A rock on Mars spilled a surprising yellow treasure after Curiosity accidentally crashed through its unassuming surface.
Last May, as the rover rolled its 899-kilogram (1,982-pound) body over the fragile mineral, the deposit cracked, revealing yellow crystals of elemental sulfur, known as sulfur.
Although sulfates are fairly common on Mars, this represents the first pure elemental form of sulfur found on the Red Planet.
RELATED: Curiosity finds first evidence of carbon cycle at ancient Mars site
Even more exciting is that the Gediz Vallis Channel, where Curiosity found the rocks, is littered with objects that look suspiciously similar to the sulfur rocks before they were accidentally crushed—suggesting that, somehow, elemental sulfur may be abundant in some places.
Watch the video below for a summary:
YouTube thumbnail
“Finding a stone made of pure sulfur is like finding an oasis in the desert,” Ashwin Vasavada, Curiosity project scientist at NASA’s Jet Propulsion Laboratory, said in July 2024.
“It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.”
Sulfates are salts formed when sulfur (usually in compound form) mixes with other minerals in water.
When the water evaporates, the minerals mix and dry, leaving behind the sulfates.
These sulfate minerals can tell us a lot about Mars, such as its water history and how it weathered over time.
Pure sulfur, on the other hand, can only form under very limited conditions, which was not the case in the area of Mars discovered by Curiosity.
There’s still a lot we don’t know about Mars’ geological history, but the discovery of large amounts of pure sulfur on the planet’s surface suggests there’s something huge out there that we don’t know about.
Win a Space Coast adventure vacation worth $10,000
It is important to understand that sulfur is an essential element for all life. It is usually absorbed in the form of sulfate and is used to make two essential amino acids that organisms need to make proteins.
Since we’ve known about sulfates on Mars for some time, this discovery doesn’t tell us anything new in the field. Regardless, we have yet to find clear signs of life on Mars.
But we do continue to find remnants of things useful to living organisms, including chemistry, water, and habitable conditions from the past.
Trapped on Earth, our means of getting to Mars are fairly limited.
Curiosity’s instruments are able to analyze and identify sulfur rocks in the Gediz Valley Channel, but if it hadn’t taken a path that tumbled and cracked one of the rocks, it might have been a while before we found the sulfur.
The next step will be to figure out how exactly the sulfur got there based on what we know about Mars.
This will require more work, possibly involving some detailed modeling of Mars’ geological evolution.
In the meantime, Curiosity will continue to collect relevant data.
RELATED: Mysterious streaks on Mars’ slopes may finally be solved
An area rich in Martian history is the Gediz Valley Passage, an ancient waterway whose rocks now bear the imprint of ancient rivers that once flowed billions of years ago.
Curiosity is still moving along the channel to see what other surprises there might be around the next rock.
You can follow Curiosity’s adventures in the Curiosity Science Updates blog .
More than five years into its mission, NASA’s Perseverance rover is still roaming the surface of the Red Planet, doing what any five-year-old loves to do – stopping to look at every rock in its path.
One of its latest discoveries happens to look surprisingly out of place, prompting scientists to wonder if it might not be from Mars after all.
Related: Is there life on Mars? NASA’s surprising discovery is the best evidence yet
On June 19 this year, the six-wheeled explorer set a new record, officially completing the longest road trip of any robotic vehicle on another planet.
The rover rolled 411 meters on the rocky surface of Mars in a single drive. That might not sound like much, but compared to the relatively snail-like pace of Curiosity and Opportunity, Percy is a speed demon.
The Mars robot is truly a miracle. They represent the bravery, resilience and determination of the human spirit. And, of course, our boundless curiosity about the universe in which we live.
An earlier version of this article was published in July 2024.
