Mars' missing atmosphere may be hiding in plain sight in its crust
Mars' crust might conceal its atmosphere, according to MIT scientists. This is linked to the extensive water reservoirs that once existed on the planet.
9:37 AM EDT, September 27, 2024
Geologists from the Massachusetts Institute of Technology (MIT) argue that a significant portion of Mars' atmosphere may be hidden in its crust. They suggest that carbon dioxide has been transformed into methane and trapped in clay layers.
Mars was not always the desert planet we know today. Billions of years ago, extensive water reservoirs existed on the Red Planet. However, the water disappeared about 3.5 billion years ago, and the thick atmosphere rich in carbon dioxide thinned significantly. Planetologists have long pondered what exactly happened to the Martian atmosphere.
According to MIT experts, most of Mars' atmosphere is hidden in rocks, specifically in the clay present in the planet's crust.
"Based on our findings on Earth, we show that similar processes likely operated on Mars and that copious amounts of atmospheric CO2 could have transformed to methane and been sequestered in clays," says Prof. Oliver Jagoutz, author of the publication in the journal "Science Advances."
There was a lot of water on Mars
Scientists explain that when water was present on Mars, chemical reactions could have occurred due to its interaction with iron. These reactions transformed carbon dioxide into methane, which was then absorbed by the clay. According to Jagoutz, methane could still be there and potentially be used as an energy source in the future.
Experts estimate that up to 80 percent of Mars' former atmosphere could be hidden in the clay. The researchers based their findings on similar chemical reactions observed on Earth.
Last year, additional research was conducted on the mineral smectite, which strongly absorbs carbon. On Earth, smectite was likely the product of tectonic activity and stored significant amounts of carbon dioxide, possibly contributing to the planet's cooling over millions of years.
After examining maps of Mars, scientists noticed that a large part of the planet's surface is covered with clay containing smectite. This layer reaches a depth of more than 0.6 miles. However, Mars lacks the tectonic activity that would create this mineral. Therefore, scientists developed a model to explain how smectite could have been produced in the Martian crust.
"We find that estimates of global clay volumes on Mars are consistent with a significant fraction of Mars’ initial CO2 being sequestered as organic compounds within the clay-rich crust," says Prof. Murray.
"In some ways, Mars’ missing atmosphere could be hiding in plain sight," he adds.
