The floods resulted from crater breaches that created deep rivers on the Red Planet's surface like the "Grand Canyon of Mars" Loire Vallis, new research shows.
Researchers who suggest Mars' size could explain why it lost its water are the latest team to consider how Earth's neighbor became the Red Planet.
These images are as close as any of us are getting to Mars any time soon—but they're beautiful enough to be a worthy consolation prize.
Is the briny sludge teeming with tiny organisms?
And the ice formations would be ideal locations for finding life, if it exists.
The agency is set to announce details on Thursday at 2 p.m. ET.
Because Mars isn't geologically active, it could provide a window to the formation of life.
Experts say the recent discovery that liquid water may run on the Martian surface changes the conversation about the Red Planet's habitability.