These Spidery 'Veins' On Mars Are Just Plain Weird (Photo)

Spidery 'Veins' on Mars
This photo, captured by NASA's Mars Reconnaissance Orbiter in February 2009, shows spidery troughs on the Red Planet likely formed by the sublimation of carbon dioxide. (Image credit: NASA/JPL-Caltech/University of Arizona)

Nobody knows yet whether or not Mars has ever hosted life, but the Red Planet itself looks strangely alive in a newly released NASA photo.

Slender, branching troughs snake across a pinkish, pitted swathe of the southern hemisphere of Mars in the image, creating an impression (at least to this observer) of blood vessels forking through flesh.

The photo was taken by the High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA's Mars Reconnaissance Orbiter (MRO) on Feb. 4 2009, but the agency featured it online on Monday (Jan. 11). You can see more awesome Mars photos by MRO here.

The complex terrain shown in the image was likely shaped by the sublimation (transition from solid phase to gas) of the seasonal carbon-dioxide ice cap near Mars' south pole, NASA officials said.

"The troughs are believed to be formed by gas flowing beneath the seasonal ice to openings where the gas escapes, carrying along dust from the surface below," NASA officials wrote in a description of the photo Monday. "The dust falls to the surface of the ice in fan-shaped deposits."

The HiRISE image depicts an area 0.6 miles (1 kilometer) wide that lies nearly 82 degrees south of the Martian equator. The photo was captured during springtime in the Red Planet's southern reaches. 

"The image was taken at a local Mars time of 4:56 p.m., and the scene is illuminated from the west with a solar incidence angle of 78 degrees; thus the sun was about 12 degrees above the horizon," NASA officials added in the description.

MRO launched in August 2005 and reached Mars the following March. For the past nine-plus years, the spacecraft has searched for signs of past and present water activity on the Red Planet, scouted out possible landing sites for future crewed and robotic missions and relayed communications from surface craft such as NASA's Curiosity and Opportunity rovers, among other work.

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Mike Wall
Senior Space Writer

Michael Wall is a Senior Space Writer with and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.