The GRAIL mission determined the internal structure of the Moon in great detail for nine months during 2012. Armed with this the new information, GRAIL astronomers were able to redefine the sizes of the largest impact basins on the lunar surface.
The Kuiper Belt. Dark, distant, and cold, the Kuiper Belt is the remote domain of an icy multitude of comet nuclei, that orbit our Sun in a strange, fantastic, and fabulous dance. Here, in the alien deep freeze of our Solar System's outer suburbs, the ice dwarf planet Pluto and its quintet of moons dwell along with a cornucopia of others of their bizarre and frozen kind. This very distant region of our Star's domain is so far from our planet that astronomers are only now first beginning to explore it, thanks to the historic visit to the Pluto system by NASA's very successful and productive New Horizons spacecraft on July 14, 2015. New Horizons is now well on its way to discover more and more long-held secrets belonging to this distant, dimly lit domain of icy worldlets.
For those craters smaller than 30 kilometers in diameter, he discovered impacts both increased and decreased porosity in the upper layer of the lunar crust.