Scientists have been reconstructing the history of the Moon by scouring its surface, mapping its mountains and craters, and probing its interior. Find out what the Moon's tumultuous past can tell us about our own planet's beginnings.
City lights broadcast our existence into the night of space. Imagine how the Earth will look to astronauts in a century's time or longer? These images are incredibly difficult to take from a spacecraft traveling along at almost 28,000 kilometers per hour.