A new study of the terrestrial desert shows that technology can not always detect signs of life even on the surface of our planet, not to mention Mars. The scientific article was published in the journal Nature Communications.
In Chile’s Atacama Desert, there is an ancient delta called the Red Stones, which contains sand and rocks rich in hematite and mudstone. Geologically, this region is very similar to Mars, which is why astrobiologists often use it as a model for the Red Planet.
First, the researchers sequenced DNA found in the local soil. Many genetic sequences have been found, including hitherto unknown species of microorganisms.
Samples from the Red Rocks have also been analyzed using instruments used on or destined for Mars. In most cases, they found nothing or almost nothing.
Last year, the Perseverance rover discovered “clear signs” of organic matter on Mars while driving through an ancient river delta. A few years earlier, the Curiosity rover had found signs of organic molecules in both sand and dried mud.
These are promising discoveries, but organic matter is not a sure sign of life. It is still unclear whether these molecules are actually of biological origin.
“Our analyzes with test instruments that are on Mars or will be sent to Mars indicate that while the mineralogy of the Red Rocks is consistent with that found by ground-based instruments on the Red Planet, the same low levels of organics would be difficult, if not impossible, to detect in Martian rocks, depending on the tool and technique used. Our results highlight the importance of moving samples to Earth to finally resolve the question of whether life ever existed on Mars,” the researchers conclude.
NASA has long been developing a project to transfer Martian soil samples to Earth. The date of this historic moment is currently hidden somewhere in the 2030s.