Shrinking, Growing Moon

  • Released Thursday, April 5, 2012
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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.

Left for dead, geologically speaking, the moon is showing signs of more recent life.

Left for dead, geologically speaking, the moon is showing signs of more recent life.

True-color and false-color images show one of the lunar valleys in sharp detail.

Explore what the discovery of these lunar valleys tells us about the moon's evolution.

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.

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.

Lunar valleys form when the moon's crust stretches, breaks and drops down along two bounding faults.

Lunar valleys form when the moon's crust stretches, breaks and drops down along two bounding faults.

Since its launch in 2009, LRO has provided unprecedented data and views of the moon's surface.

Since its launch in 2009, LRO has provided unprecedented data and views of the moon's surface.

For More Information

See NASA.gov

Credits

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

This page was originally published on Thursday, April 5, 2012.
This page was last updated on Wednesday, May 3, 2023 at 1:53 PM EDT.