Mars 'spiders' pop in NASA orbiter image

NASA's MRO highlights some creepy-crawly Martian landscape features.

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.
Amanda Kooser
2 min read

Thousands of spiders are visible in the full NASA MRO image.

NASA/JPL/University of Arizona

Sorry, the "spiders" of Mars don't have anything to do with Ziggy Stardust. They are landscape features that have truly earned their arachnid-related nickname, however. 

An image acquired by NASA's Mars Reconnaissance Orbiter (MRO) shows the dark formations, more technically known as araneiforms, spreading out against a lighter background. NASA says they're "characterized by multiple channels converging at a point, resembling a spider's long legs."

The team for the HiRise camera, run out of the University of Arizona, highlighted the MRO image on Twitter this week along with a shout-out to Planet Four, a citizen science project helping scientists identify features on Mars to study in more detail.

Planet Four volunteers look through images of the southern polar region of Mars, seeking out interesting formations known as fans and blotches. Their efforts help the MRO team plan where to take future images. 

"The human mind is far superior at analyzing images with the complexity of the Martian surface," Planet Four says.   

The HiRise team verified some of Planet Four's findings by spotting these spiders, which it describes as "features with radial troughs from which fans emanate in the springtime."

We've seen spidery imagery from the MRO before, including a dramatic view from earlier this year

The spiders are created by a seasonal process caused by sub-surface carbon dioxide ice warming up and changing from a solid to a gas. The gas eventually breaks through as a jet that can deposit darker dust streaks around it. And that's how we get one of Mars' most intriguing, and potentially creepy, topographic sights.

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