7/14/2002: Asteroid moon

Now there's something you don't see every day. An asteroid with a MOON.

This was on Astronomy pic of the day and comes from Galileo. It found these two on its way to Jupiter. The asteroid's name is Ida, the moon's name is Dactyl. The moon is only one mile across, while the asteroid is 36 miles long.

The best image of the moon:



"That's no moon"

Imagine if you were standing on it. You could easily see the rounded horizon. What I wonder is, if you jumped, would you jump OFF? The gravity on that thing must be tiny. And yet, the craters on it say that it's been hit by debris and it wasn't knocked out of orbit of its big brother, or so we have to assume.

I remember studying this asteroid last semester in my into to Astronomy class. The professor said that it may be a very common thing, but that we just don't have the time/resources/equipment to be looking for more of them.

Originally posted by Undertoad
And yet, the craters on it say that it's been hit by debris and it wasn't knocked out of orbit of its big brother, or so we have to assume.

Or maybe it was knocked <I>into</I> the orbit of the other. Or maybe they used to be part of a bigger asteroid, and a collision busted it into pieces, and these two pieces were at just the right distance for the smaller to begin orbiting.

Thats a beautiful image, anyone know where i can find a hires for my dtop?

Originally posted by sypher
Thats a beautiful image, anyone know where i can find a hires for my dtop?

there doesnt seem to be any larger images for you. here's the original post

http://antwrp.gsfc.nasa.gov/apod/ap020630.html