Astronomers have found a new cosmic source for the same kind of water that appeared on Earth billions of years ago and created the oceans. The findings may help explain how Earth's surface ended up covered in water.

New measurements from the Herschel Space Observatory show that comet Hartley 2, which comes from the distant Kuiper Belt, contains water with the same chemical signature as Earth's oceans. This remote region of the solar system, some 30 to 50 times as far away as the distance between Earth and the sun, is home to icy, rocky bodies including Pluto, other dwarf planets and innumerable comets.

"Our results with Herschel suggest that comets could have played a major role in bringing vast amounts of water to an early Earth," said Dariusz Lis, senior research associate in physics at the California Institute of Technology in Pasadena and co-author of a new paper in the journal Nature, published online today, Oct. 5. "This finding substantially expands the reservoir of Earth ocean-like water in the solar system to now include icy bodies originating in the Kuiper Belt."

Scientists theorize Earth started out hot and dry, so that water critical for life must have been delivered millions of years later by asteroid and comet impacts. Until now, none of the comets previously studied contained water like Earth's. However, Herschel's observations of Hartley 2, the first in-depth look at water in a comet from the Kuiper Belt, paint a different picture.

Herschel peered into the comet's coma, or thin, gaseous atmosphere. The coma develops as frozen materials inside a comet vaporize while on approach to the sun. This glowing envelope surrounds the comet's "icy dirtball"-like core and streams behind the object in a characteristic tail.

Herschel detected the signature of vaporized water in this coma and, to the surprise of the scientists, Hartley 2 possessed half as much "heavy water" as other comets analyzed to date. In heavy water, one of the two normal hydrogen atoms has been replaced by the heavy hydrogen isotope known as deuterium. The ratio between heavy water and light, or regular, water in Hartley 2 is the same as the water on Earth's surface. The amount of heavy water in a comet is related to the environment where the comet formed.

By tracking the path of Hartley 2 as it swoops into Earth's neighborhood in the inner solar system every six-and-a-`half years, astronomers know that it comes from the Kuiper Belt. The five comets besides Hartley 2 whose heavy-water-to-regular-water ratios have been obtained all come from an even more distant region in the solar system called the Oort Cloud. This swarm of bodies, 10,000 times farther afield than the Kuiper Belt, is the wellspring for most documented comets.

Given the higher ratios of heavy water seen in Oort Cloud comets compared to Earth's oceans, astronomers had concluded that the contribution by comets to Earth's total water volume stood at approximately 10 percent. Asteroids, which are found mostly in a band between Mars and Jupiter but occasionally stray into Earth's vicinity, looked like the major depositors. The new results, however, point to Kuiper Belt comets having performed a previously underappreciated service in bearing water to Earth.

How these objects ever came to possess the telltale oceanic water is puzzling. Astronomers had expected Kuiper Belt comets to have even more heavy water than Oort Cloud comets because the latter are thought to have formed closer to the sun than those in the Kuiper Belt. Therefore, Oort Cloud bodies should have had less frozen heavy water locked in them prior to their ejection to the fringes as the solar system evolved.

"Our study indicates that our understanding of the distribution of the lightest elements and their isotopes, as well as the dynamics of the early solar system, is incomplete," said co-author Geoffrey Blake, professor of planetary science and chemistry at Caltech. "In the early solar system, comets and asteroids must have been moving all over the place, and it appears that some of them crash-landed on our planet and made our oceans."

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes. NASA's Herschel Project Office is based at the agency's Jet Propulsion Laboratory in Pasadena, Calif., which contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at Caltech in Pasadena, supports the U.S. astronomical community. Caltech manages JPL for NASA.

 Householders own multitude of choices for enhancement that may bump up the value of their home even as improving its comfort.           

Are you a home owner and thinking to improve your house completely either by repainting a room or have you thought about projects which could add aesthetic value?

Reduce your house’s heat with the help of radiant barrier as it is easy to use, safe to handle and effectual at plummeting heat loss and it can also turn back the extreme rays of the sun during the summer time and keeping the house cooler too.

