Wait, There's More: Curiosity Confirms Organics on Mars

NASA’s rover Curiosity has found organic compounds on Mars, the first definitive proof of building blocks for life on the Red Planet that also exist on Earth.

NASA's rover Curiosity has found organic compounds on Mars, the first definitive proof of materials on the Red Planet that, on Earth, are building blocks for life.

"We have had a major discovery. We have found organics on Mars," Curiosity lead scientist John Grotzinger, with the California Institute of Technology in Pasadena, Calif., said during a webcast press conference at the American Geophysical Union conference in San Francisco.

Whether the organics were delivered by carbon-rich meteorites or formed on Mars has yet to be determined.

PHOTOS: Curiosity Drills Mars Rock and Snaps Selfies

The discovery, paired with a sister investigation that found occasional spikes of methane gas in the Martian atmosphere, is a turning point for the mission, which began 2.5 years ago inside a 96-mile wide impact basin named Gale Crater.

On Earth, more than 90 percent of the atmospheric methane is produced by biological processes. The rest is tied to geochemical processes.

Mars missions used to be ones "where you observe and seek to explain, what I like to call the ‘Star Trek' mode -- build a spacecraft, go out there, find cool things that nobody saw before. Mars is now becoming a proving ground for a much more deductive line of science," Grotzinger said.

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Explaining both the organics and the methane will require far more analysis, much of which may be beyond the rover's capabilities. Both materials on Earth are tied to life, which may or may not prove to be true on Mars as well.

"We just have to respect that it is a possibility," Grotzinger said.

Curiosity got a taste of organics two years ago when it analyzed samples drilled out from an ancient mudstone called Cumberland, but scientists couldn't rule out until now that the carbon-containing compounds were hitchhikers from Earth.

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"It's not trivial to generate data like this in a laboratory, let alone on another planet," Curiosity participating scientist Roger Summons, with Massachusetts Institute of Technology, told reporters.

Organics, whether delivered by comets and asteroids crashing onto the surface or produced indigenously, face a tough life on Mars. The planet is constantly bombarded by cosmic rays, which destroy organics. Surface soils are strongly oxidizing, which break down molecular bonds. Perchlorates also produce chlorine, which change the molecules.

Curiosity scientists are mulling options to mitigate the effects of perchlorates in an effort to find not only more organics, but more complex molecules as well.

This image from the Mars Hand Lens Imager (MAHLI) camera on NASA's Curiosity Mars rover shows the first sample-collection hole drilled in Mount Sharp, the layered mountain that is the science destination of the rover's extended mission.

NASA's rover Curiosity has begun drilling operations for the third time on Mars. Currently located at a geologically interesting location nicknamed "The Kimberley," the one-ton rover also took the opportunity to photograph itself and the surrounding landscape in some stunning Martian "selfies." In this scene, Curiosity appears to be leaning its "head" -- a suite of instruments including the Chemcam (the laser "eye") and Mastcam cameras -- to the side, capturing the 5 kilometer-high Aeolis Mons (a.k.a. "Mount Sharp") on the horizon. The self portrait has been stitched together

by Discovery News' Jason Major

from a series of raw photographs (taken on sol 613, April 28, of the mission) by Curiosity's robotic arm-mounted Mars Hand Lens Imager (MAHLI) instrument.

In this scene, Curiosity appears to be concentrating hard on a rock of interest -- dubbed "Windjana" by mission scientists after a gorge in Western Australia -- that it has cleaned with its robotic arm-mounted Dust Abrasion Tool. A grey circular patch can be seen on the otherwise rusty rock's surface where the tool has scrubbed away any surface dust ready for analysis and drilling. This beautiful selfie was created

by JPL's Doug Ellison

, after assembling a collection of photos from the rover's Mars Hand Lens Imager (MAHLI) on sol 613 (April 28) of the mission. Curiosity's selfies not only produce some breathtaking scenes, they are also used by mission engineers to keep tabs on the condition of the rover the more time it is exposed to the harsh Martian environment.

Curiosity used its Mastcam to photograph this closeup of its Rock Abrasion Tool. The instrument spins the wire-bristle brush over rock surfaces to remove layers of dust that has accumulated.

After brushing, a grey circle of rock beneath the ruddy Mars dust is exposed for further analysis. In this photo by Curiosity's Mars Hand Lens Imager (MAHLI), the texture of Mars dust is obvious and fine cracks or seams in "Windjana" can be seen. "In the brushed spot, we can see that the rock is fine-grained, its true color is much grayer than the surface dust, and some portions of the rock are harder than others, creating the interesting bumpy textures,"

said Melissa Rice

, Curiosity science team member, of the California Institute of Technology, Pasadena. "All of these traits reinforce our interest in drilling here in order understand the chemistry of the fluids that bound these grains together to form the rock."

On April 29, Curiosity used its drill to bore a 2 centimeter hole into Windjana. This is only the third rock Curiosity has drilled into since landing on the red planet on Aug. 5, 2012. The grey color obviously extends deeper into the rock than just on its surface, and the powder created can provide a pristine rock sample for further analysis, helping mission scientists understand how the rock formed and under what environmental conditions.

The first two drilled rocks were located in Yellowknife Bay, approximately 4 kilometers from The Kimberley. Those rocks were determined to be mudstone slabs formed through water action and sediment, providing compelling evidence that the interior of Gale Crater used to play host to a lakebed and may have provided a habitable environment for ancient microbial life. This new drilling operation will provide more clues as to how rock formed in the region, revealing more tantalizing clues as to the past habitability of the red planet.