Was This Once a River on Mars?
The Curiosity rover finds what could have been an ancient streambed on the Red Planet
The rover Curiosity, controlled by the U.S. space agency NASA, has found evidence of an ancient stream on Mars. In photos it snapped with its onboard camera, the rover shows two sites with rocks containing gravel like that of a streambed. The finding comes within the first 40 days of the rover’s arrival on the Martian surface.
Although researchers have previously found evidence of water on the Red Planet, this is the first time they’ve seen an indication of flowing water like a river or stream.
The discovery is a result of examining sections of streambed—named Hottah and Link—inside Gale Crater, a cavity that formed on Mars some 3.5 billion years ago. Both slabs contain rounded rocks that range in size from that of a sand grain to that of a golf ball.
By studying the shapes and sizes of the stones in the images, scientists have determined that the stream flowed rapidly several billion years ago.
“From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle- and hip-deep,” says Bill Dietrich, a professor of earth and planetary science at the University of California, Berkeley.
Photos can provide a lot of information, but to learn more about ancient Mars and its once-wet environment, scientists will use Curiosity’s onboard instruments to see if the planet and its waterways once supported life—a major focus of Curiosity’s mission on Mars.
“A long-flowing stream can be a habitable environment,” says John Grotzinger, professor of geology at California Institute of Technology. Scientists hope to find out whether this stream was just that by using Curiosity to study the material of the two slabs in finer detail, and search further for evidence of life.