Moon around Kuiper Belt Object

UncleJosh writes "Today's NY Times (free reg rq'd) has a story about the first Kuiper Belt Object (KBO) with a moon, 1998 WW31. The hubble telescope has been used to get information about the size and orbit of the moon. Seems lots of things have moons. Coming more than 20 years after the discovery of Pluto's moon Charon the discovery of a KBO with a moon also follows the discovery of asteroid Ida's moon Dactyl and other moons of asteriods."

Comments

Hubble space picture of 1998 WW31

[Anonymous Coward]

Posted on the Hubble site 7 days ago when this was news.

This IS surprising (physics)

[Spamalamadingdong]

Two boides are attrackted while spinning in orbit around another, larger body. They start to co-orbit. That's physics people.

Two bodies approach each other from "infinity", and somehow they lose enough energy and/or angular momentum in their encounter to wind up in mutual orbit. How's that? What's the mechanism for dissipating energy, or transferring angular momentum from motion of the bodies around their center of mass to spin of the bodies themselves (Earth and Luna are doing this in reverse, but very slowly; far too slowly to capture anything).

Since you've set yourself up as the physics expert, perhaps you'd like to explain that to all of us. You'll probably get a publishable paper out of it too, so it's not like it isn't worth the work.