The Moon was hot at the beginning of its life. The most accepted theory—proved by simulations and analysis of its surface materials—is that it formed after a massive collision of a Mars-sized object with Earth, around 4.5 billion years ago. The material ejected in the impact accreted to form the Moon. After that, the lunar surface suffered a period of massive bombardment of asteroids and meteors, which combined with the decay of radioactive elements, kept it hot for a long while.
So long, in fact, that it’s still probably cooling down today.
But how much has it shrunk? Using data taken by the LRO, they believe the distance between the moon’s center and its surface shrank about 300 feet in the last one billion years.
NOOOO!! THE MOON IS SHRINKING?!?!??!!
… flipping ahmazing picture though..
