Mars’s missing water and atmosphere finally tracked down
Mars is not the desolate, empty world once depicted in early space exploration, but rather a planet concealing its history deep beneath its surface. Recent geophysical data suggests that the vast majority of the water and carbon dioxide that once blanketed the planet 3.6 billion years ago did not escape into space, but was instead sequestered within the Martian crust. According to research teams from the University of California, Berkeley and MIT, this subterranean storage offers a new perspective on the planet’s potential habitability and future resource availability.
Mars has lost at least 90 percent of its original carbon, a conclusion reached by comparing the relative abundance of carbon to the unreactive gas krypton, which has remained stable over the planet’s 4.6-billion-year history.
Where did the Martian water go?
Planetary scientists have long debated the fate of the liquid water that once formed rivers, lakes, and oceans on Mars. Data from NASA’s InSight lander, which recorded seismic vibrations or “marsquakes” between 2018 and 2022, provided the breakthrough. By analyzing how seismic waves moved through the planet, researchers identified a massive reservoir of liquid water trapped 11.5 to 20 kilometers (7 to 13 miles) underground. Michael Manga of the University of California, Berkeley, notes that this reservoir contains enough water to cover the planet’s surface to a depth of 1 to 2 kilometers.
Samantha Carter observes that the discovery of deep-crust water fundamentally shifts the search for life on Mars. While the surface remains a harsh, radiation-exposed environment, the existence of a deep, potentially stable reservoir provides a plausible, though currently inaccessible, environment that could, in principle, sustain life as we know it.
How was the missing atmosphere trapped?
The disappearance of Mars’s carbon-rich atmosphere is likely linked to the formation of clay minerals known as smectites. An MIT-led research team discovered that these clays, which possess accordion-like folds, are capable of trapping carbon dioxide and methane for billions of years. As water dripped through the Martian crust, it reacted with iron-rich igneous rocks—specifically the mineral olivine—to create iron oxide and methane. This process, according to lead researcher Joshua Murray, sequestered approximately 80 percent of the planet’s missing carbon dioxide within a layer of clay estimated to be 1,100 meters deep.
Can future missions access these resources?
While both NASA and the Chinese space agency have expressed ambitions for human missions to Mars, the accessibility of these trapped resources remains a significant engineering hurdle. The water reservoir is located up to 20 kilometers beneath the surface, making large-scale extraction unlikely for early explorers. However, the methane trapped in smectite clays is located closer to the surface. Analysts suggest that future missions might prioritize mining these clay deposits to harvest methane for use as rocket fuel.
Frequently Asked Questions
Why is Mars’s atmosphere so thin today?
Unlike Earth, Mars lacks plate tectonics and a strong magnetic field to replenish gases or deflect solar winds, which have stripped away much of the planet’s atmosphere and water vapor over billions of years.
Is there evidence of ancient water on the surface?
Yes. Missions including Pathfinder, Spirit, and Opportunity confirmed the presence of sedimentary rocks, minerals like hematite, and physical features like river deltas and flood-strewn boulder fields that require liquid water to form.
Could the underground water sustain life?
According to Michael Manga, the underground reservoir is a potential habitable environment. While no evidence of life has been found, the conditions resemble deep-earth environments on our own planet that currently host biological organisms.
What impact would the discovery of these deep-crust resources have on the timeline for human exploration of the Red Planet?