New research suggests the atmosphere of Mars may be hiding in plain sight, having been absorbed by minerals in the Red Planet's clays. If Mars' envelope of gas did "go to ground" over 3 billion years ago, this could explain how Earth's neighboring planet became so different from our world, potentially losing its capability to host life.
Scientists know that the Red Planet wasn't always the arid and barren landscape that the Mars rovers Perseverance and Curiosity trundle across today. Both of NASA's rolling robots have uncovered evidence that abundant water flowed over Mars early in its 4.6 billion-year history. But for Mars to have had liquid water, it must also have possessed an atmosphere to stop this water from freezing. The big question for decades has been: where did this atmosphere go when disappeared?
