This graphic highlights locations on the moon NASA considers "lunar heritage sites" and the path NASA's Gravity Recovery and Interior Laboratory spacecraft will take on their final flight. Image released Dec. 13, 2012.
Two NASA moon probes will end their gravity-mapping mission in spectacular fashion Monday (Dec. 17), crashing intentionally into a cliff near the lunar north pole.
The twin Grail spacecraft, known as Ebb and Flow, will slam into the raised rim of a moon crater at 5:28 p.m. EST (2258 GMT) Monday, mission team members said today (Dec. 13). The probes will impact about 20 seconds apart, with each traveling at 3,760 mph (6,050 kph) or so.
For the rest of the story: http://www.livescience.com/25562-nasa-grail-spacecraft-moon-crash.html