NASA finds rock on Mars with signs of possible microscopic life billions of years ago

Jul 26. () –

NASA’s Perseverance rover has discovered an “intriguing” rock on Mars nicknamed Cheyava Falls in Jezero Crater, which has some spots that scientists believe may indicate that Billions of years ago, chemical reactions in this rock could have supported microbial life..

The rock, full of veins and shaped like an arrowhead, contains “fascinating” features that may have relation to the question of whether Mars hosted microscopic life in the pastNASA reported.

Analysis by instruments on board the rover indicates the rock has qualities that fit the definition of a possible indicator of ancient life. The rock has chemical characteristics and structures that possibly formed billions of years ago, when the area contained running water.

The science team is considering other explanations for the observed features and future research steps will be required to determine if ancient life is a valid explanation.

The rock — the rover’s 22nd rock sample — was collected July 21 as the rover explored the northern rim of Neretva Vallis, a 1,300-foot (400-meter) wide ancient river valley that was carved by water rushing into Jezero Crater long ago.

“We designed Perseverance’s route to ensure it reaches areas with the potential to obtain interesting scientific samples“says Nicola Fox, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington, noting that this trip along the Neretva Vallis riverbed “was worth it” because they found something they had never seen before, “which will give scientists a lot to study.”

Multiple scans of Cheyava Falls by the rover’s Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument indicate that it contains organic compounds. While these carbon-based molecules are considered the building blocks of life, they can also be formed through nonbiological processes.

“Cheyava Falls is the most puzzling, complex and potentially important rock Perseverance has investigated so far“said Ken Farley, Perseverance project scientist at Caltech in Pasadena.

The rock measures one meter by 0.6 meters and is named after a waterfall in the Grand Canyon. In its search for signs of ancient microbial life, the Perseverance mission has focused on rocks that may have been created or modified long ago by the presence of water. That’s why the team focused on Cheyava Falls.

Large white veins of calcium sulphate run through the rock. Between them are bands of material whose reddish colour suggests the presence of hematite, one of the minerals that gives Mars its characteristic rusty hue.

When Perseverance took a closer look at these red regions, it found dozens of irregularly shaped, millimeter-sized whitish patches, each surrounded by black material, similar to the spots on a leopard. Perseverance’s Planetary Instrument for X-ray Lithochemistry (PIXL) has determined that these black halos contain iron and phosphate.

On Earth, these types of rock features are often associated with the fossilized record of microbes living underground. These types of stains in terrestrial sedimentary rocks can occur when chemical reactions involving hematite cause the rock to turn from red to white.

These reactions can also release iron and phosphate, which may cause the formation of black halos. Reactions of this type can be a source of energy for microbes, which explains the association between such features and microbes in a terrestrial environment.

In a scenario that is being considered by the scientific team of ‘Perseverance‘, Cheyava Falls was initially deposited as mud with mixed organic compounds that eventually cemented into rock.

Later, a second episode of fluid flow penetrated the rock fissures, allowing mineral deposits to form that created the large white veins of calcium sulphate seen today and which gave rise to the stains.