The Lunar and Planetary Science Conference announced on 2015-03-16 that a 198 km wide crater has been found on the moon using the GRAIL spacecraft that uses gravitational field mapping. This enabled the discovery of craters below the surface. It's been named the Earhart crater. Nice gravitational photos can be found in the links.
(Score: 2) by tathra on Friday March 20 2015, @10:27PM
its the absolute value of the mass that's missing due to the fact that there's a crater/hole there (since the mass is missing we give it a negative, then use the absolute value since there's no such thing as negative mass).