NASA's Perseverance rover has made a fascinating discovery on Mars—a rock named "Cheyava Falls" that may hold clues about the planet's ancient past and the potential for past microbial life. The science team has identified chemical signatures and structures that suggest the rock could have been formed by life billions of years ago when the area was submerged in flowing water.

On July 21, Perseverance collected its 22nd rock core sample from Cheyava Falls, located in the northern edge of Neretva Vallis, an ancient river valley within Jezero Crater. This specific location was carefully chosen by scientists to maximize the chances of finding scientifically interesting samples.

Analysis conducted by instruments aboard the rover, including SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals), revealed the presence of organic compounds within the rock. While organic compounds are considered the building blocks of life, they can also be generated through non-biological processes.

Ken Farley, Perseverance project scientist of Caltech, described Cheyava Falls as the most puzzling and potentially significant rock investigated by the rover. It not only contains organic material but also showcases distinctive colorful spots that could indicate chemical reactions suitable for microbial life. Additionally, evidence of water that flowed through the rock further supports the possibility of ancient life.

Of particular interest to the science team are the irregularly shaped off-white spots on the rock, reminiscent of leopard spots. Perseverance's PIXL (Planetary Instrument for X-ray Lithochemistry) instrument determined that these spots contain iron and phosphate, which are often associated with the fossilized remains of microbes in terrestrial rocks.

One hypothesis suggests that Cheyava Falls was initially composed of mud mixed with organic compounds, which eventually solidified into rock. Subsequently, a second episode of fluid flow introduced mineral deposits, resulting in the formation of the white calcium sulfate veins along with the distinctive spots.

In addition to the organic matter and leopard spots, the presence of olivine crystals within the veins has further perplexed the scientists. Olivine is a mineral typically formed from magma, suggesting a possible link to rocks that formed higher up the river valley's rim and were produced by magma crystallization. This poses the question of whether the olivine and sulfate could have been introduced to the rock through abiotic chemical reactions at high temperatures.

While Perseverance has extensively examined Cheyava Falls using various instruments, the science team acknowledges that further research and analysis are needed to fully understand the rock's origins and potential for ancient life. Bringing back a sample like Cheyava Falls to Earth for comprehensive laboratory study would provide valuable insights that cannot be obtained solely on Mars.

This remarkable discovery showcases the success of Perseverance's mission to explore Mars for signs of past life. The search for evidence of ancient microbial life continues, and the findings from rocks like Cheyava Falls contribute to our understanding of the red planet's history and potential for habitability.