Astronomers Make Massive Discovery on the Far Side of the Moon
by Jason Daley Smithsonian.com
Planetary scientists have identified an abnormally massive area located deep below a crater on the moon’s far side. The lunar feature has a mass five times the size of Hawaii’s Big Island, but the exact reason why this anomaly exists in unclear, according to a new study in the journal Geophysical Research Letters.
The massive blob was discovered by researchers using data from NASA’s 2011 Gravity Recovery and Interior Laboratory, or GRAIL, mission and mapping information from the Lunar Reconnaissance Orbiter. By combining both datasets, researchers found that the abnormal mass is located 180 miles underneath the South Pole-Aitken basin, a huge four billion-year-old crater.
“[The South Pole-Aitken basin] one of the best natural laboratories for studying catastrophic impact events, an ancient process that shaped all of the rocky planets and moons we see today,” says study co-author Peter James, a planetary scientist at Baylor University, in a statement.
The 1,200-mile-wide crater was formed when some large space rock with a heavy metal core smashed into the lunar surface billions of years ago, as Maya Wei-Haas at National Geographic describes. When that happened, the asteroid drilled through layers of the moon’s crust while losing mass of its own.