This image of NGC 6240 contains new X-ray data from Chandra (shown in red, orange, and yellow) that has been combined with an optical image from the Hubble Space Telescope originally released in 2008. In 2002, Chandra data led to the discovery of two merging black holes, which are a mere 3,000 light years apart. They are seen as the bright point-like sources in the middle of the image.

Scientists think these black holes are in such close proximity because they are in the midst of spiraling toward each other -- a process that began about 30 million years ago. It is estimated that they holes will eventually drift together and merge into a larger black hole some tens or hundreds of millions of years from now.

Finding and studying merging black holes has become a very active field of research in astrophysics. Since 2002, there has been intense interest in follow-up observations of NGC 6240, as well as a search for similar systems. Understanding what happens when these exotic objects interact with one another remains an intriguing question for scientists.

The formation of multiple systems of supermassive black holes should be common in the universe, since many galaxies undergo collisions and mergers with other galaxies, most of which contain supermassive black holes. It is thought that pairs of massive black holes can explain some of the unusual behavior seen by rapidly growing supermassive black holes, such as the distortion and bending seen in the powerful jets they produce. Also, pairs of massive black holes in the process of merging are expected to be the most powerful sources of gravitational waves in the Universe.

Labels: earth, nasa, reserach, sky, space

A successful NASA flight test Monday demonstrated how a spacecraft returning to Earth can use an inflatable heat shield to slow and protect itself as it enters the atmosphere at hypersonic speeds.

The Inflatable Re-entry Vehicle Experiment, or IRVE, was vacuum-packed into a 15-inch diameter payload "shroud" and launched on a small sounding rocket from NASA's Wallops Flight Facility on Wallops Island, Va., at 8:52 a.m. EDT. The 10-foot diameter heat shield, made of several layers of silicone-coated industrial fabric, inflated with nitrogen to a mushroom shape in space several minutes after liftoff.

The Black Brant 9 rocket took approximately four minutes to lift the experiment to an altitude of 131 miles. Less than a minute later it was released from its cover and started inflating on schedule at 124 miles up. The inflation of the shield took less than 90 seconds.

"Our inflation system, which is essentially a glorified scuba tank, worked flawlessly and so did the flexible aeroshell," said Neil Cheatwood, IRVE principal investigator and chief scientist for the Hypersonics Project at NASA's Langley Research Center in Hampton, Va. "We're really excited today because this is the first time anyone has successfully flown an inflatable reentry vehicle."

According to the cameras and sensors on board, the heat shield expanded to its full size and went into a high-speed free fall. The key focus of the research came about six and a half minutes into the flight, at an altitude of about 50 miles, when the aeroshell re-entered Earth's atmosphere and experienced its peak heating and pressure measurements for a period of about 30 seconds.

An on board telemetry system captured data from instruments during the test and broadcast the information to engineers on the ground in real time. The technology demonstrator splashed down and sank in the Atlantic Ocean about 90 miles east of Virginia's Wallops Island.

"This was a small-scale demonstrator," said Mary Beth Wusk, IRVE project manager, based at Langley. "Now that we've proven the concept, we'd like to build more advanced aeroshells capable of handling higher heat rates."

Inflatable heat shields hold promise for future planetary missions, according to researchers. To land more mass on Mars at higher surface elevations, for instance, mission planners need to maximize the drag area of the entry system. The larger the diameter of the aeroshell, the bigger the payload can be.

The Inflatable Re-entry Vehicle Experiment is an example of how NASA is using its aeronautics expertise to support the development of future spacecraft. The Fundamental Aeronautics Program within NASA's Aeronautics Research Mission Directorate in Washington funded the flight experiment as part of its hypersonic research effort.

