Oceans’ water can remain buried in the earth’s crust and not be lost as previously thought, a new study shows.
Previously it was found that Mars was once wet enough to cover its entire surface with an ocean about 100 to 1500 meters deep water, which contains about half as much water as the Atlantic Ocean of the Earth, NASA in said a statement. Since there is life almost everywhere on earth where there is water, this history of water on Mars raises the possibility that Mars was once the home of life – and possibly still would be.
However, Mars is now cold and dry. Previously, scientists thought that solar radiation and the solar wind removed it from much of its air and water after the Red Planet lost its protective magnetic field. The amount of water that Mars still possesses in its atmosphere, and ice will only cover it with a global layer of water about 20 to 40 meters thick.
Related: Mars may be wetter than we thought (but still not as habitable)
But recent findings suggest that Mars could not have lost all of its water in space. Data from NASA’s MAVEN (Mars Atmosphere and Volatile EvolutioN) mission and the European Space Agency’s Mars Express orbit revealed that at the rate at which water is disappearing from the atmosphere of the Red Planet, Mars would have a global ocean of water lost only about 10 to 82 feet (3) to 25 m deep over the course of 4.5 billion years.
Now scientists find that much of the water that Mars once had may remain hidden in the crust of the Red Planet, locked away in the crystal structures of rocks below the surface of Mars. They presented their findings online on March 16 in the journal Science and at the Lunar Planetary Science Conference.
Using data from rovers on and spacecraft orbiting Mars, as well as meteorites from Mars, the researchers developed a model of the Red Planet to estimate how much water it started with and how much it would have lost over time. Potential mechanisms behind this loss include water escaping into space, as well as being chemically absorbed into minerals.
One way scientists estimate how much water Mars has lost in space involves analyzing hydrogen levels within its atmosphere and rocks. Each hydrogen atom contains one proton in its nucleus, but some possess an extra neutron that forms an isotope called deuterium. Regular hydrogen escapes more easily from the gravity of a planet than heavier deuterium.
By comparing levels of lighter hydrogen and heavier deuterium atoms in Mars samples, researchers can estimate how much regular hydrogen the Red Planet has lost over time. Since each water molecule consists of two hydrogen atoms and one oxygen atom, these estimates of Mars’ hydrogen loss therefore reflect how much Mars water has disappeared, as solar radiation water on Mars has broken down into hydrogen and oxygen molecules.
In the new study, the scientists found that chemical reactions resulted in between 30% and 99% of the water that Mars was initially trapped in minerals and buried in the earth’s crust. Any remaining water was then lost in space, which explains the hydrogen-to-deuterium ratio seen on Mars.
All in all, the researchers suggested that Mars lost 40% to 95% of its water during its Noah period about 4.1 billion to 3.7 billion years ago. According to their model, the amount of water on the Red Planet reached its current levels about 3 billion years ago.
“Mars has basically become the dry, dry planet we know today 3 billion years ago,” lead author Eva Scheller, a planetary scientist at the California Institute of Technology in Pasadena, told Space.com.
The new estimates of the amount of water buried in the Mars crust vary widely due to the uncertainty about the rate at which Mars has lost water in space in the distant past, Scheller noted. She explained that NASA’s Perseverance Rover, which landed on Mars in February, could help refine these estimates, ‘because it goes to one of the oldest parts of the Mars crust, and it could help us reverse the previous process. of water loss. much better to the crust. ‘
Although much of the water Mars had may still be trapped inside its crust, that does not mean that future astronauts to the Red Planet will find it easy to extract the water to help them live there, warns Scheller .
“All in all, there is not much water in the Mars crust yet, so you will have to heat a lot of rocks to get a significant amount of water,” Scheller said.
Originally published on Space.com.