Erosion-carved troughs that grow and branch during multiple Martian years may be infant versions of larger features known as Martian “spiders,” which are radially patterned channels found only in the south polar region of Mars.
Researchers using NASA’s Mars Reconnaissance Orbiter (MRO) report the first detection of cumulative growth, from one Martian spring to another, of channels resulting from the same thawing-carbon-dioxide process believed to form the spider-like features. [Their work is published in a recent paper in the journal Icarus.]
The spiders range in size from tens to hundreds of yards (or meters). Multiple channels typically converge at a central pit, resembling the legs and body of a spider. For the past decade, researchers have checked in vain with MRO’s High Resolution Imaging Science Experiment (HiRISE) camera to see year-to-year changes in them.
“We have seen for the first time these smaller features that survive and extend from year to year, and this is how the larger spiders get started,” said Ganna Portyankina of the University of Colorado, Boulder. “These are in sand-dune areas, so we don’t know whether they will keep getting bigger or will disappear under moving sand.” [More at links]