GRAIL Maps the #Moon's Gravity
NASA's GRAIL mission mapped the Moon's gravity, revealing a shallow 40km crust and composition akin to Earth. This supports the theory that the Moon formed from Earth material post-collision 4.5 billion years ago. Post-mission, the GRAIL satellites were intentionally crashed into the Moon.
HD image at https://apod.nasa.gov/apod/ap130319.html