Spray foam insulation: It is a general and an essential thing that we insulate our homes to condense speed of heat loss. The insulation is carried by using spray foam in the opening, chink and the crevice such that there is no amend of heat linking the walls of the house and the environment.

 Some of the Benefits of Spray Foam Insulation Include:

Reduction in sound diffusion, better environment, Keep Pests Outdoors, reduction in noise levels, Reduction in moisture and the development of Mold, apart from this it also has certain benefits like generating improved environment by plummeting dust, dirt, and pollen, Saving Energy structuring effectiveness & a Green Environment, produces air tight thermal seal, stops air and dampness penetration, Makes your home more comfortable, trim down capacity requirements, maintenance and wear of HVAC equipment.

 

Attic ventilation keeps the loft cooler in the summer and dry in the winter. Attic ventilation keeps the loft cooler in the summer and dry in the winter. Good exposure to air boosts the act of your insulation, expands the life of your HVAC unit and saves you even more money on energy bills.

Benefits of attic ventilation: it extends the life of your roof, cut downs the load on your HVAC system, stops ice damming in colder regions, and diminishes moisture build-up in the loft.

Source : Know More Details About Radiant Barrier by Visiting

The existence of a world with a double sunset, as portrayed in the film Star Wars more than 30 years ago, is now scientific fact. NASA's Kepler mission has made the first unambiguous detection of a circumbinary planet -- a planet orbiting two stars -- 200 light-years from Earth.

Unlike Star Wars’ Tatooine, the planet is cold, gaseous and not thought to harbor life, but its discovery demonstrates the diversity of planets in our galaxy. Previous research has hinted at the existence of circumbinary planets, but clear confirmation proved elusive. Kepler detected such a planet, known as Kepler-16b, by observing transits, where the brightness of a parent star dims from the planet crossing in front of it.

"This discovery confirms a new class of planetary systems that could harbor life," Kepler principal investigator William Borucki said. "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."

A research team led by Laurance Doyle of the SETI Institute in Mountain View, Calif., used data from the Kepler space telescope, which measures dips in the brightness of more than 150,000 stars, to search for transiting planets. Kepler is the first NASA mission capable of finding Earth-size planets in or near the "habitable zone," the region in a planetary system where liquid water can exist on the surface of the orbiting planet.

Scientists detected the new planet in the Kepler-16 system, a pair of orbiting stars that eclipse each other from our vantage point on Earth. When the smaller star partially blocks the larger star, a primary eclipse occurs, and a secondary eclipse occurs when the smaller star is occulted, or completely blocked, by the larger star.

Astronomers further observed that the brightness of the system dipped even when the stars were not eclipsing one another, hinting at a third body. The additional dimming in brightness events, called the tertiary and quaternary eclipses, reappeared at irregular intervals of time, indicating the stars were in different positions in their orbit each time the third body passed. This showed the third body was circling, not just one, but both stars, in a wide circumbinary orbit.

The gravitational tug on the stars, measured by changes in their eclipse times, was a good indicator of the mass of the third body. Only a very slight gravitational pull was detected, one that only could be caused by a small mass. The findings are described in a new study published Friday, Sept. 16, in the journal Science.

"Most of what we know about the sizes of stars comes from such eclipsing binary systems, and most of what we know about the size of planets comes from transits," said Doyle, who also is the lead author and a Kepler participating scientist. "Kepler-16 combines the best of both worlds, with stellar eclipses and planetary transits in one system."

This discovery confirms that Kepler-16b is an inhospitable, cold world about the size of Saturn and thought to be made up of about half rock and half gas. The parent stars are smaller than our sun. One is 69 percent the mass of the sun and the other only 20 percent. Kepler-16b orbits around both stars every 229 days, similar to Venus’ 225-day orbit, but lies outside the system’s habitable zone, where liquid water could exist on the surface, because the stars are cooler than our sun.

