoon, but not our moon because of the mascons.
Technically, a sub-moon would be part of a four body problem. The Sun’s gravity is strong enough to play a notable part of the equations. While going from 2 bodies to 3 is the killer step in calculating paths, going from 3 to 4 just piles on the chaos in the equations.
previous discussion: