NASA Says Mars Rover Discovered Potential Biosignature Last Year - UNIVERSE

 

This animation depicts water disappearing over time in the Martian river valley Neretva Vallis, where NASA’s Perseverance Mars takes the rock sample named “Sapphire Canyon” from a rock called “Cheyava Falls,” which was found in the “Bright Angel” formation. Credit: NASA

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A sample collected by NASA’s Perseverance Mars rover from an ancient dry riverbed in Jezero Crater could preserve evidence of ancient microbial life. Taken from a rock named “Cheyava Falls” last year, the sample, called “Sapphire Canyon,” contains potential biosignatures, according to a paper published Wednesday in the journal Nature.

A potential biosignature is a substance or structure that might have a biological origin but requires more data or further study before a conclusion can be reached about the absence or presence of life.  

“This finding by Perseverance, launched under President Trump in his first term, 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, and one that will advance our understanding of Mars,” said acting NASA Administrator Sean Duffy. “NASA’s commitment to conducting Gold Standard Science will continue as we pursue our goal of putting American boots on Mars’ rocky soil.”

Perseverance came upon Cheyava Falls in July 2024 while exploring the “Bright Angel” formation, a set of rocky outcrops on the northern and southern edges of Neretva Vallis, an ancient river valley measuring a quarter-mile (400 meters) wide that was carved by water rushing into Jezero Crater long ago.

“This finding is the direct result of NASA’s effort to strategically plan, develop, and execute a mission able to deliver exactly this type of science — the identification of a potential biosignature on Mars,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “With the publication of this peer-reviewed result, NASA makes this data available to the wider science community for further study to confirm or refute its biological potential.”

The rover’s science instruments found that the formation’s sedimentary rocks are composed of clay and silt, which, on Earth, are excellent preservers of past microbial life. They also are rich in organic carbon, sulfur, oxidized iron (rust), and phosphorous.

“The combination of chemical compounds we found in the Bright Angel formation could have been a rich source of energy for microbial metabolisms,” said Perseverance scientist Joel Hurowitz of Stony Brook University, New York and lead author of the paper. “But just because we saw all these compelling chemical signatures in the data didn’t mean we had a potential biosignature. We needed to analyze what that data could mean.”

First to collect data on this rock were Perseverance’s PIXL (Planetary Instrument for X-ray Lithochemistry) and SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instruments. While investigating Cheyava Falls, an arrowhead-shaped rock measuring 3.2 feet by 2 feet (1 meter by 0.6 meters), they found what appeared to be colorful spots. The spots on the rock could have been left behind by microbial life if it had used the raw ingredients, the organic carbon, sulfur, and phosphorus, in the rock as an energy source.

In higher-resolution images, the instruments found a distinct pattern of minerals arranged into reaction fronts (points of contact where chemical and physical reactions occur) the team called leopard spots. The spots carried the signature of two iron-rich minerals: vivianite (hydrated iron phosphate) and greigite (iron sulfide). Vivianite is frequently found on Earth in sediments, peat bogs, and around decaying organic matter. Similarly, certain forms of microbial life on Earth can produce greigite.

The combination of these minerals, which appear to have formed by electron-transfer reactions between the sediment and organic matter, is a potential fingerprint for microbial life, which would use these reactions to produce energy for growth. The minerals also can be generated abiotically, or without the presence of life. Hence, there are ways to produce them without biological reactions, including sustained high temperatures, acidic conditions, and binding by organic compounds. However, the rocks at Bright Angel do not show evidence that they experienced high temperatures or acidic conditions, and it is unknown whether the organic compounds present would’ve been capable of catalyzing the reaction at low temperatures.  

The discovery was particularly surprising because it involves some of the youngest sedimentary rocks the mission has investigated. An earlier hypothesis assumed signs of ancient life would be confined to older rock formations. This finding suggests that Mars could have been habitable for a longer period or later in the planet’s history than previously thought, and that older rocks also might hold signs of life that are simply harder to detect.

“Astrobiological claims, particularly those related to the potential discovery of past extraterrestrial life, require extraordinary evidence,” said Katie Stack Morgan, Perseverance’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “Getting such a significant finding as a potential biosignature on Mars into a peer-reviewed publication is a crucial step in the scientific process because it ensures the rigor, validity, and significance of our results. And while abiotic explanations for what we see at Bright Angel are less likely given the paper’s findings, we cannot rule them out.”

The scientific community uses tools and frameworks like the CoLD scale and Standards of Evidence to assess whether data related to the search for life actually answers the question, Are we alone?  Such tools help improve understanding of how much confidence to place in data suggesting a possible signal of life found outside our own planet.

