NASA Rover Finds Clues to Changes in Mars' Atmosphere

NASA's car-sized rover, Curiosity, has taken significant steps toward understanding how Mars may have lost much of its original atmosphere. Learning what happened to the Martian atmosphere will help scientists assess whether the planet ever was habitable. The present atmosphere of Mars is 100 times thinner than Earth's. A set of instruments aboard the rover has ingested and analyzed samples of the atmosphere collected near the "Rocknest" site in Gale Crater where the rover is stopped for research. Findings from the Sample Analysis at Mars (SAM) instruments suggest that loss of a fraction of the atmosphere, resulting from a physical process favoring retention of heavier isotopes of certain elements, has been a significant factor in the evolution of the planet. Isotopes are variants of the same element with different atomic weights. Initial SAM results show an increase of five percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed. These enriched ratios of heavier isotopes to lighter ones suggest the top of the atmosphere may have been lost to interplanetary space. Losses at the top of the atmosphere would deplete lighter isotopes. Isotopes of argon also show enrichment of the heavy isotope, matching previous estimates of atmosphere composition derived from studies of Martian meteorites on Earth. Scientists theorize that in Mars' distant past its environment may have been quite different, with persistent water and a thicker atmosphere. NASA's Mars Atmosphere and Volatile Evolution, or MAVEN, mission will investigate possible losses from the upper atmosphere when it arrives at Mars in 2014. With these initial sniffs of Martian atmosphere, SAM also made the most sensitive measurements ever to search for methane gas on Mars. Preliminary results reveal little to no methane. Methane is of interest as a simple precursor chemical for life. On Earth, it can be produced by either biological or non-biological processes. Methane has been difficult to detect from Earth or the current generation of Mars orbiters because the gas exists on Mars only in traces, if at all. The Tunable Laser Spectrometer (TLS) in SAM provides the first search conducted within the Martian atmosphere for this molecule. The initial SAM measurements place an upper limit of just a few parts methane per billion parts of Martian atmosphere, by volume, with enough uncertainty that the amount could be zero. "Methane is clearly not an abundant gas at the Gale Crater site, if it is there at all. At this point in the mission we're just excited to be searching for it," said SAM TLS lead Chris Webster of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "While we determine upper limits on low values, atmospheric variability in the Martian atmosphere could yet hold surprises for us." In Curiosity's first three months on Mars, SAM has analyzed atmosphere samples with two laboratory methods. One is a mass spectrometer investigating the full range of atmospheric gases. The other, TLS, has focused on carbon dioxide and methane. During its two-year prime mission, the rover also will use an instrument called a gas chromatograph that separates and identifies gases. The instrument also will analyze samples of soil and rock, as well as more atmosphere samples. "With these first atmospheric measurements we already can see the power of having a complex chemical laboratory like SAM on the surface of Mars," said SAM Principal Investigator Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Md. "Both atmospheric and solid sample analyses are crucial for understanding Mars' habitability." SAM is set to analyze its first solid sample in the coming weeks, beginning the search for organic compounds in the rocks and soils of Gale Crater. Analyzing water-bearing minerals and searching for and analyzing carbonates are high priorities for upcoming SAM solid sample analyses. Researchers are using Curiosity's 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life. JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate, Washington, and built Curiosity. The SAM instrument was developed at Goddard with instrument contributions from Goddard, JPL and the University of Paris in France. For more information about Curiosity and its mission, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl . You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .

NASA Mars Rover Opportunity Reveals Geological Mystery: Spherical Objects Unlike Previously Found 'Blueberries'

NASA's long-lived rover Opportunity has returned an image of the Martian surface that is puzzling researchers. Exploration of Mars Spherical objects concentrated at an outcrop Opportunity reached last week differ in several ways from iron-rich spherules nicknamed "blueberries" the rover found at its landing site in early 2004 and at many other locations to date. Opportunity is investigating an outcrop called Kirkwood in the Cape York segment of the western rim of Endeavour Crater. The spheres measure as much as one-eighth of an inch (3 millimeters) in diameter. The analysis is still preliminary, but it indicates that these spheres do not have the high iron content of Martian blueberries. "This is one of the most extraordinary pictures from the whole mission," said Opportunity's principal investigator, Steve Squyres of Cornell University in Ithaca, N.Y. "Kirkwood is chock full of a dense accumulation of these small spherical objects. Of course, we immediately thought of the blueberries, but this is something different. We never have seen such a dense accumulation of spherules in a rock outcrop on Mars." The Martian blueberries found elsewhere by Opportunity are concretions formed by action of mineral-laden water inside rocks, evidence of a wet environment on early Mars. Concretions result when minerals precipitate out of water to become hard masses inside sedimentary rocks. Many of the Kirkwood spheres are broken and eroded by the wind. Where wind has partially etched them away, a concentric structure is evident. Opportunity used the microscopic imager its arm to look closely at Kirkwood. Researchers checked the spheres' composition by using an instrument called the Alpha Particle X-Ray Spectrometer on Opportunity's arm. "They seem to be crunchy on the outside, and softer in the middle," Squyres said. "They are different in concentration. They are different in structure. They are different in composition. They are different in distribution. So, we have a wonderful geological puzzle in front of us. We have multiple working hypotheses, and we have no favorite hypothesis at this time. It's going to take a while to work this out, so the thing to do now is keep an open mind and let the rocks do the talking." Just past Kirkwood lies another science target area for Opportunity. The location is an extensive pale-toned outcrop in an area of Cape York where observations from orbit have detected signs of clay minerals. That may be the rover's next study site after Kirkwood. Four years ago, Opportunity departed Victoria Crater, which it had investigated for two years, to reach different types of geological evidence at the rim of the much larger Endeavour Crater. The rover's energy levels are favorable for the investigations. Spring equinox comes this month to Mars' southern hemisphere, so the amount of sunshine for solar power will continue increasing for months. "The rover is in very good health considering its 8-1/2 years of hard work on the surface of Mars," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Energy production levels are comparable to what they were a full Martian year ago, and we are looking forward to productive spring and summer seasons of exploration." NASA launched the Mars rovers Spirit and Opportunity in the summer of 2003, and both completed their three-month prime missions in April 2004. They continued bonus, extended missions for years. Spirit finished communicating with Earth in March 2010. The rovers have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. JPL manages the Mars Exploration Rover Project for NASA's Science Mission Directorate in Washington. To view the image of the area, visit: http://www.nasa.gov/mission_pages/mer/multimedia/pia16139.html

