The NASA Curiosity rover has sent back new data that supports the theory of potential life on Mars. A recent chemical analysis of Martian soil suggests that conditions suitable for life may have existed on the planet in the distant past, albeit during brief periods. The processes that created life-essential elements may have also contributed to the current dry surface of Mars.
Curiosity, which has been exploring Gale Crater since 2012, focused on finding carbonates—minerals rich in carbon. Carbon is fundamental for life due to its ability to form molecules like DNA and RNA. The research results indicate that while periods of habitability on Mars may have been short, it is possible that living organisms existed beneath the surface.
Using the Sample Analysis at Mars (SAM) instruments, the Curiosity team analyzed carbon and oxygen isotopes in the samples. When heated to 899°C, the samples released gases that were subsequently analyzed with a laser spectrometer. The data revealed higher levels of heavy carbon and oxygen isotopes, suggesting unique conditions on Mars that differ from Earth.
There are two possible explanations for the presence of these isotopes. The first is a cycle of wet and dry periods, during which water evaporated, leaving behind heavier isotopes. The second involves the formation of carbonates in highly saline water at low temperatures, which are generally not conducive to life.
According to Jennifer Stern from NASA, these mechanisms indicate varying climatic regimes on Mars. Some periods may have been relatively suitable for life, while others were not. Although the results may seem discouraging, researchers suggest that life could have existed underground, where conditions might have been more stable and comfortable, at least for microorganisms.
Despite mixed results, the search for life continues. The Curiosity and Perseverance rovers are still exploring Mars, and NASA plans to send humans to the planet in the 2030s or 2040s. If this occurs, it will mark the first time colonists will likely see Mars with their own eyes.
Previously, we reported on how the Curiosity rover discovered pure sulfur on Mars.