Do moons orbit moons?

[Manok101]

I was just curious because, every time I see a picture of Titan, Dione is always there in the background someplace nearby.

[paul mc c]

I may be wrong,but i think Plutos moon Charon has a small moon orbiting it!

[lw24]

Although physically possible, moons orbiting moons would be very unlikely, and there is no evidence of this happening in our Solar System.

Tidal forces from the parent planet would destabilise the orbit of the moon's moon, eventually dragging it out of it's orbit.

Clear Skies,

Luke

[Hypernova]

Would it not be any different to a planet orbiting a star with a moon? Same principal but different scales.

[661-pete]

Would it not be any different to a planet orbiting a star with a moon? Same principal but different scales.

That's what I would have thought. After all, we get an appreciable solar tide at Earth's orbit - hence the difference between spring tides and neap tides. But nonetheless, the Moon's orbit is barely affected by this at all - apart from the precession of its orbit, that is. Or is there anything else about the Sun perturbing the Moon's orbit?

On the other hand, the effect of the tidal drag of the Earth's oceans, on the Moon's orbit, is significant. It's gradually nudging the Moon into a bigger orbit, further from the Earth, and at the same time slowing down the Earth's rotation. Quite measurably. So there's no risk of the Moon crashing onto the Earth.

But whether the Moon could keep a satellite in a stable orbit indefinitely, I don't know. Spacecraft have orbited the Moon, of course, but they don't stay long.

I believe that for a moon in a retrograde orbit, like Neptune's Triton, the situation is reversed. Triton is being pulled into an ever closer orbit around Neptune, and will eventually break up and become part of the ring system.

[Simms]

I was just curious because, every time I see a picture of Titan, Dione is always there in the background someplace nearby.

That's a great question!!

And do those moons have moons orbiting them?