This image shows the central region of the Andromeda galaxy in X-rays, where the newly discovered ULX outshines all other sources. Image: Landessternwarte Tautenburg, XMM-Newton, MPE
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An ultraluminous x-ray source (ULX) previously spotted in the neighboring Andromeda galaxy by NASA’s Chandra observatory has now been revealed to be a stellar-mass black hole, according to researchers at the Max Planck Institute for Extraterrestrial Physics.
The black hole was the first ULX seen in Andromeda, as well as the closest ever observed.
Ultraluminous x-ray sources are rare objects, observed in the near and distant Universe in the outer regions of galaxies. Typically only one or two ULXs are seen in any one particular galaxy — if there are any seen at all.
The large distances to ULXs makes detailed observations difficult, and so their exact causes have been hard to nail down.
This particular x-ray source was first identified in late 2009 by Chandra and was followed up with observations by Swift and Hubble. Classified by researchers at the Max Planck Institute as a low-luminosity source, it actually outshined the entire Andromeda galaxy in x-ray luminosity!
Continued observations with Chandra and ESA’s XMM-Newton showed behavior similar to known x-ray sources in our own Milky Way galaxy: actively feeding black holes.
“We were very lucky that we caught the ULX early enough to see most of its lightcurve, which showed a very similar behavior to other X-ray sources from our own galaxy,” said Wolfgang Pietsch from the Max Planck Institute for Extraterrestrial Physics. The emission decayed exponentially with a characteristic timescale of about one month, which is a common property of stellar mass X-ray binaries. “This means that the ULX in Andromeda likely contains a normal, stellar black hole swallowing material at very high rates.”
It’s estimated that the black hole is at least 13 times the mass of the Sun.
Continued observations of the ULX/black hole will attempt to observe another outburst similar to the 2009 event, although if this black hole is anything like those observed in our galaxy it could be years before another such event occurs. Still, our relatively clear view of the Andromeda galaxy unobscured by intervening dust and gas offers a chance to perhaps spot other potential x-ray sources residing there.
Aurora seen in February 2012 from Skaftafell National Park in Iceland. Credit: Andrew Welstead
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From one hemisphere to another: Noel Welstead from Australia sent us a note that his son Andrew had traveled to Iceland this week, and one of his goals was to see if he could photograph the Northern Lights. Andrew was in the Skaftafell National Park, the south central part of Iceland when he took these stunning images. See more below.
Aurora seen in February 2012 from Skaftafell National Park in Iceland. Credit: Andrew WelsteadAurora seen in February 2012 from Skaftafell National Park in Iceland. Credit: Andrew Welstead
Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
Clouds over the southern Indian Ocean, July 23, 2007. (NASA/JPL-Caltech)
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Ok, maybe not the sky itself… but the clouds. According to recent research by climate scientists in New Zealand, global cloud heights have dropped.
Researchers at The University of Auckland have reported a decreasing trend in average global cloud heights from 2000 to 2010, based on data gathered by the Multi-angle Imaging SpectroRadiometer (MISR) on NASA’s Terra satellite. The change over the ten-year span was 30 to 40 meters (about 100 to 130 feet), and was mostly due to fewer clouds at higher altitudes.
It’s suspected that this may be indicative of some sort of atmospheric cooling mechanism in play that could help counteract global warming.
“This is the first time we have been able to accurately measure changes in global cloud height and, while the record is too short to be definitive, it provides just a hint that something quite important might be going on,” said lead researcher Professor Roger Davies.
A steady reduction in cloud heights could help the planet radiate heat into space, thus serving as a negative feedback in the global warming process. The exact cause of the drop in cloud altitude is not yet known, but it could reasonably be resulting from a change in circulation patterns that otherwise form high-altitude clouds.
Rendering of the Terra spacecraft. (NASA)
Cloud heights are just one of the many factors that affect climate, and until now have not been able to be measured globally over a long span of time.
“Clouds are one of the biggest uncertainties in our ability to predict future climate,” said Davies. “Cloud height is extremely difficult to model and therefore hasn’t been considered in models of future climate. For the first time we have been able to accurately measure the height of clouds on a global basis, and the challenge now will be to incorporate that information into climate models. It will provide a check on how well the models are doing, and may ultimately lead to better ones.”
