Martian Lakes

The landing sites of the two most recent American Mars rovers are about 2300 miles apart — roughly the distance from Los Angeles to Washington, D.C. Yet the sites are a lot alike. Both are inside impact craters that formed at least three and a half billion years ago. And both craters once held lakes — potential homes for microscopic life.

Curiosity landed in Gale Crater, in 2012. The crater is almost a hundred miles across, with a central mountain that’s three and a half miles high.

Curiosity has found that water could have filled the crater several times in its early history. Some of the lakes could have lasted for millions of years. Eventually, though, Mars lost most of its atmosphere, and the water on its surface disappeared.

Perseverance landed in Jezero Crater, in 2021. It’s a little less than 30 miles in diameter. But it, too, could have been filled up several times, with some of the lakes possibly hundreds of feet deep. At least one of the lakes formed when a massive flood ripped through the crater’s rim. It created a large river delta that Perseverance continues to explore.

Neither rover has found evidence of life. But they’ve revealed that both craters could’ve had the right conditions for life — billions of years ago.

Look for Mars well to the upper right of the Moon at dawn tomorrow. It looks like a bright orange star. More about Mars tomorrow.

Script by Damond Benningfield