NASA's Curiosity rover has indeed found something in the Martian dirt. But so far, there's no definitive sign of the chemical ingredients necessary to support life.
A scoop of sandy soil analyzed by Curiosity's sophisticated chemistry laboratory contained water and a mix of chemicals, but not complex carbon-based molecules considered essential for life.
That the soil was not more hospitable did not surprise mission scientist Paul Mahaffy since radiation from space can destroy any carbon evidence.
"It's not unexpected necessarily," said Mahaffy of NASA's Goddard Space Flight Center, who is in charge of the chemistry experiments. "It's been exposed to the harsh Martian environment."
The latest findings were presented Monday at a meeting of the American Geophysical Union in San Francisco. The mission managed by the NASA Jet Propulsion Laboratory is trying to determine whether conditions on Mars could have been favourable for microbes when the red planet was warmer and wetter.
Hopes for a "Mars-shaking" discovery peaked two weeks ago after mission chief scientist John Grotzinger told National Public Radio: "This data is gonna be one for the history books. It's looking really good."
The Internet lit up with excitement. NASA later clarified that Grotzinger was referring generally to the mission and not a specific result. Days before the science gathering, the space agency sought to contain expectations and issued a statement insisting there'd be no big news.
So what did Curiosity find after baking the soil and analyzing the resulting gases?
Water, sulfur and perchlorate, a highly oxidizing salt that was also detected by one of NASA's previous spacecraft, the Phoenix lander, in the northern Martian latitudes.
"This is typical, ordinary Martian soil," said mission scientist Ralf Gellert of the University of Guelph in Canada.