Study Reveals Mars was Habitable for Longer Than Expected

A recent scientific study revealed that the planet Mars may have remained habitable for much longer than previous estimates suggested. The reason lies in "late" water activity that persisted beneath its surface, even billions of years after its surface lakes and rivers disappeared.

1. New Evidence: Groundwater in Gale Crater

The study was based on data collected by the Curiosity rover inside the Gale Crater and was led by a team from New York University Abu Dhabi (NYUAD).

• The Subject: Examination of the Stimson formation within the crater, an accumulation of ancient sand dunes that have hardened over time (lithified).

• The Conclusion: The transformation of these dunes into rock can only be explained by exposure to water.

• Chemical Compounds: Curiosity's data showed the presence of compounds like Gypsum, which typically only forms in the presence of water.

• Supported Hypothesis: Groundwater flowing from the surrounding mountains seeped through the ancient sand, causing it to harden. The team reinforced this hypothesis by comparing it to similar geological formations in the UAE desert.

2. Implications of "Late" Interactions

The study indicates that these interactions between sand and groundwater occurred after the period when Mars was believed to have lost its atmosphere and surface water completely.

• Transitional Phase: This suggests that the Martian environment did not immediately become an arid desert but went through a transitional phase where water remained active beneath the surface for potentially millions of years.

• Result Consistency: These findings align with a previous study by the same team on the adjacent Greenheugh Pediments formation, which bore similar evidence of late-stage hydration.

3. Ramifications for the Search for Life

Lithified sandstones are considered ideal targets for searching for evidence of ancient life:

• Microbial Biosignatures: On Earth, sandstone preserves imprints of the oldest forms of microbial life. The researchers suggest that the hardened Martian rocks may conceal similar traces, if microbial life ever existed on the planet.

• Future Mission Targets: These areas are considered an ideal target for any future missions searching for "biosignatures" or rock samples that could be returned to Earth for detailed analysis.

• The Atmosphere Puzzle: These results help solve the puzzle of how Mars lost its atmosphere, confirming that groundwater continued to play a key role in shaping the planet's surface and perhaps preserving habitable "pockets" long after the end of the wet eras.