NASA’s Mars Reconnaissance Orbiter reveals that the Martian lakes and snowmelt-fed streams in the northern Arabia Terra region actually formed much later than we thought. Apparently, these topographical features are a billion years younger than other well-known ancient valley networks on Mars.

The findings, now in the journal Journal of Geophysical Research Planets, indicate that the Red Planet was still capable of sustaining microbial life at a later time. The data were taken by the Context Camera and High Resolution Imaging Science Experiment camera on the Mars Reconnaissance Orbiter as well as other information from the space agency’s Mars Global Surveyor and the European Space Agency’s Mars Express.

“We discovered valleys that carried water into lake basins,” points out Sharon Wilson, a researcher from the Smithsonian Institution, Washington and the University of Virginia, Charlottesville. “Several lake basins filled and overflowed, indicating there was a considerable amount of water on the landscape during this time.”

They also found a lake that can hold water comparable in volume to Lake Tahoe, which holds 45 cubic miles or 188 cubic kilometers of water. Previously, this Martian lake overflowed and carried water downstream in a massive basin called Heart Lake.

The chain of lakes and valleys of Heart Lake extend up to 150 kilometers. Overall, scientists estimate that this basin used to hold around 2,790 cubic kilometers of water, an amount greater than what Lake Ontario can hold.

The team believes that the wet period on Mars most likely happened between two and three billion years ago. This date was much later than the time previously believed the Red Planet lost its capability to sustain life and turned all of its remaining water into ice.

The features they found are actually not localized in the region but was actually present all over the planet. They also found similar valleys about 35 and 42 degrees latitude, both north and south of the Martian equator.