(music) (music) Cold. Grey. Lifeless. True. Dynamic. Complex. Surprising. Also true. Welcome to Earth's moon. For such a close neighbor, separated by a profound void, it mattered how we planned to visit. That's why NASA built LRO, the Lunar Reconnaissance Orbiter. Shortly after liftoff in June 2009, LRO began to transform our relationship. Because of LRO we now know the the Moon's topography--it's surface shape better than any other planet in the solar system, including Earth. Why? Because most of the Earth...is covered with this... But not the moon. There's more. LRO discovered the coldest measured places in the solar system measured in craters that never see sunlight. Evidence that the moon has been shrinking relatively recently and evidence of water ice at its surface. All by itself LRO has amassed a trove of discoveries. But LRO has not been to the moon all by itself. Working in concert with several companion missions, LRO made careful measurements as other vehicles intentionally blasted through the dusty exterior to probe this structure of the moons crust. What they learned, is that we've barely scratched the surface of all their is to discover. The moon remains a cypher, a mystery, a puzzle box. Home to one of the oldest large craters in the solar system, the Moon's surfaces is also a time machine. A witness to asteroid and comet impacts on Earth billions of years ago, the moon was pelted by ancient space rocks, too. Through examination of those craters, we travel into the past. The more we learn about the moon, the more we learn about the early solar system, and thus our own planet, Earth. The moon becomes the rediscovered history book of our solar system's great library, returning a precious volume we thought might have been lost to the sands of time. For all its silvery promised in our night sky, it's not easy to visit our nearest neighbor. But the chasm of vacuum in between still hasn't kept us away. Everyday the Lunar Reconnaissance Orbiter continues to probe vital questions, and amass essential data about a place close enough to light our nights, and illuminate new dreams of adventure future generations of explorers. For more information visit us on the web. (beeping)