Is there life on Mars?

Conspicuously missing from the report¹ of a shallow, buried lake of liquid water on Mars, or from the accompanying commentary,² was any discussion of the astrobiological implications. This is probably as it should be: the result tells us nothing in itself about whether there is, or ever has been, life on Mars. But while planetary scientists have a host of good reasons to be interested in the hydrological past and present of the Red Planet that have nothing to do with putative martian life-forms, for the wider public that is the question looming over the search for water on Mars.