Ancient floods on Mars left their marks deeply etched into the planet’s surface. Canyons bigger than the Grand Canyon, dry riverbeds, deltas, and huge sandbars suggest to us that Mars had a lot of water and that it flowed with a vengeance. We see something amazingly similar in southeastern Washington, in the Channeled Scablands. Roy Torley takes you on a tour to do some interesting planetary geology on Earth and its sister planet, Mars.
