The Curiosity rover has discovered something surprising: a rock made of pure sulfur.
National Aeronautics and Space Administration (NASA) Revealed We detailed this discovery in a post last week, detailing the rover’s journey through the Gediz Canyon, a strait thought to have been carved out by a river about 3 billion years ago. The strait is intriguing because the ridges reveal many layers of Martian rock.
This waterway is known as a source of sulfates, salty substances that form when water evaporates. The presence of sulfates is another reason why we visit the waterway in the Gediz Canyon.
During Curiosity’s work, the mobile laboratory crushed rocks, but upon further examination, it was determined that the rocks were composed of pure sulfur.
The yellow sulfur crystals were revealed after NASA’s Curiosity rover drove over and cracked the rock on May 30. Credit: NASA/JPL-Caltech/MSSS – Click to enlarge
Curiosity discovered many more rocks that appear to be chunks of pure, crushed sulfur.
Sulfur only forms under certain conditions, so the presence of so much of it in one place is fascinating and unexpected.
“Finding a rock block made of pure sulfur is like finding an oasis in the desert,” enthuses Ashwin Vasavada, Curiosity project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “It can’t be there, so you have to explain it. Finding strange and unexpected things is what makes planetary exploration so exciting.”
The NASA post did not offer any theory as to the presence of sulfur.
But analysis of what Curiosity saw in the Gediz Canyon waterway provides evidence of several different processes occurring in the landscape.
“Since Curiosity arrived in the strait earlier this year, scientists have been investigating whether large piles of debris that rose from the bottom of the strait are the result of ancient floods or landslides,” the post said, adding that analysis suggests both likely played a role. “Some of the piles appear to have been left behind by powerful flows of water and debris, while others appear to be the result of more localized landslides.”
The condition of the debris found by Curiosity supports that hypothesis: Some of the debris, found in mounds near the waterway, is “rounded like river stones,” while other parts are “covered by more angular rocks likely deposited by dry avalanches.”
To address that issue and the sulfur situation, Curiosity has taken out its drill and drilled a new hole in the Red Planet. The target for the rover’s 41st strike on Mars was a rock formation called “Mammoth Lakes,” chosen as it is close to the sulfur rocks but is larger and less brittle. The sample taken by the drill is currently stored aboard Curiosity for study by the rover’s Mars Sample Analysis (SAM) instrument suite.®
