Look up at the sky this evening. If you can see the moon, its characteristics are probably very familiar to you. The craters and other shadows never seem to change, but NASA research is telling us the moon wasn't always full of mountains and valleys.
Thanks to its Lunar Reconnaissance Orbiter (LRO), NASA has captured some of the most detailed images of the moon, which has led the agency to better understand of why it looks they way it does today. In honor of LRO being in orbit 1,000 days, NASA developed two videos about the moon's development from data made possible by the orbiter's mission.
Watch the simulation of its billions of years of bombardment, which have given the moon the pocked characteristics we know of today:
Here's a more in-depth, narrated tour of the moon:
NASA explains in a press release that the most common school of thought is the moon started as a ball of magma formed after a planet-sized object hit Earth. Right as the moon was cooling and its crust forming, the moon itself was hit, creating its South Pole-Aitken Basin, which NASA explains is one of the two largest proven impact basins in the solar system.
The moon's beating didn't stop there. After magma seeped up through cracks in a series of volcanic activity and began to cool again, smaller objects battered it, eventually leaving us with the pockmarked, man-in-the-moon image.
LRO launched aboard an Atlas V rocket from Cape Canaveral, Fla., on June 18, 2009. Since then it has been collecting new measurements and an "unprecedented" view of the moon's surface.