'Thigh bone' on Mars? NASA explains an unusual find

Space-alien theorists have gotten a thrill from a bone-like object found on Mars, but NASA has a more plausible explanation.

Amanda Kooser
Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.

Bone-shaped rock on Mars
Sorry, folks, no proof of alien life on Mars here. NASA/JPL-Caltech/MSSS

A newly published photo of Mars taken by NASA's Curiosity rover could send you racing to alert the local CSI crew.

An image caught by the rover's MastCam on August 14 shows a collection of rocks, half buried in dust. One in particular stands out. It looks quite a bit like a femur bone from a thigh.

This is all it takes to get alien fanatics excited about the possibility of fossilized alien remains on Mars. However, an alien femur on Mars is no more real than the uneaten jelly doughnut on the Red Planet or the infamous monument to Elvis.

NASA said Thursday its science team members expect that the rock was shaped through erosion caused by wind or water. NASA knows how images of odd objects can stir up the public imagination, so the space agency gives this preemptive statement: "If life ever existed on Mars, scientists expect that it would be small simple life forms called microbes. Mars likely never had enough oxygen in its atmosphere and elsewhere to support more complex organisms. Thus, large fossils are not likely."

The thigh-bone-looking rock actually looks different from a regular human femur. It's crooked, rather than straight, which only feeds the imagination when it comes to alien anatomy. Chalk this up to the human tendency to try to make sense out of random shapes.