Putative Paleolake

We may know Mars as the Red Planet, but many of the HiRise images are studies in blue. NASA titled this one "Putative Paleolake"--a name suggestive of the theory that liquid water once could be found on Mars.

The Mars Reconnaissance Orbiter has been circumnavigating its namesake planet since early 2006. It sent back its first high-resolution image in March of that year.