Order of Galilean Moons

Dr. Jason Soderblom said in a September 10, 2015 Massachusetts Institute of Technology (MIT) Press Release that the evolution of lunar porosity can provide scientists with valuable clues to some of the most ancient life-supporting processes occurring in our Solar System. Dr. Soderblom is a planetary research scientist in MIT's Department of Earth, Atmospheric and Planetary Sciences in Cambridge, Massachusetts. With the GRAIL data, the astronomers were able to map the gravity field both in and around over 1,200 craters on the lunar far side. This region--the lunar highlands--is our Moon's most heavily cratered, and therefore oldest, terrain. Heavily cratered surfaces are older than smoother surfaces that are bereft of craters. This is because smooth surfaces indicate that more recent resurfacing has occurred, erasing the older scars of impact craters. Solving A Lunar Mystery Almost As Old As The Moon Itself! The rectangular pattern, with its straight sides and angular corners, weakens the theory that Procellarum is an old impact basin. This is because such a mighty impact would form a circular basin. Instead, the recent study indicates that processes occurring deep beneath the lunar surface dominated the formation of this unique region.