Why Scientists Think the Moon Is Shrinking

By Andrew Moseman | August 20, 2010 3:11 pm

scarpIs there less of the moon to love than there used to be?

Yesterday came the news that our natural satellite might have shrunk 100 meters in diameter in relatively recent geologic time. The Lunar Reconnaissance Orbiter found a plethora of scarps across the lunar surface, far more than we knew about before. These cliff-like features can appear on Earth from tectonic shifts, but there’s no continental drift on the moon. Thus, the most likely explanation is: The moon shrunk. If it did, the surface would buckle under the pressure and create these scarps. Astronomers say that the gradual cooling of the moon’s interior probably caused the shrinkage.

Don’t worry about the tides disappearing, though. “Recent” means a different thing to geologists than to everyone else, and in this case it has taken a billion years for the moon to shrink in diameter just 0.003 percent.

For plenty more on the find, check out Phil Plait’s post at Bad Astronomy.

Related content:
Bad Astronomy: The Moon Is Shrinking!
80beats: Study: There’s Water on the Lunar Surface, but Inside It’s Bone Dry
80beats: Found on the Moon: A Soviet Laser Reflector That Was Lost for 40 Years

Image: NASA

MORE ABOUT: LRO, moon, plate tectonics
  • ChH

    Gru !?!

  • Thomas Wilkens

    “Thus, the most likely explanation is: The moon shrunk. ”

    Er…I think you meant, “shrank”….?

  • Luke

    @ Thomas Wilkens. Shrunk is fine, itself and shrank are both past participles of shrink. As for the article, that’s pretty cool!


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles covering the day's most compelling topics.

See More

Collapse bottom bar