More pictures from NASA's Mars Reconnaissance Orbiter (MRO) show more signs of abundant and flowing water on Mars... once upon a time. These new pictures, such as the one used by National Geographic in reporting this, show cracks on the Martian surface that look like aquifers.

Yeah, this adds to the body of evidence that Mars had water once, but what's new about this? Scientists are theorizing that the same cracks might exist underneath the surface of Mars. With this in mind we have the potential explanation for the signs of water erosion they saw back last year with the Mars Global Surveyor (MGS).

Now that water on Mars is somewhat established by the evidence, some NASA scientists are suggesting that the search for life on Mars should shift from the current strategy of looking in places where there are signs of water, to something more focused. One suggestion is to focus more intently on the geology of Mars, studying rocks to find signs of microbial activity there. They believe that these microbes could live by harnessing chemical energy from the rocks, as some Earth-bound bacteria do.