A team of scientists in the US have discovered nickel compounds in Martian rocks, in an arrangement similar to organic carbon compounds understood to be formed by living organisms on Earth.
The researchers stress that there may be other explanations for the finding. The group led by Purdue University’s Henry Manelski used data from NASA’s Perseverance rover collected in 2024 when it explored Neretva Vallis, an ancient river channel that once transported water into Jezero crater.
Using the space robot’s infrared and X-ray spectrometers to examine 3-billion-year-old sedimentary rocks and rock surfaces, the researchers found nickel in some samples at concentrations up to 1.1 percent, the highest yet detected in Martian bedrock.
The reason for the interest in this particular metal element is its relationship to the creation of organic compounds on Earth, where research has suggested that iron sulfides in sedimentary rocks could be made by anaerobic respiration in microbes using sulfates in the presence of iron-containing minerals.
Iron sulfides have also been found in Mars’s Neretva Vallis in the presence of organic carbon compounds. Nickel helps form enzymes in some ancient archaea and bacterial species, researchers have noted.
“While the observations presented in this work do not necessarily imply that the distribution of nickel is related to a biological process, the presence of strong enrichments suggests it was bioavailable,” the researchers said in a paper published in Nature Communications today.
“As an element essential to the earliest known forms of life on Earth, and a particularly scarce trace metal, the elevated concentrations of nickel – co-located with organic matter – offers an intriguing hint of past organic-driven… processes on Mars,” the paper said.
Before anyone gets too excited, it’s worth noting that the paper does not provide evidence such organisms existed. It’s also true that nickel compounds could have been formed by other reactions in the absence of living organisms.
Nonetheless, the finding merits further research. And there we come to Mars’s inconvenient remoteness.
“As an essential element for terrestrial microbial life, the proximity of nickel enrichments to reduced sulfur and organic matter adds to the interest in bringing back to Earth the rock sample collected by Perseverance at this location, which could provide key insights into complex… chemistry on early Mars,” the paper said.
Unfortunately, the US Congress approved the Trump administration’s plan to cancel NASA’s Mars Sample Return program in January. ®
