Martian Lake

The landing site of the Perseverance Mars rover could have been quite comfortable about three-and-a-half billion years ago. The rover discovered organic compounds — the chemical building blocks of life — in sediments in an ancient riverbed. The rock layers where the compounds were found suggest the environment would have been favorable for life.

Jezero Crater is 28 miles across. And in the distant past, it was filled with water. Scientists had expected it to be paved with layers of sediment, which form as rocks and grit in the water settle to the bottom and cement together. Instead, the rover’s instruments have found that most of the rock on the crater floor was formed by volcanic processes.

Sedimentary rocks do form the river delta, which was deposited when Mars was warmer and wetter than it is today. Analysis of rocks at a formation named Wildcat Ridge revealed the organic compounds.

Perseverance will spend many months examining the delta. And it’s storing samples of the sediments for return to Earth, where scientists can check more thoroughly for evidence of ancient life.

Mars is a stunner right now. It’s passing especially close to Earth, so it outshines everything that’s currently in the night sky except the Moon and the planet Jupiter. It looks like a brilliant orange star. It’s low in the east-northeast as the sky gets fully dark, and climbs high across the sky later on.

More about Mars tomorrow.

Script by Damond Benningfield