Mysterious Lunar Swirls on the Moon May be Caused by Crashing Comets
Scientists may have found an explanation for the mysterious lunar swirls on our moon's surface. They've found that the wispy bright regions may have been created by several comet collisions over the last 100 million years.
"We think this makes a pretty strong case that the swirls represent remnants of cometary collisions," said Peter Schultz, a planetary geoscientist at Brown University, in a news release.
Lunar swirls have been debated for years. These twisting, swirling streaks of bright soil stretch for thousands of miles across the lunar surface. Most are found on the unseen far side of the moon, though one famous swirl, called Reiner Gamma, can be seen by telescope on the southwestern corner of the moon's near side.
At first glance, the swirls don't appear to be related to the large impact craters or any other topography. In the 1970s, though, researchers found that the swirls were associated with anomalies in the moon's crustal magnetic field. Yet now, researchers may have another theory to explain these swirls, which has its roots in watching the lunar modules land during the Apollo program.
"You could see that the whole area around the lunar modules was smooth and bright because of the gas from the engines scoured the surface," said Schultz. "That was part of what got me started thinking comet impacts could cause the swirls."
Comets carry their own gaseous atmosphere, called a coma. In this case, the researchers theorized that when small comets slam into the moon's surface, the coma may scour away loose soil and may produce the bright swirls.
The researchers actually used computer simulations to see whether comet impacts could produce this kind of scouring. The new simulations revealed that the impact of a comet coma plus its icy core would indeed have created the swirls and that some may stretch thousands of kilometers from the impact point.
"This is the first time anyone has looked at this using modern computational techniques," said Schultz. "everything we see in simulations of comet impacts is consistent with the swirls as we see them on the moon. We think this process provides a consistent explanation, but may need new moon missions to finally resolve the debate."
The findings are published in the journal Icarus.
For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).