Did Mars once have a large moon?

[Brian G Turner]

Someone has suggested that Mars used to have a moon about a third of the size of our Moon, to explain a range of odd features about the surface of Mars. I have to admit I'm intrigued:

New hypothesis suggests Mars's unique shape may be due to long lost moon

An astronomer at the U.S. Naval Observatory has developed a hypothesis to explain the unique shape and terrain of Mars. He suggests both are due to a long-lost moon. Michael Efroimsky has published a paper outlining the hypothesis on the arXiv preprint server.

phys.org

 

[Lady of Winterfell]

Interesting theory. And even more interesting to me is what might have happened to said moon Nerio? I find it more likely it was hit and destroyed than simply wandering away. But with Jupiter hanging around who knows.