Earth's mysterious large Moon is our nearest neighbor in space, dominating our clear night sky with its beguiling and bewitching cold golden glow. Earth's Moon is the only body beyond our planet that we have visited, leaving our footprints embedded in its alien dust. Despite its close proximity to our planet, our mysterious Moon has still managed to keep some ancient secrets from us very well. However, in October 2014, using data derived from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, a team of planetary scientists announced that they may have solved a lunar mystery almost as old as our Moon itself.
The twin spacecraft flew in an almost-circular orbit until the mission ended on December 17, 2012, when the probes were intentionally sent down to the lunar surface. NASA ultimately named the impact site in honor of the late astronaut Sally K. Ride, who was America's first woman in space and a member of the GRAIL mission team.
The rifts themselves are buried far, far down, deep beneath dark volcanic plains on the near-side of our Moon and have been spotted only in the gravity data provided by GRAIL. The lava-flooded rift valleys are not like anything seen anywhere else on the lunar surface--but some planetary scientists think that they may have, at one time, long ago, resembled rift zones on our own planet, Venus, and Mars. The new findings are published in the October 1, 2014 issue of the journal Nature.