Dan Vergano, USA TODAY
NASA's Curiosity rover is ready to start drilling a "candy store" of Mars rocks, report mission scientists, looking for evidence of past watery habitable conditions on the Red Planet.
On its 158th Martian day, the $2.5 billion rover rests in the "Yellowknife Bay" basin inside Gale Crater on Mars, lined with layers of rock that may point to a watery ancient surface there. The nuclear-powered rover is a mobile lab designed to look for chemistry indicating habitability of Mars, past and present.
"We've let the scientists into a candy store," says Richard Cook of NASA's Jet Propulsion Laboratory in Pasadena, Calif., speaking at a Tuesday briefing.
Investigation of rock layers within the basin reveals veins of rock lacing the basin's sandstone floor, says mission science chief John Grotzinger of Caltech. Chemical analysis shows that the veins are made of calcium and sulfur left from water that once percolated through the rock. Other rock layers reveal the action of water currents piling up layers of sands in cross-bedded fashion at the site.
"Mars in this location was geologically active enough to create these rock layers, which is totally cool," says mission scientist R. Aileen Yingst of the Planetary Science Institute in Tucson.
Drilling should commence within two weeks at the Yellowknife site, revealing the chemistry of the water that once covered the locale and giving first indications of past habitable conditions there, notably signs of carbon compounds used in the chemistry of living things.
"When it comes to drilling, we are in a really scientifically sweet spot to do that," Grotzinger says. He says the rover team plans to investigate the base of a nearby mountain thought to be lined with clay layers also formed by water.