NASA's new Mars picture

The US space agency NASA has recently pieced together a panoramic view from the camera on NASA's Mars Exploration Rover Opportunity, calling it the "next best thing to being" on the Red Planet. Here's The Most Stunning Photo of Mars The World Has Ever Seen A TextureCam analysis of a Mars image is able to distinguish rocks from soil. Future Planetary Rovers May Make Their Own Decisions In this undated image provided by NASA, Mars Rover Opportunity catches its own late-afternoon shadow in a view eastward across Endeavour Crater on Mars. The rover used a panoramic camera between about 4:30 and 5:00 p.m. local Mars time to record images taken through different filters and combined into this mosaic view. Most of the component images were recorded during the 2,888th Martian day, or sol, of Opportunity's work on Mars, which corresponds to March 9, 2012 on Earth. The view is presented in false color to make some differences between materials easier to see, such as the dark sandy ripples and dunes on the crater's distant floor. Opportunity has been studying the western rim of Endeavour Crater since arriving there in August 2011. In this undated image provided by NASA, Mars Rover Opportunity catches its own late-afternoon shadow in a view eastward across Endeavour Crater on Mars. The rover used a panoramic camera between about A close-up of the sunset on Sol 24 as seen by the Imager for Mars Pathfinder was released by the Jet Propulsion Labratory August 27. The red sky in the background and the blue around the Sun are approximately as they would appear to the human eye but the color of the Sun itself is not correct -- the Sun was overexposed in each of the 3 color images that were used to make the picture. The true color of the Sun itself may be near white or slightly bluish. Mars Mars A portion of the west rim of Endeavour crater sweeps southward in this color view from NASA's Mars Exploration Rover Opportunity released by NASA August 10, 2011. This crater has a diameter of about 14 miles (22 km). This view combines exposures taken by Opportunity's panoramic camera (Pancam) of the rover's work on Mars August 6, 2011. Opportunity arrived at the rim during its next drive on August 9, 2011. Endeavour crater has been the rover team's destination for Opportunity since the rover finished exploring Victoria crater in August 2008. Endeavour offers access to older geological deposits than any Opportunity has seen before. The lighter-toned rocks closer to the rover in this view are similar to the rocks Opportunity has driven over for most of the mission. However, the darker-toned and rougher rocks just beyond that might be a different type for Opportunity to investigate. The ground in the foreground is covered with iron-rich spherules, nicknamed "blueberries," which Opportunity has observed frequently since the first days after landing. They are about 0.2 inch (5 millimeters) or more in diameter. REUTERS/NASA/JPL-Caltech/Cornell/ASU/Handout (UNITED STATES - Tags: SCI TECH) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS

