The Chances of Life Being in Mars' History Just Got Better.

This image released by NASA shows the Curiosity rover holding a scoop of powdered rock on Mars. The rover recently drilled into a Martian rock for the first time and transferred a pinch of powder to its instruments to analyze the chemical makeup. Credit NASA

Mars's Gale Crater was habitable in its distant past, perhaps during the same period in which microbial life was establishing itself on Earth between 3 billion and 4 billion years ago.

The issue of habitability is "in the bag," said John Grotzinger, a planetary geologist at the California Institute of Technology in Pasadena, Calif., and the mission's lead scientist, during a press briefing announcing the results today, March 12, 2013.

The minerals in the tiny, gray, ground-rock sample exposed by Curiosity's drill speak of abundant standing water, conditions neither too acidic or too alkaline for life, and the minerals that would have provided a ready energy source for microbes, if any had been there.

The water in the Gale Crater  being explored by Curiosity would have been "so benign and supportive of life that probably if this water was around and you had been on the planet, you would have been able to drink it," Grotzinger said.   Did Mars ever host environments suitable for life?   Yes is the conclusion scientists have reached after NASA's Mars rover Curiosity analyzed the first sample ever culled from deep in a rock on another planet. Curiosity used a first-of-its-kind drill to extract the sample.