Mars once was wet earth, with a lot of water on its surface. But this changed dramatically billions of years ago, leaving behind the desolate wasteland known today. Now, what happened to the water? Scientists have a whole new idea.
Investigators said this week that between 30% and 99% of it could now be trapped within the Martian mineral in its crust, contradicting the long-held view that it simply disappeared into space by escaping into outer space.
“We find a lot of Mars water lost due to its crust. Water was lost three billion years ago, which means that Mars was a dry planet today as it is three billion years ago, ”said California Institute of Technology PhD applicant Eva Scheller, lead author of NASA-sponsored research published Tuesday in the journal Science.
At the beginning of its history, Mars may have had a body of water on its surface that is about half the size of the Atlantic Ocean, enough to cover the entire planet with water perhaps as much as a mile and a half.
Water is made up of one oxygen and two atoms of hydrogen. The amount of hydrogen isotope, or alternatively, the so-called deuterium present on Mars has provided some clues about water loss. Unlike most hydrogen atoms with just one proton within the nucleus of an atom, the deuterium – or “heavy” hydrogen – has a proton and a neutron.
Normal hydrogen can escape into space more easily than deuterium. The loss of water in the atmosphere, according to scientists, could leave a much higher rate of deuterium compared to regular hydrogen. Researchers have used a model to compare the composition of hydrogen isotope with water volume on Mars.
“There are three important processes within this range: the installation of water from volcanoes, the loss of water in space and the loss of water from its crust. By using this model and comparing it to our hydrogen isotope data set, we can calculate how much water is lost in space and ice, ”said Scheller.
Researchers have suggested that much of the water did not leave the planet, but it did end up trapped in various water-containing minerals as part of its mineral structure – mud and sulfates in particular.
This trapped water, while seemingly abundant when taken in total, may not provide an effective source of space for future astronaut missions on Mars.
“The amount of water in a rock or mineral is very small. You will have to burn a lot of rock to get water out of a good amount, ”said Scheller.