NASA's Gravity Recovery And Interior Laboratory (GRAIL) mission came to an end as planned yesterday when its two spacecraft de-orbited and crashed into the surface of the moon.
The first of the orbiters, Ebb, hit a predetermined mountain near the lunar north pole, with its twin, Flow, hitting nearby 30 seconds later.
Both were travelling at a speed of 1.7 kilometres per second.
The two craft were launched in September of 2011.
Following a successful mission mapping the gravity of the moon, the washing machine-sized spacecraft were nearly out of fuel.