On Friday, NASA's unmanned Lunar Dust and Atmospheric Environment Explorer (LADEE) collided with the Moon's surface at about 3,600 miles per hour (roughly 5,800 kph). Whatever's left of the probe now rests on, around, and beneath the dark side of the moon.
This computer animation from NASA's Ames Research Center simulates LADEE's somewhat gruesome end:
The collision has been in the works for years. NASA scientists hope to find the crash site by using the Lunar Reconnaissance Orbiter (LRO), and perhaps get a better understanding of how the moon's surface responds to collisions from spacecraft. (Better than spacecraft respond to collisions with the moon's surface, I'd imagine.)
While scientists had (fruitlessly) hoped that data from the LADEE probe would immediately give us a better sense of what produced that weird aurora borealis effect astronauts noticed during the manned moon landings of the late 1960s and early 1970s, that part of the mission wasn't successful. But LADEE still provided voluminous data about moon dust, the minimal lunar atmosphere, and—in a dry run for future missions—the practical application of laser beams as a communications technology.
NASA scientists hope to take what they have learned from LADEE and apply it to next year's Pluto mission, which—given Pluto's icy surface and the possibility of damaging or contaminating same—will not end with a planned collision.