04Dec2012

Curiosity Findings To Be Unveiled At Conference.

Two of Curiosity’s wheels, heavily soiled with reddish Martian dust. A total of six wheels have the tough task of enabling the rover’s two-year mission of exploration across the wide expanse of Gale Crater and the lower slopes of Aeolis Mons. Photo Credit: NASA

For those who were expecting confirmation of the discovery of little green men or Decepticons or even traces of microbial life, you will probably be disappointed.

After rampant (and viral) internet speculation, NASA is expected to make an announcement at noon EST today about the progress and scientific achievements of its Curiosity rover during this week’s Fall Meeting of the American Geophysical Union (AGU). The meeting, which begins today in San Francisco and runs through to Friday, will include the long-awaited Curiosity news conference which NASA describes as “an update about first use of the rover’s full array of analytical instruments to investigate a drift of sandy soil.” Officials at the Jet Propulsion Laboratory in Pasadena, Calif., have stressed that rumours about a dramatic new discovery “at this early stage are incorrect.”

Misread Quote?

The speculation arose in mid-November, when Curiosity’s chief scientist, John Grotzinger, was quoted as saying that the Sample Analysis at Mars (SAM) instrument had gathered data “for the history books.” Since SAM is designed to identify organic compounds in the Martian soil, it was assumed by many that the $2.5 billion, six-wheeled rover—which landed beside the 18,000-foot peak of Aeolis Mons (“Mount Sharp”) in the yawning bowl of 96-mile-wide Gale Crater in early August 2012—had uncovered traces of microbial life. That mistaken assumption was corrected by NASA officials last week: “At this point in the mission,” it was clarified on 29 November, “the instruments on the rover have not detected any definitive evidence of Martian organics.”

Worthwhile Mission

Yet Curiosity has made enormous inroads in our understanding of the nature of the Red Planet since touching down at a place now known as “Bradbury Landing”—in honour of the late science fiction writer Ray Bradbury—just one hundred and twenty days ago. It is barely a sixth of the way through its projected two-year primary mission to investigate whether the Gale Crater region was ever suitable to sustain microbial life. In fact, Mars’ close proximity to both our own planet and to the Sun has fuelled serious scientific discussion for more than a century that the blood-hued world may have produced organics at some stage. The possibility has inspired movies and books and posters and games and even today the lure of the planet remains inescapable.

Early view of Aeolis Mons (“Mount Sharp”), as imaged from Curiosity’s touchdown spot at the place now known as “Bradbury Landing”. Photo Credit: NASA

As early as the late 18th century, Mars’ polar ice caps were observed growing and shrinking with the onset of winter and summer in each hemisphere by William Herschel, and within a handful of decades the first suggestions were made that it may harbour seas, land, and possibly life. When Percival Lowell expressed his conviction that he had seen evidence of ancient canals on Mars, his adherents were captivated. Early spectroscopic observations of the Martian atmosphere seemed to reduce the likelihood of life, but that did nothing to dispel the excitement.

Radio Scare

H.G. Wells published his War of the Worlds in 1897, and Orson Welles’ famous—and famously terrifying—radio version in 1938 convinced many that not only was Mars inhabited, but it was inhabited by a hostile species.

Indeed, the planet has been hostile to many of our robotic emissaries, with fewer than half of all spacecraft successfully entering orbit or touching down safely on its red surface. When NASA’s Mariner 4 flew past Mars in July 1965, it revealed its truly arid nature, devoid of rivers or canals and with very little evidence of plate tectonics or weathering for at  least the last several billion years. A decade later, the Viking landers arrived and found no conclusive evidence for the existence of organic material in the soil.

Much later, in May-November 2008, the Phoenix lander revealed pH and salinity levels in the Martian north were relatively benign from a biological perspective, but that other aspects of the local geology made it somewhat less friendly to microbial life. Curiosity’s landing in August 2012 is expected to kick off a mission of at least two years to further investigate the possibility that evidence for the building blocks of life is entrenched within the Martian soil, awaiting discovery.

The barren landscape of Gale Crater offers little of a hospitable nature to Curiosity’s cameras, yet this desolate place may have been quite different in the distant geological past. Photo Credit: NASA

 One such building block has, and continues to be, the presence of water-ice in significant quantities.

Seeking The Water

Low atmospheric pressures and temperatures on the surface render it unlikely for anything capable of sustaining Earth-like life, although the discovery by Mars Express of water-ice reserves in the south pole in January 2004 and confirmation from the Opportunity rover the following March that Mars was, historically, a “wet” planet, lend credence to the possibility that conditions were more suitable in the distant past.

More recently, data from the Mars Global Surveyor suggested that water might occasionally flow on the surface, although this conclusion has been met with scepticism in some quarters of the scientific community.

Where To Now?

