NASA scientists have announced that an unusual rock found by the Perseverance rover on Mars in 2024 may contain the most convincing potential trace of ancient life yet, but they stress that additional research and the return of the sample to Earth are needed before any final statement can be made. The rock is nicknamed Cheyava Falls, after a waterfall in the Grand Canyon, and is located in an ancient river bed in the Bright Angel region within the Lake Crater.
The photos clearly show white “žils” of calcium sulfate and reddish bands rich in hematite, the mineral that gives Mars its characteristic color. The most interesting, however, are the tiny light spots a few millimeters in size, surrounded by a thin dark ring – they look like “leopard spots”. Similar structures on Earth are created when chemical reactions bleach red rock, release iron and phosphate and create dark “halo” zones around bright spots – and such reactions here are often accompanied by microbes that use these compounds as a source of energy.
Instruments on Perseverance showed that the rock contains organic compounds – carbon molecules that are the building blocks of life – and iron phosphate and sulfide minerals (vivianite and greigite) in these spots. Another good news for astrobiologists: everything points to the fact that the rock was formed in a cold, moist environment, without subsequent “baking” at high temperatures, which means that possible traces of microbes were not destroyed later.
That’s why the NASA team labeled this rock as a possible signature of former life – and placed it on the first step, “possible signal”, on the special CoLD life detection scale. Some in the agency go further and say that this “could be the clearest sign of life we’ve ever found on Mars”, but they also add great caution: the same sample could have been created completely without microbes, just by chemistry in mud that is more than 3 billion years old.
Perseverance is from Cheyava Falls andć drilled the core and stored it in a tube as its 22nd sample, to be brought back to Earth one day by a future sample return mission. Only in laboratories on Earth can one look for real micro-fossils or clearer chemical signatures of life under a microscope. Until then, the “leopard rock” remains what NASA officially calls it – the most exciting, but still unproven, clue that Mars may once have been alive.