On the 39th Martian day of the Curiosity rover’s mission, it’s found evidence of a now-dried-up riverbed on Mars. The riverbed was found between the north rim of Gale Crater and the base of Mount Sharp. The rover is on its way to Mount Sharp, a location where NASA believes the rover holds a better chance of finding preserved organic material. Finding a spot where water likely flowed is a great sign.
The spot, nicknamed “Hottah”, contains something unique: gravel. The gravel ranges in size from as small as a grain of sand to as large as a golf ball, which is too large to have been transported by wind. Many of the rocks are rounded, suggesting they were worn down by long-flowing liquid. The large number of channels also suggests water was flowing there for many years.
This is the first time we’ve directly observed water-transported gravel on Mars. NASA scientist William Dietrich says, “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.” Now if you’ll excuse us, we have to put on our floaties and get our asses to Mars.
I’m not sure that’s really a picture of a riverbed on Earth. Where’s all the broken glass and used condoms?
[More pictures available at NASA (via Gizmodo). Banner picture made by Ed Yong.]