Marked by seven benchmarks, the Confidence of Life Detection, or CoLD, scale outlines a progression in confidence that a set of observations stands as evidence of life. 

Credit: NASA

Sapphire Canyon is one of 27 rock cores the rover has collected since landing at Jezero Crater in February 2021. Among the suite of science instruments is a weather station that provides environmental information for future human missions, as well as swatches of spacesuit material so that NASA can study how it fares on Mars.

Managed for NASA by Caltech, NASA JPL built and manages operations of the Perseverance rover on behalf of the agency’s Science Mission Directorate as part of NASA’s Mars Exploration Program portfolio.

To learn more about Perseverance visit: https://science.nasa.gov/mission/mars-2020-perseverance  

Source: NASA Says Mars Rover Discovered Potential Biosignature Last Year - NASA  

Blocked blood flow makes cancer grow faster

Cutting off blood flow can prematurely age the bone marrow, weakening the immune system’s ability to fight cancer, according to a new study from NYU Langone Health.

Published online August 19 in JACC-CardioOncology, the study showed that peripheral ischemia-restricted blood flow in the arteries in the legs-caused breast tumors in mice to grow at double the rate seen in mice without restricted flow. These findings build on a 2020 study from the same team that found ischemia during a heart attack to have the same effect.

Ischemia occurs when fatty deposits, such as cholesterol, accumulate in artery walls, leading to inflammation and clotting that restrict the flow of oxygen-rich blood. When this happens in the legs, it causes peripheral artery disease, which affects millions of Americans, and can increase the risk of heart attack or stroke.

“Our study shows that impaired blood flow drives cancer growth regardless of where it happens in the body,” says corresponding author Kathryn J. Moore, PhD, the Jean and David Blechman Professor of Cardiology in the Department of Medicine, Leon H. Charney Division of Cardiology, NYU Grossman School of Medicine. “This link between peripheral artery disease and breast cancer growth underscores the critical importance of addressing metabolic and vascular risk factors as part of a comprehensive cancer treatment strategy.”

Importantly, the research team found that restricted blood flow triggers a shift toward immune cell populations that cannot efficiently fight infections and cancer, mirroring changes seen with aging.

Systemic Skewing

To examine the mechanisms behind the link between cardiovascular disease and cancer growth, the study authors developed a mouse model with breast tumors and induced temporary ischemia in one hind limb. The team then compared cancer growth in mice with and without impaired blood flow.

Their findings build on the nature of the immune system, which evolved to attack invading bacteria and viruses, and under normal conditions, to detect and eliminate cancer cells. These protective functions rely on stem cell reserves in the bone marrow, which can be activated as needed to produce key white blood cell populations throughout life.

Normally, the immune system responds to injury or infection by ramping up inflammation to eliminate threats, then scaling back to avoid harm to healthy tissue. This balance is maintained by a mix of immune cells that either activate or suppress inflammation. The researchers found that reduced blood flow disrupts this equilibrium. It reprograms stem cells in the bone marrow to favor the production of “myeloid” immune cells (monocytes, macrophages, neutrophils) that dampen immune responses, while reducing output of lymphocytes like T cells that help to mount strong anti-tumor responses.

The local environment within tumors showed a similar shift, accumulating more immune-suppressive cells- including Ly6Chi monocytes, M2-like F4/80+ MHCIIlo macrophages, and regulatory T cells – that shield cancer from immune attack.

Further experiments showed that these immune changes were long-lasting. Ischemia not only altered the expression of hundreds of genes, shifting immune cells into a more cancer-tolerant state, but also reorganized the structure of chromatin-the protein scaffolding that controls access to DNA-making it harder for immune cells to activate genes involved in fighting cancer.

“Our results reveal a direct mechanism by which ischemia drives cancer growth, reprogramming stem cells in ways that resemble aging and promote immune tolerance,” says first author Alexandra Newman, PhD, a postdoctoral scholar in Dr. Moore’s lab. “These findings open the door to new strategies in cancer prevention and treatment, like earlier cancer screening for patients with peripheral artery disease and using inflammation-modulating therapies to counter these effects.”

Moving forward, the research team hopes to help design clinical studies that evaluate whether existing inflammation-targeted therapies can counter post-ischemic changes driving tumor growth.

Source: https://sciencedaily.com/releases/2025/09/250910000311.htm

Journal article: https://www.jacc.org/doi/10.1016/j.jaccao.2025.05.016 

Source: Blocked blood flow makes cancer grow faster – Scents of Science