As for the future exploration of the Red Planet, funding presently hangs in the balance. Earlier this year, NASA budget cuts forced the space agency to cancel its involvement in the ExoMars mission with the European Space Agency, although several websites have noted a possibility that the forthcoming Space Launch System may be employed on a Mars Sample Return mission in the mid-2020s.

For now, however, we have the six wheels of Curiosity firmly planted in Gale Crater and after only four months on the surface, its Twitter feed already boasts 1.2 million followers and every report on its progress draws excited speculation. Even if today’s news conference reveals nothing more than a ho-hum update on its scientific progress, the prognosis for the remainder of its mission—and the chance of spectacular, ground-breaking discoveries—remains high. Source: Article originally appeared in AmericaSpace

 

NASA Mars Rover Fully Analyzes First Soil Samples

This is a view of the third (left) and fourth (right) trenches made by the 1.6-inch-wide (4-centimeter-wide) scoop on NASA's Mars rover Curiosity in October 2012.

This is a view of the third (left) and fourth (right) trenches made by the 1.6-inch-wide (4-centimeter-wide) scoop on NASA’s Mars rover Curiosity in October 2012. Image credit: NASA/JPL-Caltech/MSSS

NASA’s Mars Curiosity rover has used its full array of instruments to analyze Martian soil for the first time, and found a complex chemistry within the Martian soil. Water and sulfur and chlorine-containing substances, among other ingredients, showed up in samples Curiosity’s arm delivered to an analytical laboratory inside the rover.

Detection of the substances during this early phase of the mission demonstrates the laboratory’s capability to analyze diverse soil and rock samples over the next two years. Scientists also have been verifying the capabilities of the rover’s instruments.

Analysis begins

Curiosity is the first Mars rover able to scoop soil into analytical instruments. The specific soil sample came from a drift of windblown dust and sand called “Rocknest.” The site lies in a relatively flat part of Gale Crater still miles away from the rover’s main destination on the slope of a mountain called Mount Sharp. The rover’s laboratory includes the Sample Analysis at Mars (SAM) suite and the Chemistry and Mineralogy (CheMin) instrument. SAM used three methods to analyze gases given off from the dusty sand when it was heated in a tiny oven. One class of substances SAM checks for is organic compounds — carbon-containing chemicals that can be ingredients for life.

“We have no definitive detection of Martian organics at this point, but we will keep looking in the diverse environments of Gale Crater,” said SAM Principal Investigator Paul Mahaffy of NASA’s Goddard Space Flight Center in Greenbelt, Md.

Mosaic image of Mars as seen by Viking 1, 22 F...

Mosaic image of Mars as seen by Viking 1, 22 February 1980 (Photo credit: Wikipedia)

Curiosity’s APXS instrument and the Mars Hand Lens Imager (MAHLI) camera on the rover’s arm confirmed Rocknest has chemical-element composition and textural appearance similar to sites visited by earlier NASA Mars rovers Pathfinder, Spirit and Opportunity.

Sifting Sand

Curiosity’s team selected Rocknest as the first scooping site because it has fine sand particles suited for scrubbing interior surfaces of the arm’s sample-handling chambers. Sand was vibrated inside the chambers to remove residue from Earth. MAHLI close-up images of Rocknest show a dust-coated crust one or two sand grains thick, covering dark, finer sand.

“Active drifts on Mars look darker on the surface,” said MAHLI Principal Investigator Ken Edgett, of Malin Space Science Systems in San Diego. “This is an older drift that has had time to be inactive, letting the crust form and dust accumulate on it.”

CheMin’s examination of Rocknest samples found the composition is about half common volcanic minerals and half non-crystalline materials such as glass. SAM added information about ingredients present in much lower concentrations and about ratios of isotopes. Isotopes are different forms of the same element and can provide clues about environmental changes. The water seen by SAM does not mean the drift was wet. Water molecules bound to grains of sand or dust are not unusual, but the quantity seen was higher than anticipated.

Contaminated sample?

SAM tentatively identified the oxygen and chlorine compound perchlorate. This is a reactive chemical previously found in arctic Martian soil by NASA’s Phoenix Lander. Reactions with other chemicals heated in SAM formed chlorinated methane compounds — one-carbon organics that were detected by the instrument. The chlorine is of Martian origin, but it is possible the carbon may be of Earth origin, carried by Curiosity and detected by SAM’s high sensitivity design.

“We used almost every part of our science payload examining this drift,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology in Pasadena. “The synergies of the instruments and richness of the data sets give us great promise for using them at the mission’s main science destination on Mount Sharp.”

NASA’s Mars Science Laboratory Project is using Curiosity to assess whether areas inside Gale Crater ever offered a habitable environment for microbes. NASA’s Jet Propulsion Laboratory in Pasadena, a division of Caltech, manages the project for NASA’s Science Mission Directorate in Washington, and built Curiosity.

Source: NASA. For more information about Curiosity and other Mars missions, visit: http://www.nasa.gov/mars .