|Image credit: NASA/JPL-Caltech/MSSS|
While satellite images have always indicated that there may have been water at some point, Curiosity has now confirmed that this is true with images of a dried up stream in the Gale Crater. Not only would this have been a channel for flowing water, but it would have also been relatively deep, about hip height.
"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," said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. "Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we're actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it."
The discovery was made with the analysis of two outcrops, "Hottah" and "Link", which contain rounded and angular gravel. The nature of the gravel led scientists to suspect that it must have been transported from one location to another, but not by wind. Because it was most likely water, and the region contains clay and sulfate minerals, there's a good chance that the planet once harboured organic life.
"A long-flowing stream can be a habitable environment," said Grotzinger. "It is not our top choice as an environment for preservation of organics, though. We're still going to Mount Sharp, but this is insurance that we have already found our first potentially habitable environment."
In the future, the little Mars robot that could will examine the environment around the Gale Crater to find out whether this could have been a place where life once flourished.
Via [NASA JPL Blog]