Scientists have put forward new assumptions about the once dense atmosphere of Mars - perhaps it was not there at all.
From the moment when more and more complex orbital and descent vehicles discovered evidence of former rivers, lakes, and possibly even oceans, once on its surface, scientists were interested in one question - how was this possible? The temperature on the surface of the planet is very low, with carbon dioxide in the atmosphere causing rapid evaporation of water.
The most common explanation for this phenomenon is that 3 billion years ago, the planet's atmosphere was dense enough to hold heat and keep water in a liquid state on the surface of the planet.
The ongoing mission of NASA MAVEN is conducted to test the theory of the “escape of carbon” into space, but the latest computer models of the upper layers of Mars suggest lower numbers, as published in the journal Nature Communications.
In addition, scientists have not found enough carbon elements on the surface of the planet, given the big change in the atmosphere.
"Not a single mechanism, alone or in combination, fully explains the" missing carbon "," writes Reju Hu and his colleagues at the NASA Radiation Facility Laboratory in Pasadena, California, in the journal Nature Communications.
Their research went the other way. The study of atmospheric and mineralogical data collected by NASA's Curiosity rover and other samples prompted scientists to the possibility of other scenarios that do not require a particularly dense atmosphere on Mars in the distant past. Perhaps Mars had a moderately flat atmosphere that resembles or has a slightly lower density than Earth's atmosphere.
"Such an atmosphere can be transformed into the existing one, with the exception of the problem of" missing carbon "," - wrote scientists from NASA in the summary to the study.
“Our work shows that the transition from moderately dense to the existing atmosphere is quite possible,” Dr. Hu said in a NASA statement after defending his doctoral dissertation.
"This exciting information that we know about the atmosphere of Mars can now be transformed into a complete picture of its evolution. And this picture does not require a large amount of unrecorded carbon," he added.
"The moderate atmosphere is a sufficient explanation of the chemical composition of water found in Martian rocks and geological evidence of the existence of lakes," said scientist Bethany Elman from JPR and the California Institute of Technology.
"Many rock formation processes may have occurred under the surface of the planet and for a short time close to the surface," said Elman. "Of course, many lakes on Mars, as well as on our planet, feed on groundwater, in addition to the waters that fill it."
“The big question is whether melting of ice and snow is enough or is it raining to explain some of the questions of morphology?” She added.