Why is the moon’s gravity so uneven?

A mission to investigate the Tycho Gravitational Anomaly 1 would make a good start for a book or movie. ;)

<i>gravitational fields resemble a bull’s-eye pattern: a center of strong, or positive, gravity surrounded by alternating rings of negative and positive gravity.</i><p>Negative gravity? Do tell....

On a related topic. I read this the other day:<p><a href="http://www.bbc.co.uk/news/science-environment-22736709" rel="nofollow">http://www.bbc.co.uk/news/science-environment-22736709</a><p>"The space rock, which is called 1998 QE2, is so large that it is orbited by its own moon."<p>The rock is 1.7 miles across, and is orbited by another 600 metre rock. I find it bizarre that a rock only 1.7 miles wide has enough gravity to be able to have its own "moon".

i was about to say, wouldn't an uneven mass distribution large enough to throw off probe trajectories also cause the moon to rotate off-axis until it readjusts its shape? then i remembered that the moon doesn't rotate, maybe precisely because of this!

Maybe an obvious answer, but why doesn't the Earth exhibit this? Or does it?

Yeah, it's so annoying. Everytime I go to the moon I remember how I hate that uneven gravity!