'Underground life': NASA's Curiosity rover uncovers new clues of Mars' shift from habitable to harsh conditions
Produced by: BT Desk
Curiosity Rover's Findings
NASA's Curiosity rover, currently exploring Gale crater on Mars, has uncovered new evidence on how the ancient Martian climate transitioned from potentially habitable to the inhospitable conditions seen today.
Isotopic Analysis of Carbonates
Researchers used Curiosity's onboard instruments to measure the isotopic composition of carbon-rich minerals (carbonates) in Gale crater. The findings reveal significant changes in Mars' ancient climate, characterized by extreme evaporation.
Evaporation Clues
The isotope values in the carbonates suggest that the minerals formed in a climate that only briefly supported liquid water. This supports the theory of transient, rather than stable, liquid water on the surface of Mars in its distant past.
No Evidence of Surface Life
While the samples show no signs of an ancient surface biosphere on Mars, the research does not rule out the possibility of past underground life or life that existed before the formation of these carbonates.
Two Climate Scenarios
The study proposes two mechanisms for the formation of carbonates—one involving wet-dry cycles, indicating alternating habitable and less-habitable periods, and another involving cold, salty conditions under ice, suggesting a much harsher climate.
Unique Isotopic Values
The isotopic values found in Martian carbonates are higher than those recorded for carbonate minerals on Earth, pointing to extreme evaporation processes on Mars that influenced the preservation of these heavy isotopes.
Scientific Significance
Carbonates are important to scientists because they act as climate records, retaining information about the temperature, acidity, and chemical composition of the environment in which they formed.
Instrumental Analysis
The discoveries were made using Curiosity’s Sample Analysis at Mars (SAM) and Tunable Laser Spectrometer (TLS) instruments, which heated the samples and analysed the gases released to provide insights into Mars' ancient climate.