When you fly two space craft around the moon for days on end, you may as well do something useful with them. So NASA created this beatifully colorful map of the moon, which shows how its mass varies over its surface.
The color indicates how much mass certain parts of our rocky companion has: red indicates more massive areas and blue corresponds to less mass. The image was generated from data acquired by two satellites, called Ebb and Flow, that together are known as GRAIL—Gravity Recovery and Interior Laboratory.
They use microwaves to measure the gravitational fried across the moon, which is easily done because of the lack of atmosphere. In fact, those conditions make this the most detailed gravity map of any body in our solar system. And, perhaps, the most colorful view of the moon we've ever seen. [NASA via New Scientist]
Image by Image: NASA/JPL-Caltech/MIT/GSFC