"Working in film, we often are tasked with creating something never before seen," said visual effects supervisor John Knoll of Industrial Light & Magic, a division of Lucasfilm Ltd., in San Francisco. "However, more often than not, scientific discoveries prove to be more spectacular than anything we dare imagine. There is no doubt these discoveries influence and inspire storytellers. Their very existence serves as cause to dream bigger and open our minds to new possibilities beyond what we think we 'know.'"

Expedition 28 Commander Andrey Borisenko and Flight Engineers Alexander Samokutyaev and Ron Garan landed their Soyuz TMA-21 spacecraft in Kazakhstan a few seconds before midnight EDT Friday, with an official landing time of 11:59:39 p.m. Thursday. Russian recovery teams were on hand to help the crew exit the Soyuz vehicle and adjust to gravity after 164 days in space.

The trio launched aboard the Soyuz TMA-21 spacecraft from the Baikonur Cosmodrome in Kazakhstan in April and spent 162 days living and working aboard the International Space Station.

Samokutyaev was at the controls of the spacecraft as it undocked at 8:38 p.m. Thursday from the Poisk docking port on the station's Zvezda service module.

The undocking marked the end of Expedition 28 and the start of Expedition 29 under the command of NASA astronaut Mike Fossum, who is scheduled to remain on the station with Flight Engineers Sergei Volkov and Satoshi Furukawa until November. Borisenko ceremonially handed command of the station over to Fossum on Wednesday. Fossum, Volkov and Furukawa arrived at the station aboard the Soyuz TMA-02M spacecraft in June.

NASA and its international partners have agreed to a tentative launch schedule with crew flights to the International Space Station resuming on Nov. 14. The Space Station Control Board, with representation from all partner agencies, set the schedule after hearing the Russian Federal Space Agency’s findings on the Aug. 24 loss of the Progress 44 cargo craft. The dates may be adjusted to reflect minor changes in vehicle processing timelines.

According to the current plan, the Soyuz 28 spacecraft, carrying NASA's Dan Burbank and Russia's Anatoly Ivanishin and Anton Shkaplerov, will launch Nov. 14 from the Baikonur Cosmodrome in Kazakhstan and arrive at the station on Nov. 16.

The Herschel infrared space observatory has discovered that galaxies do not always need to collide with each other to drive vigorous star birth. The finding overturns a long-held assumption and paints a more stately picture of how galaxies evolve.

Herschel is a European Space Agency mission with important contributions from NASA and NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"Galaxy mergers play an important role in producing the most powerful starbursts today," said Lee Armus, a co-author of the new study from NASA's Herschel Science Center at the California Institute of Technology in Pasadena. "But in the early universe, when most galaxies contained a lot more gas, mergers were not the only way, or even the most common way, to make lots of stars at a rapid rate."

The new results are based on Herschel's observations of two patches of sky, each about one-third the size of the full moon.

It's like looking through a keyhole across the universe. Herschel has seen more than a thousand galaxies at a variety of distances from Earth, spanning 80 percent of the age of the cosmos.

These observations are unique because Herschel can obtain data at a wide range of infrared light and reveal a more complete picture of star birth than ever seen before.

The results appear in the journal Astronomy & Astrophysics. Read more at http://www.esa.int/SPECIALS/Herschel/SEM2Y40UDSG_0.html .

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at Caltech, supports the United States astronomical community. Caltech manages JPL for NASA.

You are in space...your spacecraft is tumbling out of control, you need to fire your control rockets, the fuel is sloshing all around the inside of the tank...where is your liquid fuel? Without gravity in the space environment, how do you keep the fuel contained so it can be transported to where it is needed? How do you keep gas bubbles out of the fuel lines?

Being able to use all of the fuel in a spacecraft tank has been an ongoing challenge in spacecraft design for the past 50 years, but great advances on the problem are being made using the International Space Station as a laboratory. In the microgravity of space, the "bottom" of the tank is NOT apparent.

