The first analysis of powder samples drilled out from the inside of once water-soaked rock shows Mars was a suitable place for microbial life to evolve, scientists with NASA’s Mars rover Curiosity mission said Tuesday.

Among the chemicals discovered inside the rock, called “John Klein,” were sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon, all key ingredients for life.

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The analysis showed that water which once soaked the rock had a neutral pH – not too acidic and not too salty.

The findings indicate that if organics were present, they could have been preserved. That assessment remains under way.

“The key thing here is this an environment a microbe could have lived in and might have even prospered in,” lead scientist John Grotzinger, with the California Institute of Technology, told reporters during a press conference at NASA headquarters in Washington, D.C., and on a conference call.

Scientists don’t know how old the rock is, nor how it formed, but they suspect it is at least 3 billion years old and that the site’s habitability period likely coincides within a couple of hundred million years of the first preserved record of  life on Earth.

PHOTOS: Curiosity Drills Hole Into Mars Rock

The chemical analysis, completed before a computer glitch suspended Curiosity science operations more than a week ago, shows that water was in the area, known as Yellowknife Bay, long enough for telltale clays and minerals to form, there was plenty of it for any micro-organisms to use, and that it was neutral and not too salty.

“We  have found a habitable environment  that is 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 told reporters.

Additional analysis of the drill sample is expected as the rover slowly returns to operations in the next few days. However, a second drill hole will have to wait until May due to an upcoming radio communications blockage when the sun comes between Earth and Mars.

The rover landed Aug. 6 inside a giant impact basin to assess if the planet most like Earth has or ever had the ingredients for life.

Image: This set of images compares rocks seen by NASA’s Opportunity rover and Curiosity rover at two different parts of Mars. On the left is ” Wopmay” rock, in Endurance Crater, Meridiani Planum, as studied by the Opportunity rover. On the right are the rocks of the “Sheepbed” unit in Yellowknife Bay, in Gale Crater, as seen by Curiosity — both rocks were formed in a wet environment. Credit: NASA/JPL-Caltech