While Terra data showed yearly variations in global cloud heights, the most extreme caused by El Niño and La Niña events in the Pacific, the overall trend for the years measured was a decrease.
Continuing research will be needed to determine future trends and how they may impact warming.
“If cloud heights come back up in the next ten years we would conclude that they are not slowing climate change,” Davies said. “But if they keep coming down it will be very significant.”
The team’s study was recently published in the journal Geophysical Research Letters.
Terra is a multi-national, multi-disciplinary mission involving partnerships with the aerospace agencies of Canada and Japan. An important part of NASA’s Science Mission, Terra is helping scientists around the world better understand and protect our home planet.
NASA's Spitzer Space Telescope has detected the solid form of buckyballs in space for the first time. To form a solid particle, the buckyballs must stack together like oranges in a crate, as shown in this illustration. Image credit: NASA/JPL-Caltech
Astronomers using data from NASA’s Spitzer Space Telescope have, for the first time, discovered buckyballs in a solid form in space. Prior to this discovery, the microscopic carbon spheres had been found only in gas form in the cosmos. The new work, led by Prof. Nye Evans of Keele University, appears in a paper in the journal Monthly Notices of the Royal Astronomical Society.
Formally named buckminsterfullerene, buckyballs are named after their resemblance to the late architect Buckminster Fuller’s geodesic domes. They are made up of 60 carbon molecules arranged into a hollow sphere like a football. Their unusual structure makes them ideal candidates for electrical and chemical applications on Earth, including superconducting materials, medicines, water purification and armour.
In the latest discovery, scientists using Spitzer detected tiny specks of matter, or particles, consisting of stacked buckyballs. They found the particles around a pair of stars called “XX Ophiuchi,” 6,500 light-years from Earth, and detected enough to fill the equivalent in volume to 10,000 Mount Everests.
“These buckyballs are stacked together to form a solid, like oranges in a crate,” said Prof. Evans. “The particles we detected are miniscule, far smaller than the width of a hair, but each one would contain stacks of millions of buckyballs.”
Buckyballs were detected definitively in space for the first time by Spitzer in 2010. Spitzer later identified the molecules in a host of different cosmic environments. It even found them in staggering quantities, the equivalent in mass to 15 Earth moons, in a nearby galaxy called the Small Magellanic Cloud.
In all of those cases, the molecules were in the form of gas. The recent discovery of buckyballs particles means that large quantities of these molecules must be present in some stellar environments in order to link up and form solid particles. The research team was able to identify the solid form of buckyballs in the Spitzer data because they emit light in a unique way that differs from the gaseous form.
“This exciting result suggests that buckyballs are even more widespread in space than the earlier Spitzer results showed,” said Mike Werner, project scientist for Spitzer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “They may be an important form of carbon, an essential building block for life, throughout the cosmos.”
Buckyballs have been found on Earth in various forms. They form as a gas from burning candles and exist as solids in certain types of rock, such as the mineral shungite found in Russia, and fulgurite, a glassy rock from Colorado that forms when lightning strikes the ground. In a test tube, the solids take on the form of dark, brown “goo.”
“The window Spitzer provides into the infrared universe has revealed beautiful structure on a cosmic scale,” said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. “In yet another surprise discovery from the mission, we’re lucky enough to see elegant structure at one of the smallest scales, teaching us about the internal architecture of existence.”
You can shelf your designs for a warp drive engine (for now) and put the DeLorean back in the garage; it turns out neutrinos may not have broken any cosmic speed limits after all.
Ever since the news came out on September 22 of last year that a team of researchers in Italy had clocked neutrinos traveling faster than the speed of light, the physics world has been resounding with the potential implications of such a discovery — that is, if it were true. The speed of light has been a key component of the standard model of physics for over a century, an Einstein-established limit that particles (even tricky neutrinos) weren’t supposed to be able to break, not even a little.
“According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos’ flight and an electronic card in a computer,” Cartlidge reported.
