The Perseverance rover found dozens of irregularly shaped, millimeter-size off-white splotches, each ringed with black material, akin to leopard spots. (Credit: NASA/JPL-Caltech/MSSS)
PASADENA, Calif. — If there really was life on Mars at some point in the distant past, scientists believe they may have just found a pivotal clue. In a thrilling development on the Red Planet, NASA’s Perseverance rover has stumbled upon a rock that shows signs that it once hosted microbial life.
Nicknamed “Cheyava Falls,” this arrowhead-shaped stone might just hold the key to answering one of humanity’s biggest questions: Was there ever life on Mars?
The six-wheeled Mars rover, known as “Percy” by its fans, has been combing the Martian landscape since 2021. Its mission is to search for signs of ancient microbial life and collect rock samples that can be returned to Earth in the not-too-distant future. Now, it seems Percy may have hit the jackpot.
“Cheyava Falls is the most puzzling, complex, and potentially important rock yet investigated by Perseverance,” says Ken Farley, the mission’s project scientist from Caltech, in a media release.
What makes this particular rock so special?
For starters, Cheyava Falls contains organic compounds — the basic building blocks of life as we know it. While this doesn’t necessarily mean life existed on Mars, it’s certainly a tantalizing clue that it could have at one point. The rock also shows evidence of past water activity, another crucial ingredient for life.
“These spots are a big surprise,” says David Flannery, an astrobiologist and member of the Perseverance science team from the Queensland University of Technology in Australia. “On Earth, these types of features in rocks are often associated with the fossilized record of microbes living in the subsurface.”
Imagine a leopard’s spots, but on a rock. NASA researchers say these millimeter-sized, off-white splotches surrounded by black halos could be signs of ancient microbial activity. On Earth, similar features form when chemical reactions involving a red mineral called hematite turn rocks white. These reactions can provide energy for microbes, which is why scientists are so excited about this discovery.
However, the team is cautious about jumping to conclusions. Other explanations for these features are still on the table. For instance, the rock contains olivine crystals, which typically form from hot magma. This raises the possibility that high temperatures, too hot for life, might have played a role in creating these spots.
“We have zapped that rock with lasers and X-rays and imaged it literally day and night from just about every angle imaginable,” Farley says.
Despite this thorough examination, questions remain. To get definitive answers, scientists would need to study Cheyava Falls in Earth-based laboratories.
This discovery highlights the importance of NASA’s Mars Sample Return mission, which aims to bring Martian rocks back to Earth for detailed analysis. While Percy’s onboard instruments are impressive, they can’t match the power and precision of Earth-based labs.
“We have designed the route for Perseverance to ensure that it goes to areas with the potential for interesting scientific samples. This trip through the Neretva Vallis riverbed paid off as we found something we’ve never seen before, which will give our scientists so much to study,” explains Nicola Fox, associate administrator of NASA’s Science Mission Directorate.
Neretva Vallis, where Cheyava Falls was found, is an ancient river valley about a quarter-mile wide. Long ago, water rushed through this channel into Jezero Crater, the area Percy has been exploring. This watery past makes it a prime spot to look for signs of ancient life.
While the jury is still out on whether Cheyava Falls truly harbors evidence of past Martian life, one thing is certain: this discovery has injected fresh excitement into the search for extraterrestrial life. As scientists continue to explore one of our nearest celestial neighbors, each new finding brings us closer to answering that age-old question: Are we alone in the universe?
