Researchers from the California Institute of Technology (Caltech), University of Colorado and NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, have developed a new model that deals with the connection between Mars' atmosphere and ice deposits, Phys.org reports.
According to the media outlet, the team sought to confirm a theory brought forth in 1966 by two Caltech scientists who postulated that the presence of the thin carbon dioxide atmosphere on Mars, first detected by the Mariner IV spacecraft, could be explained by the existence of "a long-term stable polar deposit of CO2 ice" on the planet that would "control global atmospheric pressure".
The new model explores the existence of a layered deposit of ice water and CO2 ice at the south pole of Mars which apparently contains as much CO2 as the planet's entire atmosphere today.
"Usually, when you run a model, you don't expect the results to match so closely to what you observe. But the thickness of the layers, as determined by the model, matches beautifully with radar measurements from orbiting satellites," said Peter Buhler, Ph.D. of JPL and the model's author.
The researchers suggest that the deposit formed due to Mars' wobbling on its rotational axis over the past 510,000 years, which led to the pole receiving varying amounts of sunlight.
Thus, ice formed when the pole was receiving less sunlight, but sublimed during the sunnier periods of time, with this cycle leading to the creation of alternating layers of water and ice.
"Our determination of the history of Mars's large pressure swings is fundamental to understanding the evolution of Mars's climate, including the history of liquid water stability and habitability near Mars's surface," Buhler remarked.