NASA's twin Grail probes have revealed the surface of the moon in unprecedented detail, showing unbelievably deep cracks, craters and tectonic structures.
NASA's Grail mission to study the moon from crust to core has completed its main task ahead of schedule, gathering information about the internal structure and evolution of the moon in unprecedented detail.
A camera aboard one of NASA's twin Gravity Recovery And Interior Laboratory (GRAIL) lunar spacecraft has sent back footage of the far side of the moon.
NASA's twin GRAIL spacecraft will be placed into orbit around the moon over the New Year weekend, in preparation for their mission to study its composition and gravity field.