Scientists from MIT and elsewhere have reconstructed the extreme collision that created one of the moon’s largest craters, 3.8 billion years ago. The team has retraced the moon’s dramatic response in the first hours following the massive impact, and identified the processes by which large, multi-ring basins can form in the aftermath of such events.
The findings, published today in two papers in the journal Science, may shed light on how giant impacts shaped the evolution of the moon, and even life on Earth, shortly after the planets formed.
The team’s results pertain to the moon’s Orientale basin, an expansive, bull’s eye-shaped depression on the southwestern edge of the moon, just barely visible from Earth. The basin is surrounded by three concentric rings of rock, the largest one stretching 580 miles across — about three times as wide as the state of Massachusetts. Until now, it’s been unclear how such massive, multi-ring basins materialized.
Using data collected by NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, the researchers determined that the 3.8-billion-year-old basin was created by a huge impactor that punched an initial, transient crater into the lunar surface, measuring up to 285 miles in diameter — about as wide as the state of New York. … (MIT)