News from Brock University in St. Catharines, Ontario
Posted September 12th, 2025 on Niagara At Large
Niagara, Ontario – New research supported by Brock University Earth Sciences professors has uncovered findings that could provide the clearest sign of ancient life ever found on Mars.
As members of the Mars 2020 PIXL Instrument Science Team, Mariek Schmidt and Tanya Kizovski were part of an international effort that discovered a potential “biosignature” in a sample collected by NASA’s Perseverance Mars rover.
Biosignatures are a substance, feature or pattern that could suggest the presence of either past or present life.
While further study is required to definitively confirm the findings, scientists have indicated that a biological explanation for features identified within the rocks cannot be dismissed.
“This is the most significant finding to date by the Perseverance rover,” says Schmidt, a Co-Investigator on the Mars 2020 PIXL Instrument Science Team.
Brock researcher Mariek Schmidt
“When we sent Perseverance to Jezero Crater, we were making an educated guess that we’d find evidence of past life. Now we know that the suspicions were possibly confirmed. Once the samples are hopefully brought to Earth, we will be able to definitively confirm it.”
The findings were announced during a media conference hosted by NASA on Wednesday, Sept. 10. The discovery is also the subject of a peer-reviewed paper, co-authored by Schmidt and Kizovski, recently published in Nature<https://www.nature.com/articles/s41586-025-09413-0>.
Called “Sapphire Canyon,” the sample was collected in July 2024 from a set of reddish, clay-rich mudstones found on the edges of Mars’ Neretva Vallis, a river valley created by water that once flowed into the planet’s Jezero Crater more than three billion years ago. The Perseverance Rover has been exploring this area since February 2021.
Through detailed analysis, the research team identified a series of iron-, sulfur- and phosphorus-bearing minerals within a collection of outcrops informally named ‘Bright Angel,’ located in the northern margin of Neretva Vallis.
Two minerals appeared to have formed because of chemical reactions between mud making up the ‘Bright Angel’ outcrops and organic matter: vivianite, an iron phosphate mineral, and greigite, an iron sulfide mineral.
Kizovski says the textural relationships between these minerals and their association with organics provides strong evidence of a potential biosignature.
Using the Planetary Instrument for X-Ray Lithochemistry (PIXL), which rapidly measures elemental chemistry on Mars remotely from Earth, Schmidt and Kizovski contributed to the textural, chemical, spectral and analyses on the sample and related outcrops.
“When we’re trying to figure out if an environment was potentially habitable or if there are biosignatures present, we look at the minerals that formed from that environment, their textural relationships, and then tease back the conditions that would have caused these minerals to form,” Kizovski, a PIXL Science Team Associate Researcher, says. “The data from the PIXL was crucial for this work.”
The team identified fine-grained outcrops in the ‘Bright Angel’ region and upon closer inspection, unusual features were discovered on the surfaces of the mudstones.
“It looked like nothing we had seen previously because there are sub-millimetre spots that are lighter in tone in the centre with a dark ring of reduced, iron-containing phosphates around them. The team called them ‘leopard spots,’” says Schmidt. “Knowing that organics and reduced iron can be associated with one another, and that on Earth, these sorts of textures can be attributed to life, it was a very exciting discovery.”
In prior research conducted within Jezero Crater<https://www.nature.com/articles/s41467-025-60026-7#:~:text=The%20identification%20of%20secondary%20Fe,and%2For%20within%20the%20Jezero>, Kizovski and Schmidt also identified multiple iron phosphates related to the mineral vivianite in a different outcrop called Onahu. This provided evidence that many of the materials and energy sources needed for conditions that may support life could have once existed within Mars’ Jezero Crater.
A representative sample that may contain iron phosphate minerals was collected from an outcrop on Mars, about 30 metres from Onahu on sol 822 of the Perseverance mission.
“The identification of iron phosphates in Onahu is not considered a potential biosignature as these minerals can form without biological inputs, they are not associated with organics, and they do not have the same textural context as the iron phosphates identified within ‘Bright Angel,’” says Kizovski.
“However, finding evidence of vivianite on Mars is really exciting on its own because it could have originally precipitated in conditions favourable to potential ancient life on the planet, which includes the presence of phosphorus, water, low temperature and a neutral pH.”
Kizovski and Schmidt’s contributions to this work were funded through the Canadian Space Agency. Kizovski completed part of this research while she was a postdoctoral fellow at Brock, under the supervision of Schmidt, and working as the former Associate Curator of Mineralogy at the Royal Ontario Museum.
More information on NASA’s Mars 2020 Perseverance rover mission is available on the Mars 2020 website<https://science.nasa.gov/mission/mars-2020-perseverance/>.
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