NASA is set to crash a pair of washing machine-sized probes into the moon on Monday, after months spent examining and gathering data about the moon's surface, reports AFP. Though Ebb and Flow will hit the surface at a speedy 3,760mph, they'll be out of fuel when they do so, so no "big explosion" is expected, says the project's lead. But if there is one, we'll miss it: That north pole region where they'll hit will be in shadow at the time, preventing NASA from photographing it.
Ebb and Flow have been circling the moon since Jan. 1, at a range of 14 to 34 miles above the surface. But as the probes take their last breath, they'll conduct one final experiment: They'll fire their main engines until all the fuel is spent, allowing NASA to calculate their fuel levels and better understand future fuel needs. "Our lunar twins may be in the twilight of their operational lives, but one thing is for sure. They are going down swinging," adds the project's head. (Read more moon stories.)