Helioshere-Sun Is Moving Slower Than Thought

Andrew Fazekas for NG News Published May 10, 2012 The sun is moving through the Milky Way slower than previously thought, according to new data from a NASA spacecraft. From its orbit around Earth, the Interstellar Boundary Explorer (IBEX) satellite measured the speeds of interstellar particles entering at the fringes of our solar system, 9 billion miles (14.5 billion kilometers) from the sun. Plugging the new data into computer models, the IBEX team calculates that the sun is moving at about 52,000 miles (83,700 kilometers) an hour—about 7,000 miles (11,000 kilometers) slower than thought. The discovery suggests that the protective boundary separating our solar system from the rest of the galaxy is missing a bow shock, a major structural component thought to control the influx of high-energy cosmic rays. The sun is constantly sending out charged particles in all directions, forming a cocoon around the solar system called the heliosphere. Like a boat moving through water, it's long been thought that the "bow" of the heliosphere forms a crescent-shaped shockwave as our solar system plows through the surrounding cloud of interstellar gas. (See "Solar System's 'Nose' Found; Aimed at Constellation Scorpius.") But the new IBEX findings mean the sun is moving so slow that pressure from material flowing around the heliosphere is 25 percent lower than expected—not enough for a bow shock. Until now, "all the solar system models and theories included a bow shock," said study leader David McComas of the Southwest Research Institute in San Antonio, Texas. "Having learned for nearly three decades about it, I was literally shocked when we found it was missing." Cosmic-Ray Shielding Key for Life? The absence of a bow shock is significant, McComas said, because it may indicate that the heliosphere is actually more robust than thought. With less pressure from outside material, the boundary region isn't being compressed and therefore weakened as much as expected, which means it should better repel cosmic rays. And understanding exactly how the heliosphere acts as a gatekeeper for cosmic rays could help scientists evaluate the chances for life on other worlds. According to McComas, some researchers believe that the cosmic rays that do get through the heliosphere can impact Earth's climate, because the high-energy particles can ionize—or electrically charge—matter in the atmosphere, leading to heightened cloud formation and lightning generation. Other experts think the particles could even be related to bursts of evolution or extinction in our planet's history, because the radiation can influence DNA patterns. For now, the science behind how cosmic rays have influenced Earth is quite controversial, said Seth Redfield, an astronomer from Wesleyan University in Connecticut who was not involved with the new IBEX study. Still, considering the rays' expected effects, Redfield said, "it seems obvious to me that there will be scenarios or times when the cosmic-ray flux on a planet is important and [is] having a major influence on the evolution of the planetary atmosphere or even on biological processes on its surface." In that case, astronomers assessing the habitability of alien planets may need to start considering not only the chances for liquid water but also the strength of other stars' protective cocoons, study leader McComas said. "There is no doubt," he said, "that questions about cosmic-ray shielding go right to the heart of some really important questions related to life as we know it." The slower-sun study appears in this week's issue of the journal Science.

Mysterious Geologic Structure Seen from Space

Dutch astronaut Andre Kuipers snapped this photo of a rock formation in Mauritania from the International Space Station. CREDIT: ESA/NASA



A huge, copper-toned formation in West Africa dominates a mesmerizing photo taken by an astronaut aboard the International Space Station.

Dutch astronaut Andre Kuipers snapped this hypnotic image of the so-called Richat structure in Mauritania, as the space station flew over the Sahara Desert on the Atlantic Coast of West Africa. Erosion of the various rock layers created the ring-like features that make up the sprawling structure, but the origin of the Richat structure remains somewhat mysterious, geologists have said.

The photo shows Kuipers' unique vantage point from the orbiting complex, which flies approximately 240 miles (386 kilometers) above the surface of the Earth. The image was taken on March 7 using a Nikon D2Xs camera, officials at the European Space Agency said in a statement.

During their months-long stints aboard the International Space Station, astronauts often perform Earth observations for science and public outreach.

Throughout their mission, many spaceflyers maintain active social media presences, such as on Twitter or Google+, to share stunning views from space with members of the public.

Space agencies also use photos taken by astronauts to engage students and space enthusiasts in geography, planetary science and human spaceflight.

There are currently six people living and working on the space station: Kuipers, Americans Dan Burbank and Don Pettit, and Russian cosmonauts Anton Shkaplerov, Anatoly Ivanishin and Oleg Kononenko. Burbank is commander of the station's Expedition 30 mission.

Kuipers launched to the space station in December 2011. He is almost midway through his six-month stay at the orbiting outpost. Kuipers, Kononenko and Pettit are slated to return to Earth on July 1.

Editor's Note: This story was updated to reflect that the Richat structure in Mauritania is not a lava crater.This story was provided by OurAmazingPlanet, sister site to SPACE.com. Follow OurAmazingPlanet for the latest in Earth science and exploration news on Twitter @OAPlanet and on Facebook

New Mars samples 'unlike any seen before'

A new site being explored by the Mars rover Opportunity has yielded soil samples unlike any examined before on the red planet and that appear more favorable for life, scientists said.

Opportunity, the indefatigable robot that has been exploring Mars for seven and a half years, arrived three weeks ago at the edge of a 22 kilometer (13.6 mile) wide crater named Endeavour and has been sending back images of the surrounding environment.

The first rock it examined is a flat-topped object about the size of a foot stool that apparently was cast up by an impact that left an impression the size of a tennis court on the rim of the crater.

Called Tisdale 2, the rock "is different from any rock we've ever seen on Mars," said Steve Squyres, a Cornell University scientist who is the principal investigator for Opportunity.

"It has a composition similar to some volcanic rocks, but there's much more zinc and bromine than we've typically seen," he said at a news conference.

The observations and measurements taken by the American Martian orbiters leads scientists to believe that the rocks on the rim of the crater contain clay minerals that form in wet conditions and which are less acidic and possibly more favorable for life, they said.

A bench around the edge of the crater resembles sedimentary rock that has been cut and filled with veins of material possibly left there by water, said Ray Arvidson, another member of the team who is from Washington University in St Louis, Missouri.

During the past two weeks, researchers have used an instrument attached to Opportunity's robot arm to identify the elements that make up the rock.