The original OPERA (Oscillation Project with Emulsion-tRacking Apparatus) experiment had a beam of neutrinos fired from CERN in Geneva, Switzerland, aimed at an underground detector array located 730 km away at the Gran Sasso facility, near L’Aquila, Italy. Researchers were surprised to discover the neutrinos arriving earlier than expected, by a difference of 60 nanoseconds. This would have meant the neutrinos had traveled faster than light speed to get there.
Repeated experiments at the facility revealed the same results. When the news was released, the findings seemed to be solid — from a methodological standpoint, anyway.
Shocked at their own results, the OPERA researchers were more than happy to have colleagues check their results, and welcomed other facilities to attempt the same experiment.
Repeated attempts may no longer be needed.
Once the aforementioned fiber optic cable was readjusted, it was found that the speed of data traveling through it matched the 60 nanosecond discrepancy initially attributed to the neutrinos. This could very well explain the subatomic particles’ apparent speed burst.
Case closed? Well… it is science, after all.
“New data,” Cartlidge added, “will be needed to confirm this hypothesis.”
UPDATE 2/22/12 11:48 pm EST: According to a more recent article on Nature’s newsblog, the Science Insider report erroneously attributed the 60 nanosecond discrepancy to loose fiber optic wiring from the GPS unit, based on inside “sources”. OPERA’s statement doesn’t specify as such, “saying instead that its two possible sources of error point in opposite directions and it is still working things out.”
OPERA’s official statement released today is as follows:
“The OPERA Collaboration, by continuing its campaign of verifications on the neutrino velocity measurement, has identified two issues that could significantly affect the reported result. The first one is linked to the oscillator used to produce the events time-stamps in between the GPS synchronizations. The second point is related to the connection of the optical fiber bringing the external GPS signal to the OPERA master clock.
These two issues can modify the neutrino time of flight in opposite directions. While continuing our investigations, in order to unambiguously quantify the effect on the observed result, the Collaboration is looking forward to performing a new measurement of the neutrino velocity as soon as a new bunched beam will be available in 2012. An extensive report on the above mentioned verifications and results will be shortly made available to the scientific committees and agencies.” (via Nature newsblog.)
These barchan (crescent-shaped) sand dunes are found within the North Polar region of Mars. Credit: NASA/JPL/University of Arizona
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Say the word “dunes” and the image that likely comes to mind is the sort of features you’d see in the Sahara Desert; huge mounds of carmel-colored shifting sand. But on Mars, dunes take on an entirely different connotation, and with the orbital eyes of the HiRISE camera on the Mars Reconnaissance Orbiter, we’ve seen some pretty bizarre-looking dunes. Take the image above for example, a newly released photo of well-speckled dunes in Mars’ north polar region. In this image, taken during the northern spring season, the dunes and ground are still covered in seasonal frost. “The speckled appearance is due to the warming of the area — as the carbon dioxide frost and ice on the dunes warms, small areas warm and sublimate (turn from solid to gas) faster, creating small jets that expose/deposit dark sand and dust onto the surface,” writes Serina Diniega on the HiRISE website. “Notice that there are no spots on the ground between the dunes — that is because the ground stays more uniformly cold, unlike the darker dune sand.”
See below for more weird dunes on Mars.
Dunes in Aonia Terra on Mars. Credit: NASA/JPL/University of Arizona
These dunes look as through someone has thrown a rippled blue-toned cloth across Mars’ surface. HiRISE is monitoring these dunes in Aonia Terra for changes such as gullies, which form over the winter from the action of carbon dioxide frost. This image was taken on January 18, 2012 here on Earth, but the season in on Mars where this was taken was late fall in the Southern hemisphere. “Frost is just starting to accumulate here, and is concentrated on pole-facing slopes and in the troughs between the meter-scale ripples,” wrote HiRISE Principal Investigator Alfred McEwen.
