Spyder 3 Arctic seen from Space! For the Space Station flash, the San Antonio astronomers used a one-watt laser and a gang of two mercury-argon arc lamps. Both were clearly visible from my vantage point. Don Pettit - Astronaut International Space Station
After gazing up at the moon for thousands of years, we're still not exactly sure how it came to be. Here's a brief rundown of the most prominent theories scientists have come up with to explain the moon's origin.