Portuguese 
English 
Spanish 
7 min of reading 
0 comments 
Sample collected by the Perseverance rover on Mars may preserve the most compelling evidence yet found of a potential biosignature on the Red Planet, with organic molecules, minerals associated with chemical reactions, and geochemical patterns in a rock formed approximately 3.7 billion years ago in Jezero Crater.
According to NASA’s Jet Propulsion Laboratory, a sample collected by the Perseverance rover in July 2024, from an ancient dry riverbed in Mars’ Jezero Crater, may preserve evidence of ancient microbial life. The sample was taken from a rock named Cheyava Falls and given the name Sapphire Canyon.
The material contains potential biosignatures, according to an article published in Nature magazine on September 10, 2025. The study underwent a full year of analysis and independent peer review, the most rigorous scientific process available before a claim of this weight is accepted by the scientific community.
“This discovery by Perseverance is the closest we have ever come to discovering life on Mars. The identification of a potential biosignature on the Red Planet is a groundbreaking discovery,” said Sean Duffy, NASA’s acting administrator. No scientist has claimed that life has been discovered, but the evidence is the most compelling ever collected in over 50 years of Martian exploration.
-
Eta Aquarids meteor shower will be visible in Brazil in May: find out where to see and what’s the best time
-
Scientists warn that getting pregnant could become more difficult in the future because extreme heat, microplastics, PFAS, and other toxic substances can act together in the body and affect hormones, human reproduction, and fertility.
-
Rains of almost 200 mm devastate Pernambuco and Paraíba in less than 24 hours, leaving six dead, 2,190 displaced, breaking 30-year rainfall records, and causing landslides that buried a mother and a six-month-old baby in Olinda, while almost 500 people needed to be rescued after being stranded by the floods.
-
A cold air mass gains strength, turns into a cold wave, and could drop temperatures in the South and Southeast for several days, with a peak between May 12 and 13, advancing close to the central region of Brazil, and a risk of storms before the weather change.
Cheyava Falls rock on Mars drew attention for leopard spots in Jezero Crater’s ancient river valley
The story of Cheyava Falls began in July 2024, when Perseverance was exploring the Bright Angel formation, a set of rock outcrops on the northern and southern edges of the Neretva Valley. This ancient river valley, almost 400 meters wide, was carved by water flowing into Jezero Crater billions of years ago.
The rock immediately caught attention due to its appearance. It was an argillite, a fine-grained sedimentary rock formed in still water environments like lakes or river deltas, covered with white and red spots distributed in an irregular pattern. Mission scientists quickly nicknamed these marks “leopard spots.”
Each spot has a white core and a reddish edge. The distribution does not appear random, as it shows regular spacing suggesting a specific geochemical pattern. It was this unusual mineral design that transformed Cheyava Falls into the most important Martian rock ever analyzed by Perseverance.
Perseverance instruments identified organic molecules and minerals associated with biological processes on Earth
Perseverance spent weeks analyzing Cheyava Falls with all available instruments before drilling into it and extracting a rock core.
The PIXL instrument, an X-ray fluorescence spectrometer capable of mapping the chemical composition of individual grains with sub-millimeter resolution, identified a highly relevant combination.
Scientists described the finding as a “cocktail of organic molecules and minerals strongly associated with biological processes on Earth.” In the leopard spots, calcium carbonate, olivine, phosphate, oxidized sulfur, and organic matter were identified.
Calcium carbonate indicates historical water presence on Mars. Olivine reacts with water and can produce hydrogen, an energy source used by terrestrial microorganisms. Phosphate is essential for the metabolism of any known life form, while oxidized sulfur appears in oxidation-reduction reactions used by microbes to obtain energy in environments without light.
Why the expression “potential biosignature” is cautious but extremely important for science
The scientific language used in the case of Cheyava Falls is deliberately cautious, and this caution does not weaken the discovery. It increases its precision. A biosignature is any substance, structure, or pattern that may have a biological origin.
When scientists use the expression “potential biosignature,” they are saying that the evidence is consistent with a biological origin, but that other explanations cannot yet be completely ruled out. In the case of Cheyava Falls, there are two possible scenarios: ancient microorganism activity or specific geochemical processes without life.
The geochemical hypothesis involves serpentinization, a process capable of producing oxidation-reduction reactions without living organisms. The historical point is that, for the first time, a Martian sample has reached the level where the biological explanation needs to be seriously considered by the scientific community.
The biological hypothesis has not yet been confirmed because Mars needs to return the sample to Earth
The reason scientists neither confirm nor rule out the biological hypothesis is technical. The two scenarios, ancient microbial life or serpentinization, can produce similar geochemical patterns. To distinguish one from the other, it would be necessary to analyze the sample with instruments much more sophisticated than any space robot can carry.