When a spacecraft tank is nearly full, the fuel tends to "cling" to all sides of the tank leaving a small gas bubble, or ullage, near the center of the tank. Once the tank has emptied to the point where there is not enough liquid to cover the walls of the tank, it is not clear where the remaining fluid is "positioned." Here on Earth this is not an issue. For example, in the gasoline tank in your car, gravity always positions the remaining fluid at the bottom of the tank, allowing the car's fuel pump to draw the last bit of fuel from the tank.

"Presently, the low risk solution to this problem is to size the fuel tank larger than what is needed for the mission, but this adds extra launch mass and volume to the spacecraft," states Robert Green at NASA's Glenn Research Center. Another method is to add special channel-like structures, called vanes, inside the tank to purposely "wick" the remaining fuel to the exit. A key area of study is how different shapes of channels work and whether they remove any gas bubbles that can get captured in the flow.

Scientists from Germany and the U.S. have been studying these processes as part of an investigation called Capillary Channel Flow, or CCF. The CCF study looks at several capillary channel geometries that mimic the shape and physical characteristics of vanes in fuel tanks.

One set of capillary channel geometries was developed by Michael E. Dreyer at the Center of Applied Space Technology and Microgravity, or ZARM, at the University of Bremen in Bremen, Germany, and sponsored by the German Aerospace Center, or DLR. The geometries included parallel plates and square-grooves. This part of the investigation was completed in March 2011, after 78 days of nearly continuous ground-controlled operation.

The second set of channel geometries was designed by Mark M. Weislogel at Portland State University in Portland, Ore. Sponsored by NASA, it will begin operation this month. The geometry is a wedge-shaped channel with only one side exposed to the interior of the tank. Weislogel is studying the fluid behavior in the interior corner where the two plates meet. This area forms a wedge-shaped channel geometry, which forces gas bubbles to rise and burst past the liquid surface. This new shape enables the passive separation of gas from liquid.

Every space system that includes a fluid, from drinking water, to radiators, to toilets, can have problems with transport and bubbles. So using the geometry of the channel to remove bubbles can be a real advantage, as Weislogel explained when discussing the importance of studying the wedge shape. "In a spacecraft tank application, if gas bubbles get to the engine, the engine can sputter or stall. If the fuel lines have these wedge-shaped sections, they can expel the gas en route, and the wedge-shaped section takes care of the separation for you," said Weislogel.

The CCF investigation was installed in the Microgravity Science Glovebox, or MSG, a research facility aboard the space station. The MSG facility is designed to accommodate small science and technology experiments in a workbench type environment. The experiment can be controlled from NASA's Glenn Research Center, from Germany, or at Portland State.

"Technologies utilizing capillary flow can be used in applications on Earth," explained Green. "CCF results may potentially be applied for improving fluid flow in miniaturized biological devices used for health screening and analysis -- referred to as lab-on-a-chip."

Space Farm 7 is a celebration of NASA's space, science and exploration programs that both honors the agency's missions and features a contest, the grand prize winner of which will win four tickets to visit the Kennedy Space Center and dine with an astronaut.

Each of the seven participating farms planted corn mazes that feature designs celebrating NASA's achievements and each of the Space Farms are paired with the closest NASA center in order to highlight that region’s contribution to the agency. The farms are open to the public and feature NASA-related educational games and activities. This outreach project will expose participants to NASA's space exploration and other missions.

Sunspot 1283 erupted with another flare yesterday that peaked at 6:20 PM ET. This was an X2.1 class flare, some four times stronger than the earlier flare. Flares can affect Earth's ionosphere, through which high frequency radio waves travel, and cause radio blackouts. This strength flare can cause a "strong" radio blackout, categorized as R3, which has the potential to cause about an hour-long blackout.

This flare, too, had a coronal mass ejection (CME) – an eruption of a giant cloud of solar material -- associated with it. Early models suggest that both CMEs will not travel directly toward Earth, but perhaps just graze our atmosphere in the North, potentially causing auroras in the northern latitudes.

Further updates on the event will be provided as they become available.

