Space & Astronomy

Mysterious lunar swirls finally explained

By T.K. Randall
September 7, 2018

Image: Earthrise - Apollo 8
Credit: (PD) NASA The unusual formations, which appear more prominent at lower altitudes than at higher altitudes, have remained something of a mystery for years.

Previous studies have indicated that the swirls are associated with powerful, localized magnetic fields on the lunar surface and that they are seemingly less weathered than the surrounding terrain.

"The cause of those magnetic fields, and thus of the swirls themselves, had long been a mystery," said planetary scientist Sonia Tikoo of Rutgers University-New Brunswick."To solve it, we had to find out what kind of geological feature could produce these magnetic fields - and why their magnetism is so powerful."

The answer, it turns out, is that the swirls are caused by subterranean lava tubes that were formed when vast quantities of basalt lava flowed on the Moon up to four billion years ago.

The explanation for the magnetism is that when Moon rock is heated to extreme temperatures in the presence of a magnetic field but without the presence of oxygen, it becomes highly magnetized.

"No one had thought about this reaction in terms of explaining these unusually strong magnetic features on the Moon," said Tikoo. "This was the final piece in the puzzle of understanding the magnetism that underlies these lunar swirls."

Source: Science Alert

Tags: Moon, Swirls