Dunes in Russell Crater Dunes on Mars. Credit: NASA/JPL/University of ArizonaPink dunes with black polka-dot speckles. Credit: NASA/JPL/University of ArizonaA wide area of dunes in Terra Cimmeria look as if they are being viewed under water. Credit: NASA/JPL/University of ArizonaFans and polygons on Dunes. Credit: NASA/JPL/University of ArizonaDark sand dunes at high Northern latitudes on Mars are covered seasonally by a layer of condensed carbon dioxide (dry ice), visible in this image. Credit: NASA/JPL/University of Arizona
Chocolate dunes? Credit: NASA/JPL/University of Arizona
Vesta's surface textures get highlighted by dawn's light
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Sunrise on Vesta highlights the asteroid’s varied surface textures in this image from NASA’s Dawn spacecraft, released on Monday, Feb. 20. The image was taken on Dec. 18 with Dawn’s Framing Camera (FC).
Just as the low angle of early morning sunlight casts long shadows on Earth, sunrise on Vesta has the same effect — although on Vesta it’s not trees and buildings that are being illuminated but rather deep craters and chains of pits!
The steep inner wall of a crater is seen at lower right with several landslides visible, its outer ridge cutting a sharp line.
Chains of pits are visible in the center of the view. These features are the result of ejected material from an impact that occurred outside of the image area.
Other lower-profile, likely older craters remain in shadow.
Many of these features would appear much less dramatic with a high angle of illumination, but they really shine brightest in dawn’s light.
A new look at old data has given scientists more insight into the Moon's core. Credit: Science
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Last year, scientists took another look at the seismic data collected by Apollo era experiments and discovered that the lower mantle of the Moon, the part near the core-mantle boundary, is partially molten (e.g., Apollo Data Retooled to Provide Precise Readings on Moon’s Core, Universe Today, Jan. 6, 2011). Their findings suggest that the lowest 150 km of the mantle contains anywhere from 5 to 30% liquid melt. On the Earth, this would be enough melt for it to separate from the solid, rise up, and erupt at the surface. We know that the Moon had volcanism in the past. So, why is this lunar melt not erupting at the surface today? New experimental studies on simulated lunar samples may provide the answers.
It is suspected that the current lunar magmas are too dense, in comparison to their surrounding rocks, to rise to the surface. Just like oil on water, less dense magmas are buoyant and will percolate up above the solid rock. But, if the magma is too dense, it will stay where it is, or even sink.
Motivated by this possibility, an international team of scientists, led by Mirjam van Kan Parker from the VU University Amsterdam, has been studying the character of lunar magmas. Their findings, which were recently published in the Journal Nature Geoscience, show that lunar magmas have a range of densities that are dependent on their composition.
Ms van Kan Parker and her team squeezed and heated molten samples of magma and then used X-ray absorption techniques to determine the material’s density at a range of pressures and temperatures. Their studies used simulated lunar materials, since lunar samples are considered too valuable for such destructive analysis. Their simulants modelled the composition of Apollo 15 green volcanic glasses (which have a titanium content of 0.23 weight %) and Apollo 14 black volcanic glasses (which have a titanium content of 16.4 weight %).
Samples of these simulants were subjected to pressures up to 1.7 GPa (atmospheric pressure, at the surface of the Earth, is 101 kPa, or 20,000 times less than what was achieved in these experiments). However, pressures in the lunar interior are even greater, exceeding 4.5 GPa. So, computer calculations were conducted to extrapolate from the experimental results.
Apollo 15 green glass beads. Credit: NASA
The combined work shows that, at the temperatures and pressures typically found in the lower lunar mantle, magmas with low titanium contents (Apollo 15 green glasses) have densities that are less than the surrounding solid material. This means they are buoyant, should rise to the surface, and erupt. On the other hand, magmas with high titanium contents (Apollo 14 black glasses) were found to have densities that are about equal to or greater than their surrounding solid material. These would not be expected to rise and erupt.
Since the Moon has no active volcanic activity, the melt currently located at the bottom of the lunar mantle must have a high density. And, Ms van Kan Parker’s results suggest that this melt should be made of high titanium magmas, like those that formed the Apollo 14 black glasses.
