NASA’s Curiosity rover has made a ‘mind-blowing’ discovery on Mars that scientists said ‘should not be there.’
The one-ton rover uncovered yellowish-green crystals of pure sulfur during its search for chemical evidence that the Red Planet was once habitable.
While minerals containing sulfur have been observed in the Martian world, elemental sulfur on its own has never been seen before.
Curiosity accidently cracked opening white stones as it traveled through the Gediz Vallis channel, revealing the ‘strange’ structures that add to the growing evidence that Mars was once a habitable world.
The one-ton rover uncovered yellowish-green crystals of pure sulfur during its search for chemical evidence that the Red Planet was once habitable
Sulfur is used to make two essential amino acids that are needed for proteins, deeming it a sign of life on Earth.
But scientists have not said Curiosity’s discovery is an indication of past life on Mars.
The find has added to the growing evidence of other life-sustaining elements identified on Mars including carbon, hydrogen, nitrogen, oxygen and phosphorus.
What the discovery does show is that Mars was flowing with water, which is also a key ingredient for life.
Curiosity’s project scientist, Ashwin Vasavada, said: ‘Finding a field of stones made of pure sulfur is like finding an oasis in the desert.
‘It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.’
The ground-breaking discovery was made on May 30 while Curiosity was off-roading within Gediz Vallis channel, a groove that winds down part of the three-mile-tall Mount Sharp – the base of which the rover has been ascending since 2014.
The six-wheeled rover has previously detected sulfur on Mars but only mixed in with other minerals like magnesium and calcium.
When combined with other elements, sulfur gives off a pungent smell, but the pure sulfur found on Mars is odorless.
NASA scientists at the Jet Propulsion Laboratory (JPL) in California first identified a collection of white rocks and issued Curiosity instructions to explore.
The rover sent a close-up image of the white stones back to Earth, which included an ear of crushed rocks near Curiosity’s wheels.
And that is when the team spotted the yellow crystals.
‘I think it’s the strangest find of the whole mission and the most unexpected,’ Vasavada told CNN.
Curiosity made the strange find by accidently cracking opening white stones as it traveled through the Gediz Vallis channel
‘I have to say, there’s a lot of luck involved here. Not every rock has something interesting inside.’
While the sulfur rocks were too small and brittle to be sampled with the drill, a large rock nicknamed ‘Mammoth Lakes’ was spotted nearby.
Rover engineers had to search for a part of the rock that would allow safe drilling and find a parking spot on the loose, sloping surface.
After Curiosity bored its 41st hole using the powerful drill at the end of the rover’s seven-foot robotic arm, the six-wheeled scientist trickled the powdered rock into instruments inside its belly for further analysis so that scientists could determine what materials the rock is made of.
‘No one had pure sulfur on their bingo card,’ said Vasavada.
Sulfur rocks typically feature a ‘beautiful, translucent and crystalline texture,’ the scientists explained.
But the group seen on Mars had been sandblasted for millions of years, which dulled the bright yellow and made them appear reddish like the surrounding landscape.
However, the find has added to the growing evidence of other life-sustaining elements identified on Mars including carbon, hydrogen, nitrogen, oxygen and phosphorus.
Gediz Vallis channel is one of the primary reasons the science team wanted to visit this part of Mars. The region is located just south of the Martian equator.
Scientists think the channel was carved by flows of liquid water and debris, which left an extending two miles down the mountainside below the channel.
The goal has been to develop a better understanding of how this landscape changed billions of years ago, and recent clues have provided insights.
Since Curiosity arrived at the channel earlier this year, scientists have studied whether ancient floodwaters or landslides built up the large mounds of debris that rise from the channel’s floor.
The rover sent a close-up image of the white stones back to Earth, which included an ear of crushed rocks near Curiosity’s wheels. And that is when the team spotted the yellow crystals
The latest clues from Curiosity suggest that both played a role: some piles were likely left by violent flows of water and debris, while others appear to be the result of more local landslides.
These conclusions are based on rocks found in the debris mounds. While stones carried by water flow become rounded like river rocks, some of the debris mounds are riddled with more angular rocks that dry avalanches may have deposited.
Finally, water soaked into all the material that settled here. Chemical reactions caused by the water bleached white ‘halo’ shapes into some of the rocks. Erosion from wind and sand has revealed these halo shapes over time.
‘This was not a quiet period on Mars,’ said Becky Williams, a scientist with the Planetary Science Institute in Tucson, Arizona, and the deputy principal investigator of Curiosity’s Mast Camera.
‘There was an exciting amount of activity here. We’re looking at multiple flows down the channel, including energetic floods and boulder-rich flows.’
