Mars' Missing Atmosphere May Be Trapped in Planet's Clay

Researchers propose that Mars' early thick atmosphere was absorbed by clay minerals, storing carbon dioxide as methane.

A new study suggests that Mars' thick early atmosphere could be sequestered in the planet's clay-rich crust.
Researchers at MIT found that interactions between water and certain rock types on Mars could have trapped carbon dioxide as methane in clays.
The process, similar to those observed on Earth, may explain where Mars' atmosphere went billions of years ago.
The team used models based on Earth's geology to estimate that up to 80% of Mars' initial atmosphere could be locked in clay minerals.
This trapped methane could potentially be harnessed as an energy source for future Mars missions.