For images and more information about the experiment, visit:

Labels: nasa, reserach, sky, space

Researchers conduct fieldwork to track permafrost melting in Alaska and gain insight about the release of carbon into the atmosphere

The terrain of the North Slope of Alaska is not steep, but Andrew Jacobson still has difficulty as he hikes along the spongy tundra, which is riddled with rocks and masks multitudes of mosquitoes.
Jacobson, a professor of earth and planetary sciences at Northwestern University, extracts soil and water samples in search of clues to one of global warming's biggest ticking time bombs: the melting of permafrost.
Permafrost, or frozen ground, covers approximately 20 to 25 percent of the land-surface area in the northern hemisphere, and is estimated to contain up to 1,600 gigatons of carbon, primarily in the form of organic matter. (One gigaton is equivalent to 1 billion tons.)
By comparison, the atmosphere now contains around 850 gigatons of the element as carbon dioxide.
"Permafrost historically has served as a carbon sink, largely isolating carbon from participating in the carbon cycle," says Jacobson, whose research is funded by the National Science Foundation (NSF) and the David and Lucile Packard Foundation. "However, global warming could transform the Arctic into a new carbon source by accelerating the rate of permafrost melting. This undoubtedly would have a dramatic effect on the global carbon cycle."
Jacobson says the key concern is that permafrost carbon will oxidize to carbon dioxide as melting accelerates, causing a positive feedback to global warming. A vicious cycle is created as a warmer climate facilitates more carbon release, which in turn favors more warming.
So Jacobson and his colleagues collect river water and soil samples near NSF's Toolik Long-Term Ecological Research station, approximately 250 kilometers (km)--155 miles--north of the Arctic Circle. The Dalton Highway--built as a supply road to support the Trans-Alaska Pipeline System--provides the only access to the site.
"Planning constitutes a large part of our day--looking at maps, figuring out where to go and how to get there," he laughs. "Fieldwork is typically fraught with vehicle problems, poor roads and bad weather. One thing you can always count on is that every expedition is exciting."
While a logical first step for modeling global warming is quantifying carbon flow, unresolved complexities surrounding the Arctic carbon cycle make it difficult to create models for that element.
Jacobson and his team take a complementary approach by analyzing naturally occurring isotopes of other elements, such as calcium and strontium, which track permafrost melting and therefore provide insight into carbon release.
Initial data show that rivers and permafrost have distinctly different calcium and strontium isotope compositions.
When permafrost thaws during the summer and melts into rivers, the rivers show calcium and strontium isotope compositions that approach those for permafrost. Jacobson hypothesizes that in a warmer world, the permafrost signature in rivers will be more pronounced for longer periods of time.
Changes in the isotope composition of rivers can relate to changes in the release of carbon. So the calcium and strontium isotope composition of Arctic rivers can track the impact of warming on permafrost stability and carbon dioxide release.
"The ultimate goal is to establish a baseline to which future changes can be compared," Jacobson says. "Several years from now, we can compare real changes to model predictions and improve our understanding of how the system works."
The sampling season lasts for only a short time when permafrost thaws in the spring until it refreezes in the fall. Although he visited Alaska in May and will return in October, Jacobson has a team of colleagues and students who will conduct fieldwork throughout the season and again next year. Samples are shipped from the field to Jacobson's laboratory in Evanston, Ill., where he analyzes them in the off-season.
He received NSF funding in 2007 to acquire a multi-collector thermal ionization mass spectrometer for measuring isotopes of calcium, strontium and other elements. Northwestern currently is building a state-of-the-art "metal free" clean laboratory that will house the instrument and support Jacobson's research.

Labels: earth, nasa, nsf, reserach

It began with a furrowed brow, a moment of puzzlement, quickly dismissed.




The date was July 19, 2009. Amateur astronomer Anthony Wesley was photographing Jupiter from his backyard observatory in Murrumbateman, Australia, when something odd caught his eye.



"My attention was fixed on the Great Red Spot, which was setting beautifully over Jupiter's horizon," recalls Wesley. "I almost didn't notice the dark blemish near Jupiter's south pole, and when I did, I put it out of my mind."



It's just another dark storm on Jupiter.



"That's what I thought at first, but something about the dark mark puzzled me, it didn't look right, and I couldn't stop stealing glances at it."







