Planets and Moons ID: 10948

Shrinking, Growing Moon

Story by William Steigerwald Released on April 5, 2012

Ever since getting whacked by asteroids and cooked by heat radiating from unstable elements during its violent formation, the moon has cooled. Many things shrink as they cool and the moon is no exception. But tiny valleys discovered in new images from NASA's Lunar Reconnaissance Orbiter (LRO) indicate that the forces causing the moon to shrink were accompanied in some places by other forces acting to pull it apart. This tectonic tug-of-war taking place on the supposedly inert lunar surface surprised scientists. Not only that, it suggests the moon never completely melted in its early stages of evolution—unlike Earth and the other rocky planets—and instead was covered by an expansive ocean of molten rock. Watch the videos below to see evidence of these lunar valleys, called graben, and to learn more about the moon's fascinating geologic past.

The largest of the lunar valleys, located in the highlands of the moon's far side, measures about 1,640 feet wide (marked) and 66 feet deep.

For More Information

NASA.gov

Story Credits

Video Editor:
Dan Gallagher (USRA)

Interviewee:
Tom Watters (Smithsonian/Air and Space)

Producer:
Dan Gallagher (USRA)

Lead Scientists:
Tom Watters (Smithsonian/Air and Space)
Richard Vondrak (NASA/GSFC)

Videographer:
Rob Andreoli (Advocates in Manpower Management, Inc.)

Lead Writer:
William Steigerwald (NASA/GSFC)

Please give credit for this item to:
NASA's Goddard Space Flight Center

Short URL to share this page:
https://svs.gsfc.nasa.gov/10948

Keywords:
NASA Science >> Planets and Moons
SVS >> App