These instruments exist only in terrestrial laboratories. The analysis capable of determining whether organic structures are truly biogenic requires state-of-the-art mass spectrometers, transmission electron microscopes, and isotopic techniques capable of differentiating molecules produced by life from molecules generated by inorganic chemistry.
Therefore, the next decisive step is to bring the samples from Mars to Earth. As long as Sapphire Canyon remains inside a titanium tube on the Perseverance rover, the discovery will remain in the realm of the strongest evidence ever found, but not yet definitive proof.
Jezero Crater was chosen because it harbored a lake, rivers, and deltas approximately 3.7 billion years ago
To understand why Jezero Crater was chosen as Perseverance’s landing site, one must understand what that region was like 3.7 billion years ago. Jezero is approximately 45 kilometers in diameter and was formed by an asteroid impact.
After the impact, the crater harbored a lake. The evidence is strong: orbital images show river inflow and outflow channels, deltaic deposits formed when water lost speed upon entering the lake, and preserved rock layers along the crater’s edges.
The Neretva Valley was one of these inflow rivers. It transported water, sediments, and dissolved compounds from a plateau to the west into Jezero Lake for hundreds of thousands to millions of years. Cheyava Falls was found precisely in a transition zone between an ancient river channel and a lacustrine environment.
Bright Angel combines ancient water, fine sediments, and chemistry favorable for preserving signs of life
The Bright Angel formation, where Cheyava Falls was found, is at the point where the Neretva Valley met the northern rim of the crater. This type of environment favors the deposition of fine-grained sediments in relatively still water.
For astrobiologists, this scenario is ideal. It combines persistent liquid water, chemical gradients capable of providing energy, minerals that can catalyze biochemical reactions, and fine sediments that preserve organic matter over geological timescales.
On Earth, analogous environments exist in aquifer discharge zones and ultramafic rocks, where serpentinization produces hydrogen and microbial communities live without sunlight. It is precisely this type of environment that makes Jezero Crater one of the most promising regions to search for ancient life on Mars.
Sapphire Canyon sample is 6 centimeters long and was stored in a titanium tube by Perseverance
Perseverance collected a rock cylinder approximately 6 centimeters long and 1.3 centimeters in diameter from Cheyava Falls on July 21, 2024. This was the mission’s 22nd rock sample.
The sample was hermetically sealed in a titanium tube and stored inside the rover. It will remain there until a Mars sample return mission can retrieve it and transport it back to Earth.
Before and during drilling, Perseverance’s instruments analyzed the rock in detail. SHERLOC, a Raman spectrometer aimed at detecting organic molecules, identified organic matter within the white spots. PIXL mapped the distribution of minerals, and the WATSON camera recorded textures in high resolution.
Spatial pattern of spots reinforces the possibility of chemical reactions associated with microbial life
The most suggestive detail of Cheyava Falls is not just the presence of organic molecules, but how these compounds are distributed. PIXL showed that phosphate, oxidized sulfur, and organic matter coexist in the same microscopic zones of the spots.
In terrestrial rocks where microorganisms have produced oxidation-reduction reactions, it is common to find localized zones with oxidized iron minerals at the edge, reduced minerals in the core, and organic matter concentrated at the interfaces between these areas.
In lifeless terrestrial rocks, where serpentinization generated similar reactions, the pattern is usually more diffuse and less localized. Cheyava Falls exhibits a concentrated pattern. It is this spatial organization that makes the sample so intriguing for astrobiology.
Ancient Mars had a denser atmosphere, rivers, lakes, and potentially habitable conditions
Cheyava Falls formed approximately 3.7 billion years ago, at a time when Mars was very different from the dry, cold planet observed today. On Earth, this period coincides with an extremely primitive phase of life, prior to the complex diversification recorded in later fossils.
3.7 billion years ago, Mars had a denser atmosphere, capable of maintaining pressure compatible with liquid water on the surface under certain conditions. The planet also had a magnetic field generated by a still-active core, which protected part of the surface from solar radiation.
Rivers flowed, lakes persisted for long periods, and the environment’s chemistry offered oxidation-reduction gradients that astrobiologists consider suitable for chemolithotrophic microbial life. If life arose on Mars, this period was one of the best possible windows for its existence.
Mars may have had hundreds of millions of years of conditions favorable for microbial life
If life arose on Mars during this interval, it may have had 400 million to 700 million years of habitable conditions before the planet lost its magnetic field, its dense atmosphere, and most of its surface water.
This time is geologically relevant. On Earth, the oldest fossil records indicate that life evolved from prebiotic organic chemistry to cells with sophisticated metabolism in less than 300 million years.
This does not prove that life arose on Mars. But it makes the search for preserved signs in ancient sedimentary rocks plausible, especially in places like Jezero Crater. Cheyava Falls is exactly in the type of environment where Martian life, if it existed, could have left traces.
Be the first to react!