NASA orbiter detects small troughs growing on Mars which may become 'spiders'

Washington: Researchers have detected cumulative growth of erosion-carved troughs that may be infant versions of larger features known as Martian "spiders".

These are said to be radially patterned channels found only in the south polar region of Mars.

The researchers reported 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 using NASA's Mars Reconnaissance Orbiter (MRO).

"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," Ganna Portyankina of the University of Colorado, Boulder was quoted as saying by NASA.

"These are in sand-dune areas, so we don't know whether they will keep getting bigger or will disappear under moving sand," he added.

"Much of Mars looks like Utah if you stripped away all vegetation, but 'spiders' are a uniquely Martian landform," Candice Hansen of the Planetary Science Institute, Tucson, Arizona, a co-author of the report, was quoted as saying by NASA.

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. 

The scientists found the results exciting as for the past decade, they checked in vain with MRO's High Resolution Imaging Science Experiment (HiRISE) camera to see year-to-year changes in them.

Dunes appear to be a factor in how the baby spiders form, but they may also keep many from persisting through the centuries needed to become full-scale spiders, as per IANS. 

The amount of erosion needed to sculpt a typical spider, at the rate determined from observing active growth of these smaller troughs, would require more than a thousand Martian years. 

One Martian year lasts about 1.9 Earth years.

(With Agency inputs)