A billion years ago, our Moon was closer to Earth than it is now. As a result, it appeared to be a much larger object in the sky. During that ancient era, if human beings had been around to witness such a sight, it would have been possible to see the entire Moon--not merely the one near side face that we see now. A billion years ago, it took our Moon only twenty days to orbit our planet, and Earth's own day was considerably shorter--only eighteen hours long. Stupendous, almost unimaginably enormous tides, that were more than a kilometer in height, would ebb and flow every few hours. However, things changed, as the lunar orbit around our primordial planet grew ever wider and wider. Annually, Earth's Moon moves about 1.6 inches farther out into space. Currently, the lunar rate of rotation, as well as the time it takes to circle our planet, are the same.
"For the smallest craters that we're looking at, we think we're starting to see where the Moon has gone through so much fracturing that it gets to a point where the porosity of the crust just stays at some constant level. You can keep impacting it and you'll hit regions where you'll increase porosity here and decrease it there, but on average it stays constant," Dr. Soderblom continued to explain to the press on September 10, 2015.
A Distant, Dusty Moon. Titan experiences changing seasons--just like Earth. In particular, Titan's seasons change around the equinox, when our Sun passes Titan's equator. At this time, huge clouds can form in tropical areas, resulting in violent methane storms. Cassini observed these ferocious methane storms during several of its flybys over Titan.