A new look at old data has given scientists more insight into the Moon's core. Credit: Science
This finding is significant, because high titanium magmas are thought to have formed from titanium-rich source rocks. These rocks represent the dregs that were left at the base of the lunar crust, after all the buoyant plagioclase minerals (which make up the crust) had been squeezed upwards in a global magma ocean. Being dense, these titanium-rich rocks would have quickly sunk to the core-mantle boundary in an overturn event. Such an overturn even had been postulated over 15 years ago. Now, these exciting new results provide experimental support for this model.
These dense, titanium-rich rocks are also expected to have a lot of radioactive elements, which tend to get left behind when other elements are preferentially taken up by mineral crystals. The resulting radiogenic heat from the decay of these elements could explain why parts of the lower lunar mantle are still hot enough to be molten. Ms van Kan Parker and her team further speculate that this radiogenic heat could also be helping to keep the lunar core partially melted even today!
Sources:
X-Rays Illuminate the Interior of the Moon, Science Daily, Feb. 19, 2012.
Neutral buoyancy of titanium-rich melts in the deep lunar interior, van Kan Parker et al. Nature Geoscience, Feb. 19, 2012, doi:10.1038/NGEO1402.
If you weren’t able to watch live, this is a fun exchange between the current astronauts in orbit, talking with one of the first people ever to see Earth from an orbital perspective. The astronauts aboard the International Space Station talked with Senator John Glenn during an in-flight call this week, to celebrate the 50th anniversary of Glenn’s historic Friendship 7 space flight. The event was part of NASA’s Future Forum at The Ohio State University in Columbus, Ohio.
Mosaic: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Kenneth Kremer
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Opportunity, the Princess of Martian Robots, phoned home dusty new self portraits – above and below – of her beautiful bod basking in the utterly frigid sunshine during her 5th winter on the Red Planet whilst overlooking a humongous crater offering bountiful science.
NASA’s endearing robot is simultaneously carrying out an ambitious array of ground breaking science experiments this winter – providing insight into the mysterious nature of the Martian core – while sitting stationary until the energy augmenting rays of the springtime Sun shower down on Mars from the heavens above.
Opportunity’s current winter worksite is located at the rim of the vast crater named Endeavour, some 14 miles (22 kilometers) in diameter. The robot will remain parked for the winter on a slope at the north end of the crater rim segment called Cape York with an approximate 15-degree northerly tilt towards the life-giving sun to maximize solar energy production. The park-site is at an outcrop dubbed “Greeley Haven”, named in honor of Ronald Greeley, a beloved and recently deceased science team member.
The power killing dust buildup is readily apparent on the solar arrays and High Gain Antenna pictured in the new panoramic self-portraits of Opportunity’s wing-like deck. The red Martian dust also functions as a rather effective camouflage agent, sometimes blending the rover to near invisibility with the surface.
Dusty Mars Rover's Self-Portrait- Dec 2011
NASA's Mars Exploration Rover Opportunity shows dust accumulation on the rover's solar panels as the mission approached its fifth Martian winter at the rim of Endeavour Crater. Opportunity is located on the north-facing slope of a site called "Greeley Haven." This is a mosaic of images taken by Opportunity's panoramic camera (Pancam) during the 2,811th to 2,814th Martian days, or sols, of the rover's mission (Dec. 21 to Dec. 24, 2011). Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.
Indeed because Opportunity is covered with a thicker film of dust compared to her prior four Martian winters, the rover team was forced to employ the same “tilting” strategy they successfully used to keep her twin sister Spirit alive during her trio of Antarctic-like winters. This is the first winter that Opportunity did not have sufficient power to continue roving across the surface.
Since Opportunity is located just south of the Martian equator, the daylight hours for solar power generation are growing shorter until the southern Mars winter solstice occurs on March 30, 2012. As of mid- February 2012, the latest measure of solar array energy production was 274 watt-hours, compared to about 900 watt-hours at the start of the mission. See Solar Power energy graph below.
Power generation from the solar arrays has fluctuated up and down throughout Opportunity’s lifetime depending on when the completely unpredictable and fortuitous Martian wind storms chance by and miraculously clean the arrays of the rusty red dust.
