[oozcitak]

Also see GRACE (launched in 2002), which measures the time variation in Earth's gravity field, albeit with a much lower spatial resolution than GOCE:

http://en.wikipedia.org/wiki/Gravity_Recovery_and_Climate_Ex...

[mturmon]

And GRAIL, to be launched September of this year, which will do the same thing for the interior of the Moon:

http://moon.mit.edu/