For the first time ever, people have drilled into a rock on Mars, collecting the powdered remains from the hole for analysis.
Images sent back from NASA's Mars rover Curiosity on Wednesday confirmed that the precious sample is being held by the rover's scoop, and will soon be delivered to two miniature chemical labs to undergo an unprecedented analysis. (Related: "Mars Rover Curiosity Completes First Full Drill.")
To the delight of the scientists, the rock powder has come up gray and not the ubiquitous red of the dust that covers the planet. The gray rock, they believe, holds a lot of potential to glean information about conditions on an early Mars. (See more Mars pictures.)
"We're drilling into rock that's a time capsule, rocks that are potentially ancient," said sampling-system scientist Joel Hurowitz during a teleconference from NASA's Jet Propulsion Laboratory in California.
A Place to Drill
The site features flat bedrock, often segmented into squares, with soil between the sections and many round gray nodules and white mineral veins.
Hurowitz said that the team did not attempt to drill into the minerals or the gray balls, but the nodules are so common that they likely hit some as they drilled down 2.5 inches (6.3 centimeters).
In keeping with the hypothesis that the area was once under water, Hurowitz said the sample "has the potential of telling us about multiple interactions of water and rock."
The drill, located at the end of a seven-foot (two-meter) arm, requires precision maneuvering in its placement and movement, and so its successful initial use was an exciting and welcome relief. The rover has been on Mars since August, and it took six months to find the right spot for that first drill. (Watch video of the Mars rover Curiosity.)
The flat drilling area is in the lower section of Yellowknife Bay, which Curiosity has been exploring for more than a month. What was previously identified by Curiosity scientists as the dry bed of a once flowing river or stream appears to fan out into the Yellowknife area.
The bedrock of the site—named after deceased Curiosity deputy project manager John Klein—is believed to be siltstone or mudstone. Scientists said the veins of white minerals are probably calcium sulfate or gypsum, but the gray nodules remain something of a mystery.
To the team that designed and operates the drill, the results were a triumph, as great as the much heralded landing of Curiosity on the red planet. With more than a hundred maneuvers in its repertoire, the drill is unique in its capabilities and complexities. (Watch video of Curiosity's "Seven Minutes of Terror.")
Sample system chief engineer Louise Jandura, who has worked on the drill for eight years, said the Curosity team had made eight different drills before settling on the one now on the rover. The team tested each drill by boring 1,200 holes on 20 types of rock on Earth.
She called the successful drilling "historic" because it gives scientists unprecedented access to material that has not been exposed to the intense weathering and radiation processes that affect the Martian surface.
The gray powder will be routed to the two most sophisticated instruments on Curiosity—the Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin).
SAM, the largest and most complex instrument onboard, operates with two ovens that can heat the sample up to 1,800°F (982°C), turning the elements and compounds in the rock into gases that can then be identified. SAM can also determine whether any carbon-based organic material is present.
Organics are the chemical building blocks of life on Earth. They are known to regularly land on Mars via meteorites and finer material that rains down on all planets.
But researchers suspect the intense radiation on the Martian surface destroys any organics on the surface. Scientists hope that organics within Martian rocks are protected from that radiation.
CheMin shoots an x-ray beam at its sample and can analyze the mineral content of the rock. Minerals provide a durable record of environmental conditions over the eons, including information about possible ingredients and energy sources for life.
Both SAM and CheMin received samples of sandy soil scooped from the nearby Rocknest outcrop in October. SAM identified organic material, but scientists are still trying to determine whether any of it is Martian or the byproduct of organics inadvertently brought to Mars by the rover. (See "Mars Rover Detects Simple Organic Compounds.")
In the next few days, CheMin will be the first to receive samples of the powdered rock, and then SAM. Given the complexity of the analysis, and the track record seen with other samples, it will likely be weeks before results are announced.
The process of drilling and collecting the results was delayed by several glitches that required study and work-arounds. One involved drill software and the other involved a test-bed problem with a sieve that is part of the process of delivering samples to the instruments.
Lead systems engineer Daniel Limonadi said that while there was no indication the sieve on Mars was malfunctioning, they had become more conservative in its use because of the test bed results. (Related: "A 2020 Rover Return to Mars?")
Author of the National Geographic e-book Mars Landing 2012, Marc Kaufman has been a journalist for more than 35 years, including the past 12 as a science and space writer, foreign correspondent, and editor for the Washington Post. He is also author of First Contact: Scientific Breakthroughs in the Hunt for Life Beyond Earth, published in 2011, and has spoken extensively to crowds across the United States and abroad about astrobiology. He lives outside Washington, D.C., with his wife, Lynn Litterine.