Above: South is up in this July 19th discovery image taken by Anthony Wesley using a 14.5-inch telescope in Murrumbateman, Australia. [more]



Slowly, Jupiter's rotation turned the blemish toward Earth, Wesley got a better look at it, and the truth struck him like a thunderbolt.



It was an impact mark. Something hit the giant planet!



"I had seen the scars caused by fragments of Comet Shoemaker-Levy 9 hitting Jupiter in 1994, so I knew what an impact looked like," he says. "After I'd convinced myself that this was real, I could hardly use the computer. My hands were shaking. It was quite unbelievable."



He quickly emailed his photos to friends and colleagues around the world, and within hours telescopes great and small were turning toward Jupiter to photograph the aftermath of a powerful collision.



"We believe it was a comet or asteroid measuring perhaps a few hundred meters wide," says Don Yeomans of NASA's Near-Earth Object Office at JPL. "If something of similar size hit Earth—we're talking about 2000 megatons of energy--there would be serious regional devastation or a tsunami if it hit the ocean."



In a stroke of luck almost as big as Wesley's, JPL astronomers Glenn Orton and Leigh Fletcher were already scheduled to observe Jupiter on July 20th, barely a day after impact, using NASA's Infra-red Telescope Facility (IRTF) atop Mauna Kea in Hawaii. The 3-meter telescope revealed a fresh cloud of debris about the size of Mars floating among Jupiter's clouds.



Above: An IRTF image of the Jupiter impact debris cloud on July 20, 2009. The cloud appears bright at this wavelength (2.12 microns) because particles in the cloud are reflecting infrared radiation from the sun, explains observer Glenn Orton. [more]



"The object, whatever it was, exploded in Jupiter's upper atmosphere," says Orton. "It blew itself to smithereens. What we're seeing now are bits and pieces of the impactor and possibly some strange aerosols formed by shock-chemistry during the impact."



On July 23rd, the Hubble Space Telescope took its first pictures of the blast site. Hubble was still undergoing checkout and calibration following the STS-125 servicing mission in May, but this event was too big to skip. Space Telescope Science Institute director Matt Mountain allocated emergency telescope time to a team of astronomers led by Heidi Hammel of the Space Science Institute in Boulder, Colorado.



As usual, Hubble photos stole the show. They revealed a swirling maelstrom of dark cindery debris jostling with natural storms near the top of Jupiter's atmosphere:




Above: A Hubble Space Telescope image of the Jupiter impact scar taken on July 23, 2009, taken using Hubble's new camera, the Wide Field Camera 3 (WFC3). [more]



"The debris cloud is lumpy because of atmospheric turbulence," explains planetary scientist Amy Simon-Miller of the Goddard Space Flight Center. "Polar winds blowing 25 m/s (~55 mph) are causing it to spread out and grow larger. This will make the cloud even easier to see through backyard telescopes."



Judging from the behavior of the Comet Shoemaker-Levy 9 impacts fifteen years ago, she estimates that the 'Wesley debris cloud' could remain visible for many weeks to come. Researchers will put the time to good use. Further studies of the cloud might yet reveal the great unknown:


What hit Jupiter?

"We just don't know," says Yeomans. "No one saw the object prior to impact."

Indeed, there was no warning. The object emerged from darkness, unknown and uncatalogued, and—wham!—before anyone could photograph the body intact, it had become a cloud of debris. (There is a lesson here for Earth, but that is another story.)

The cloud's chemical composition holds clues to the nature of the impactor. Orton says ground-based observers are now analyzing light reflected from the cloud to figure out what it is made of. "If the spectra contain signs of water, that would suggest an icy comet. Otherwise, it's probably a rocky or metallic asteroid."

Meanwhile, it's a big dark mystery—the kind that Wesley can't take his eyes off of. "I am still observing Jupiter almost every night using my 14.5 inch telescope," he says. "The cloud is expanding and taking on some interesting shapes."

"I wonder," he says, "what will happen next?"

Source: NASA

Labels: discover, jupitor, nasa, reserach, sky, space

Research and Evaluation on Education in Science and Engineering (REESE)

Labels: nasa, nsf, rare, reese, reserach, sky