Opportunity Rover Self-Portrait From 2007
Opportunity used its panoramic camera (Pancam) during the mission's sols 1282 and 1284 (Sept. 2 and Sept. 4, 2007) to take the images combined into this mosaic view of the rover. The downward-looking view omits the mast on which the camera is mounted.The deck panorama is presented in approximate true color, the camera team's best estimate of what the scene would look like if humans were there and able to see it with their own eyes.Credit: NASA/JPL-Caltech/Cornell
The rover science team is ingeniously using the lack of movement to their advantage and Opportunity is still vigorously hard at work doing breakthrough research each and every day.
From her stationary position, Opportunity is conducting her first ever radio science Doppler tracking measurements to support geo-dynamic investigations and to elucidate the unknown structure of the Martian interior and core. The team was eager for the long awaited chance to carry out the radio tracking experiment with the High Gain Antenna (HGA) and determine if Mars core is liquid or solid. Months of data collection are required while the rover stays stationary.
“This winter science campaign will feature two way radio tracking with Earth to determine the Martian spin axis dynamics – thus the interior structure, a long-neglected aspect of Mars,” Ray Arvidson told Universe Today. Arvidson, of Washington University in St. Louis, is the deputy rover Principal Investigator.
Opportunity has nearly finished snapping the 13 filter, 360 degree stereo Greeley” panorama. The rover deployed the robotic arm onto the surface of the “Amboy” outcrop to collect multi-sol integrations with the Mössbauer Spectrometer and the largest ever mosaic campaign using the Microscopic Imager.
“We’ll do good science while we’re at Greeley Haven. But as soon as we catch a wind gust or the seasons change, we’ll be on our way again,” Steve Squyres told Universe Today. Squyres, of Cornell University is the rover Science Principal Investigator
“The Martian southern winter solstice occurs at the end of March. A few months after that date we will drive her off the outcrop and further explore Cape York,” Arvidson told me
The team will drive Opportunity in search of further evidence of the gypsum mineral veins like “Homestake” – indicative of ancient water flow – previously discovered at Cape York. Thereafter they’ll rove further south to investigate deposits of phyllosilicates, the clay minerals which stem from an earlier epoch when liquid water flowed on Mars eons ago and perhaps may have been more favorable to sustaining life.
Graph shows Opportunity’s Solar power energy generation over the past 1000 Sols, or Martian Days, from Sol 1900 up to February 2012. Credit: NASA/JPL/Marco Di Lorenzo Mars from Earth on Feb 18, 2012 is nearly at opposition (occurs March 3) in this image taken using a Celestron 11 inch telescope in Leesburg, Florida. Astrophotographer Credit: Ernie Rossi
Opportunity is now well into her 9th year exploring hitherto unknown terrain on Mars, far exceeding anyone’s expectation. She landed inside a tiny crater on Jan. 24. 2004 for what was expected to be a mission of merely 90 Martian days, or Sols.
Today is Martian Sol 2873, that’s 32 times beyond the rover designers “warranty” for NASA’s Opportunity rover.
Altogether, Opportunity has journeyed more than 21 miles (34 kilometers) across the Red Planet’s surface, marking the first overland expedition on another Planet. See our route map below.
Opportunity Rover Traverse Map at Meridiani Planum on Mars - 2004 to 2012
Traverse map shows the 8 Year Journey of Opportunity from Eagle Crater landing site on Sol 1- Jan. 24, 2004 - to 5th Winter Haven worksite at Greeley Haven at Endeavour Crater rim in January 2012. Opportunity embarked on a crater tour and discovered bountiful evidence for the flow of liquid water on Mars billions of years ago. Endeavour Crater is 14 miles 22 kilometers) in diameter. Opportunity has driven more than 21 miles (34 km). Credit: NASA/JPL/Cornell/UA/Marco Di Lorenzo/Kenneth Kremer
Meanwhile, NASA’s Curiosity Mars Science Laboratory rover is rocketing through space and on course for a pinpoint touchdown inside the layered terrain of Gale Crater on August 6, 2012. Curiosity is now America’s last planned Mars rover following the cancellation of the joint NASA/ESA ExoMars rover mission in the Obama Administrations newly announced Fiscal 2013 NASA budget.
