Most of Mars' water could remain in the hard rocks of the planet. This is stated in a study published in the journal Science.
Scientists came to this conclusion, based on data from Mars rovers and spacecraft, a model of the Red Planet. With the help of the model, it was possible to estimate how much liquid was on Mars at the initial stage of its existence and how much was lost over time. One way to estimate the amount of water is to analyze the levels of hydrogen in its atmosphere and rocks.
The study says that each hydrogen atom contains one proton in its nucleus. However, some of the atoms have an extra neutron that forms an isotope known as deuterium. Usually, the lighter hydrogen is volatilized by the planet's low gravity into space, while the heavier deuterium remains. By comparing the content of hydrogen and deuterium, scientists were able to estimate how much ordinary hydrogen Mars could lose over time and explain the mystery of the disappearance of water.
It turned out that in the period from 4.1 to 3.7 billion years ago, the volume of water on the Red Planet decreased by about 40-95 percent. At the same time, a significant or large part of the liquid – from 30 to 90 percent – was absorbed by minerals during the hydration process. “Mars became a dry and arid planet as we know it today about three billion years ago,” said lead author and Caltech researcher Eva Scheller.
At the same time, it cannot be said that the liquid accumulated in the solid rocks of Mars can be easily extracted and used by the first colonizers of the planet for their purposes. “They will have to heat a lot of stones to get the right amount of water,” Scheller said.
According to early research, Mars contained enough liquid to cover the entire surface of the planet with oceans ranging from 100 to 1,500 meters deep. This is approximately half of the water found in the Atlantic Ocean. Scientists are interested in this issue, since usually the presence of water indicates the existence of certain forms of life.
In November 2020, experts from the University of Arizona said that a large amount of Martian water could be in the upper atmosphere. Then the liquid evaporated as a result of photolysis.