GROCE
gregladen | November 10, 2013He who lives by gravity shall die by gravity. That's what they say in the gravity biz, anyway. GROCE is the European "Gravity field and steady-state Ocean Circulation Explorer" Satellite which is a flying spacxe robot that has done some amazing research:
GOCE has a gradiometer with three accelerometers to measure gravity very accurately, to the level of 1 in 10^12th of Earth's gravity. In other words, if an X went to within Y meters of the detector, the detector could tell based on X's gravity. I'm not sure what X and Y are (I'm hoping someone who knows will fill in the blanks for us) but…