Where Did Mars’s Water and Atmosphere Go?
New geophysical data suggests that the missing water and carbon atmosphere of Mars are not lost to space, but are instead sequestered deep beneath the planet’s crust. Recent studies from the University of California, Berkeley and MIT indicate that vast reservoirs of liquid water and carbon-trapping clays exist within the Martian subsurface, potentially reshaping our understanding of the planet’s history and future habitability.
How Much Water Is Hidden Under Mars?
According to researchers using data from NASA’s InSight lander, Mars contains enough liquid water to cover the entire planet to a depth of 1 to 2 kilometers (about 0.6 to 1.2 miles). The lander, which monitored seismic “marsquakes” between 2018 and 2022, provided the data necessary to map the planet’s subsurface structure.
Geophysicist Michael Manga of UC Berkeley reports that this water is trapped within the cracks and pores of igneous rocks located 11.5 to 20 kilometers (7 to 13 miles) beneath the surface. While this depth makes current extraction impossible, Manga notes that the existence of this reservoir provides a critical environment that could, in principle, sustain life as we know it.
The InSight lander detected seismic waves that changed speed as they passed through different densities, allowing scientists to “see” the water trapped deep in the Martian crust.
Where Did the Martian Atmosphere Vanish?
Planetary scientists at MIT suggest that approximately 80 percent of Mars’s missing carbon dioxide is trapped in clay minerals known as smectites. While earlier theories posited that solar winds stripped the atmosphere away, MIT researcher Oliver Jagoutz argues that the planet’s crust acted as a chemical sponge.
The process, documented by the MIT team, involves water reacting with iron-rich olivine in the Martian crust. This chemical reaction creates iron oxide—the rust responsible for the planet’s color—and releases hydrogen, which then binds with carbon dioxide to form methane trapped within the accordion-like folds of smectite clays. If the planet’s crust contains a layer of these clays roughly 1,100 meters (0.7 miles) deep, it accounts for nearly 1.7 bar of the planet’s lost carbon dioxide, according to lead researcher Joshua Murray.
How Do Mars’s Resources Compare to Earth?
While Earth and Mars are both rocky planets that likely started with similar primordial atmospheres, their evolutionary paths diverged sharply around 3.6 billion years ago.
| Feature | Earth | Mars |
| :— | :— | :— |
| Magnetic Field | Strong (Protects atmosphere) | Weak (Allows solar stripping) |
| Tectonic Activity | Active (Recycles carbon/water) | None (Stagnant crust) |
| Carbon Content | High | Low (10% of Earth/Venus) |
Earth utilizes plate tectonics and volcanic activity to cycle gases and water between the surface and the mantle. In contrast, the lack of these processes on Mars forced its water and carbon into the crust, effectively locking the planet’s past climate into its geology.
Can Future Explorers Access These Resources?
Extracting water from 20 kilometers underground remains beyond current engineering capabilities, according to NASA mission projections. However, the methane-rich smectite clays identified by the MIT team sit much closer to the surface.
Future missions to Mars, such as those proposed by NASA and the Chinese space agency, may prioritize these clay deposits as a source for fuel production. By mining these minerals, explorers could potentially reclaim a portion of the atmosphere and water that vanished billions of years ago.
When evaluating mission viability, look for landing sites with high concentrations of smectite clays, as these areas represent the most accessible reservoirs of the planet’s historical carbon.
Frequently Asked Questions
Is there liquid water on Mars today?
Yes, according to seismic data from the InSight lander, large volumes of liquid water exist deep beneath the Martian surface.
Why is Mars red?
The red color is caused by iron oxide (rust) on the surface, which formed when oxygen from water reacted with the iron-rich olivine in the planet’s crust.
Could life exist in the underground water reservoirs?
Michael Manga of UC Berkeley states that while no evidence of life has been found, these reservoirs provide a habitable environment similar to deep-sea or subterranean environments on Earth.
Will we ever mine Mars for water?
Current technology is limited to surface exploration; however, future missions may target shallow clay deposits to extract trapped methane for rocket fuel.
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