Clearly defeated in their attempt to destroy the galaxy with a laser, NASA sets its sights somewhat closer and tries to destroy the Moon:
Cooooool. Actually, while that is a laser, it's a bit too low power to do any damage to our friendly Moon. But it does have enough to help NASA track satellites! It's part of the Goddard Space Flight Center's Laser Ranging Facility in Maryland. We know the speed of light very accurately, so if you ping a satellite with a laser beam you can time the pulses and very accurately determine the satellite's position.
In this case, two beams were being used to track the position of NASA's Lunar Reconnaissance Orbiter, one of my favorite space missions of all time (to see why, check out this gallery of images I posted recently).
I used to work at Goddard, and I remember going to this facility once because it was a dark site from which I could try to spot a comet that happened to be passing us at the time. The laser was being used, and it was positively awe-inspiring and quite surreal to see it streaking up into the sky. And yes, they have to keep a careful eye out for airplanes and such flying past. While that beam isn't enough to melt a satellite, it's certainly enough to fry a pilot's eyes!
Which is why you don't want sharks equipped with these things. Really, that's just asking for trouble.
Image credit: NASA