I’m on the road again, with less-than-stellar Internet access, but here goes. Malin Space Science Systems posted a page on Cantauri Crater and another on Sirenum Crater, both of which show evidence that suggests water flowed on Mars within the last decade—in not just one but two locations! A NASA press release also describes the findings.
It’s hard to come up with a better example of a picture being worth a thousand words, because the pair of images above make the story quite clear. The light-colored gully just looks like what planetary geologists suggest that it is. N.B., however, that the later image was taken in 2005. It’s not like they downloaded the data from the Mars Global Surveyor and posted them the next day! The science team went back and observed the same features over a period of a year, under a variety of lighting conditions, in order to make sure they weren’t falling victim to a trick of light.
So with the clarity comes a caveat: the picture may tell a story in and of itself, but good researchers don’t rely on a single image to form their results.