A few minutes ago, NASA successfully destroyed two ailing spacecraft by smashing them into the Moon. You can see their crash trajectory in the video above. The two probes, Ebb and Flow, were orbiting the Moon to study its magnetic field and crust. But with fuel running low, NASA decided to fly them into a mountain near the Moon's north pole to prevent them from randomly crashing at the historic Apollo and Luna landing sites.
According to the Washington Post, the crashes went off with out a hitch. And the two probes revealed a lot about the Moon and other rocky bodies in our system:
The goal of the mission is to map the moon's gravitational field. To do this, NASA launched two washing-machine-size probes to orbit the moon in September 2011. After both craft achieved orbit on Jan. 1, they traveled around the moon in highly synchronized patterns at 3,600 miles per hour. The probes, named Ebb and Flow by elementary school students in Montana, could detect changes in the distance between one another down to a tenth of a micron - or half a strand of human hair. Their measurements have allowed scientists to create the highest quality gravitational field map of any celestial body, including Earth.
Two of the mission's key findings have to do with the nature of the moon's crust, specifically that it is much thinner than was previously believed and that "a couple of the large impact basins probably excavated the moon's mantle," Maria Zuber, the project's principal investigator, said during a news conference last week. Another "surprising discovery," she said, was how fractured the crust of the moon is because of impact.
"This is interesting because it tells us the role of impact bombardment on the evolution of an early planetary crust," Zuber said.
Read more in the Washington Post.