The rover looks for signs of ancient life inside a 45-kilometer-wide crater known as Lake Jezero.

The arid crater was once filled with water more than 3.5 billion years ago.

It is understood that the river delta flooded over the crater wall and scattered minerals and clays that might have captured and petrified ancient life.

The rover’s primary mission is to explore the crater and collect samples of rocks, dirt and other minerals for analysis.

Persistence caught “sharp” in the steep slopes that formed from sediment, accumulated at the mouth of the delta river and then spilled into the crater lake.

“We saw different layers in the sharps containing boulders up to 1.5 feet across, which we knew had nothing to do there,” said Nicolas Mangold, a scientific scientist from the Laboratoire de Planétologie et Géodynamique in Nantes, France.

The layers mean the slow, winding waterways that fed the delta river must have been transformed by later, rapidly moving floods.

Sir. Mangold and the science team estimated that a stream of water would have had to travel at speeds of 6 km / h to 30 km / h to transport the boulders.