NASA’s HiRISE spacecraft, which is currently orbiting Mars, spotted these interesting patterns, which are actually rare lava flows. This is the first time that lava flows have been seen on Mars, and the corkscrew snail shell-like patterns are indicative of previous volcanic activity.
The formations are in an area called Athabasca Valles, which is a tear-shaped landform thought to have been created by catastrophic flooding. These kinds of coils are sometimes seen on Earth, in the ropey pahoehoe lava flows on the Big Island of Hawaii or in the submarine Galapagos Rift at the bottom of the Pacific Ocean.
The Martian lava coils are about 100 feet across, much larger than the ones found on Earth, which are only about a foot in size. These coils are formed when two lava flows move past each other at different speeds. The lava swirls and bunches. When it hardens, it leaves behind these patterns.
The research was published in the journal Science. Lead author Andrew Ryan, from Arizona State University, performed an analysis using more than 100 high-resolution images. The coils couldn’t have been formed by ice or water-related processes.
Ryan has found nearly 200 lava coils in the Cerberus Palus region, and believes that there are more. He expects to find more in Elysium.
Reference: “Coils and Polygonal Crust in the Athabasca Valles Region, Mars, as Evidence for a Volcanic History” by Andrew J. Ryan and Philip R. Christensen, 27 April 2012, Science.