NASA’s Mars Curiosity has found a 3.7 billion year old lake that could be a clue to whether Mars could have truly supported life.

The lake is younger than scientists previously believed, indicating that life could have existed on Mars much more “recently” than assumed. The lake is “very Earth-like” according to NASA’s Curiosity lead scientist John Grotzinger, speaking with

The lake spans 30 miles in length and around three miles in width and might have been formed by streams running down from mountains into an alluvial fan.

“That probably was not unlike what happened during the last glacial maximum in the Western U.S.,” said Grotzinger.

Curiosity is a vehicle-sized rover that landed on Mars’ surface a year ago after the “seven minutes of terror” — or the intensive, relatively untested, landing procedure that had a seven minute delay between landing and relaying back to Earth whether it was a success or not. The rover has since been exploring Mars’ surface, testing regolith samples and delivering new information about the red planet’s surface back to NASA engineers.

In March, Curiosity found further evidence that water¬†was once present on Mars’ surface near Curiosity’s landing site in a place called Yellowknife Bay. The rover discovered that water molecules were bound to other minerals in the rocks on Mars. Curiosity used a “neutron gun” to determine this.

NASA says this is proof that Mars “was indeed habitable billions of years ago.”

It has not, however, been proven that any life forms existed on the planet.