Why Don"t Moons Have Their Own Satellites?

Have you ever wondered why moons don"t have other moon"s in orbit around them? The question is rather common, but the answer is rather complex -- especially when you initially attempt to visualize the mechanics of such a system.

Technically speaking, everything is in orbit around something else. The Earth, Sun, and all the planets orbit around the center of mass of the solar system. More generally, Earth orbits the Sun; the Moon orbits the Earth; our entire solar system orbits around Sagittarius A* (the supermassive black hole in the center of our galaxy); our galaxy completes one full rotation every 230 million years (interesting aside, Sagittarius A* might have 10,000 additional black holes in orbit around it).

And in theory, it"s possible that our Moon once had a satellite of its own; however, for such a body to remain in orbit, it would need to have to very specific characteristics for its size, mass, speed, and orbital distance. It would be difficult for an orbiting body to fit these exact parameters, but it is possible. As such, it is appropriate to ask why moons don’t have their own moons. After all, we’ve observed large asteroids with satellites. Why then don"t moons have satellites of their own?

To find out, see:
http://www.fromquarkstoquasars.com/why-dont-moons-have-their-own-satellites/

Image source:
http://grin.hq.nasa.gov/ABSTRACTS/GPN-2001-000009.html