WASHINGTON  -    Mars looks like a dusty, dead, dry, boring planet. But science says otherwise. Science says that Mars used to be wet and warm, with an atmosphere. And science says that it was wet and warm for billions of years, easily long enough for life to appear and develop.

The scientific effort to understand Mars and its ancient habitability has really ramped up in recent years. Now that Spirit and Opportunity are gone, MSL Curiosity is carrying the workload. (NASA’s InSight lander is on Mars too, but it’s not looking for evidence of life or habitability.)

MSL Curiosity is driving around Gale Crater, looking for evidence that life lived there billions of years ago. Gale Crater is a dried up lake bed, and according to scientists, that’s the prime location to look for evidence.

Christopher House is a Professor of Geosciences at Penn State University. He’s also a participating scientist with NASA’s Mars Science Laboratory mission. In a press release from Penn State University, House talked about the MSL mission and what it’s like to be involved on a daily basis with the ground-breaking mission. “Gale Crater appears to have been a lake environment,” House said, adding that the mission has found a lot of finely layered mudstone in the crater.

“The water would have persisted for a million years or more.”

Gale Crater was chosen as the target for Curiosity because it’s a complex place. Not only was it a lake bed, meaning there are minerals there that can yield clues to Martian habitability, but that lake was eventually filled with sediment.

That sediment turned to stone, which then eroded. That same process is what created Mt. Sharp, the mountain in the middle of Gale Crater, and another of Curiosity’s objects of fascination.

“But the whole system, including the groundwater that ran through it, lasted much longer, perhaps even a billion or more years,” he said.