Together with co-authors Andrew H. Knoll and Scott M. McLennan, Tosca analyzed salt deposits in four-billion-year-old Martian rock explored by NASA's Mars Exploration Rover, Opportunity, and by orbiting spacecraft. It was the Mars Rover whose reports back to Earth stoked excitement over water on the ancient surface of the Red Planet.
The new analysis suggests that even billions of years ago, when there was unquestionably some water on Mars, its salinity commonly exceeded the levels in which terrestrial life can arise, survive, or thrive.
Of course, if the life forms had a biology entirely unknown on Earth (which they don't rule out) ...
But actually, you know, all that salt is doubtless from astrobiologists crying over the news. Bet you didn't know that astrobiologists are highly emotional types.