The best area for life on Mars was miles below the surface

A vertically exaggerated, false-colored view of a large, water-carved channel on Mars, called the Dow Wallis. Credit: ESA / DLR / FU Berlin, CC BY-SA 3.0 IGO. 3D sung and painted by Luzendra Ojha

The new study highlights the subsurface melting of ice billions of years ago.

Most habitable area for life Mars It would have been several miles below the surface, probably due to the subsurface melting of a thick ice sheet thickened by geothermal heat, a Rutgers-led study concludes.

The study, published in the journal Science advance, An important question in the science of Mars – what may be known as the unconscious young sun paradox can help resolve this.

“Even though greenhouse gases such as carbon dioxide and water vapor were pumped into early Martian environments in computer simulations, climate models still struggle to support long-term hot and wet Mars,” lead author Luzendra Ojha, An assistant professor in the department said. Earth and Planetary Sciences at the School of Arts and Sciences at Rutgers University-New Brunswick “I and my co-authors propose that the faint young sun paradox can be assimilated, at least partially, if higher in Mars’ past It was geothermal heat. “

Our sun is a large-scale nuclear fusion reactor that produces energy by fusing hydrogen into helium. Over time, the Sun has gradually brightened and warmed the surface of the planets in our solar system. About 4 billion years ago, the sun was extremely fierce, so the climate of early Mars must have been cold. However, the surface of Mars has many geological indicators, such as ancient riverbeds, and chemical indicators, such as water-related minerals, which suggest that the red planet abounded in about 4.1 billion to 3.7 billion years ago (Noachian age). The amount of liquid was water. This apparent contradiction between the geological record and the climate model is the faint young sun paradox.

On rocky planets like Mars, Earth, Venus And heat-generating elements such as mercury, uranium, thorium, and potassium generate heat through radioactive decay. In such a scenario, liquid water can be generated through melting at the bottom of thick ice sheets, even though the sun was still faint. For example, on Earth, geothermal heat forms the West Antarctic ice sheet, subglacial lakes in areas of Greenland and the Canadian Arctic. There is a possibility that a similar melting may help explain the presence of liquid water on Mars 4 billion years ago.

Scientists investigated various Mars datasets to determine whether heating through geothermal heat would be possible in the Noachian era. He showed that the conditions required to melt the subsurface must have been omnipresent on ancient Mars. Even though Mars had a hot and wet climate 4 billion years ago, liquid water can only freeze at great depths, with magnetic fields, atmospheric thinness and subsequent global temperature declines. Therefore, life, if it ever originated on Mars, can follow progressively more liquid water.

“At such depths, life could be sustained by hydrothermal (heating) activity and rock-water reactions,” said Ojha. “So, the subsurface may represent the longest habitable environment on Mars.”

NASAAccording to Ojha, the Mars Insight spacecraft landed in 2018 and may allow scientists to better assess the role of geothermal heat in the habitat of Mars during the Noachian era.

Reference: “Implications for Groundwater Production and Early Martyr Habitat from Geological Heat on the Early Mars” by Luzendra Ojha, Jacob Buffo, Suniti Karunatilake and Matthew Siegler, 2 December 2020, Science advance.
DOI: 10.1126 / Sciadv.abb1669

Scientists from Dartmouth College, Louisiana State University and the Institute of Planetary Sciences contributed to the study.

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