Mars flood channels were revealed by NASA using a radar on the Reconnaissance Orbiter (MRO). The channels are underground and could point to ancient mega-flood episodes.
The MRO used a ground-piercing radar sensor to capture images, which were turned into 3-D maps by a team of scientists. They focused on an equatorial region called Elysium Planitia, as well as the channels that run underneath the plains.
Lead researcher Gareth Morgan with the Smithsonian Institution explained that the contributions of rovers and landers have helped understand Mars some, but that “our view of the red planet has largely been restricted to looking at the surface.”
The first evidence of underground flood channels could help illuminate the role of water in Mars‘ history. The research offers a new perspective to Mars, whose surface already shows some evidence of past flooding, though the planet appears now to be cold and desert-like.
The channels are instrumental to understanding the extent to which flooding may have happened on Mars. The channels also help scientists understand whether floods could have induced climate change on the Red Planet. The estimated size of the Mars flooding is comparable to the ancient mega-flood in eastern Washington.
The flood in the Pacific Northwest created the Channeled Scablands, including the Columbia River Gorge. Morgan explained of the group’s findings:
“Our findings show the scale of erosion that created the channels previously was underestimated and the channel depth was at least twice that of previous approximations. This work demonstrates the importance of orbital sounding radar in understanding how water has shaped the surface of Mars.”
The team used the Mars Reconnaissance Orbiter’s Shallow Radar (SHARAD) to map the length, width, and depth of the underground channels. The scientists were able to find evidence that suggests two different phases of channel formation. This could mean that there were two separate mega-floods that hit Mars.
The scientists’ mapping also showed that the floods came from a now-buried portion of the Cerberus Fossae fracture system. The water may have accumulated underground and been released by tectonic or volcanic activity.