NASA's GRAIL spacecraft are set to launch to the moon aboard a United Launch Alliance Delta II rocket on Sept. 8, 2011, from Cape Canaveral Air Force Station, Fla. There are two instantaneous (one-second) launch windows at 5:37:06 a.m. and 6:16:12 a.m. PDT (8:37:06 a.m. and 9:16:12 a.m. EDT). The launch period extends through Oct. 19. The launch times occur approximately four minutes earlier each day.

GRAIL's primary science objectives are to determine the structure of the lunar interior, from crust to core, and to advance understanding of the thermal evolution of the moon.

The lunar orbiters are nestled inside the top of a United Launch Alliance Delta II 7920H-10C rocket, the most powerful Delta rocket in NASA's inventory.

On launch day, Sept. 8, NASA TV commentary coverage of the countdown will begin at 3 a.m. PDT (6 a.m. EDT). The coverage will be webcast at http://www.nasa.gov/ntv .

Live countdown coverage on NASA's launch blog also begins at 3 a.m. PDT (6 a.m. EDT) at http://www.nasa.gov/mission_pages/grail/launch/grail_blog.html . Coverage features real-time updates of countdown milestones, as well as streaming video clips highlighting launch preparations and liftoff. To access these features, and for more information on GRAIL, visit http://www.nasa.gov/grail and http://grail.nasa.gov .

The launch will also be online, with a live chat available, on Ustream TV, at http://www.ustream.tv/nasajpl2 . To follow the GRAIL launch on Twitter, visit http://twitter.com/NASAJPL and http://twitter.com/NASA .

Here is a timeline of expected launch milestones:

Launch

At liftoff, the rocket's first-stage engine and six of its nine strap-on solid rocket motors will ignite, and the rocket will be airborne, carrying GRAIL up and over the Atlantic Ocean.

First six solid rocket motors are jettisoned

GRAIL's Delta II is carrying nine strap-on graphite-epoxy motors. The first six will be ignited at the time of liftoff. The remaining three will be ignited shortly after the first six strap-on motors burn out.

Fairing separates

After the Delta's first stage completes its tour of duty, its second stage, which will provide 9,645 pounds of kick for GRAIL, will begin the first of two scheduled burns.

Shortly after ignition of the rocket's second stage, the Delta's 30-foot-long (8.88-meter-long) nose cone, or fairing, will separate and be jettisoned as planned, providing the GRAIL twins with their first taste of exo-atmospheric existence.

Parking at 17,500 miles per hour

The Delta's second stage will temporarily stop firing, as planned, and the rocket and GRAIL will begin a planned coast phase, also known as a "parking orbit" at about 90 miles (nearly 167 kilometers up).

GRAIL heading from Earth to the moon

The Delta's second stage will begin a second burn. This approximately four-and-a-half-minute-long burn will place GRAIL on its desired trajectory to the moon.

Spacecraft begin to separate from second stage

The GRAIL-A spacecraft begins its separation process from the Delta's second stage. The GRAIL-B spacecraft separates about 8 minutes later. At this point, the moon is three-and-a-half months away.

At 9:35 PM ET on September 5, 2011, the sun emitted an Earth-directed M5.3 class flare as measured by the GOES satellite. The flare erupted from a region of the sun that appears close to dead center from Earth's perspective, an active region designated number 1283. The flare caused a slight increase of solar energetic protons some 26,000 miles above Earth's surface.

A coronal mass ejection (CME) -- another solar phenomenon that can send solar particles into space -- was associated with this flare. The CME is a relatively slow one, traveling at under 200 miles per second.

Further updates on the event will be provided as they become available.

NASA will host a media teleconference on Thursday, Sept. 1, at 12:30 p.m. PDT (3:30 p.m. EDT) to discuss progress of NASA's Mars Exploration Rover Opportunity. Opportunity reached the Martian Endeavour crater earlier this month after years of driving.

The teleconference participants are:

-- Dave Lavery, program executive, Mars Exploration Rovers, NASA Headquarters, Washington

-- Steve Squyres, principal investigator, Mars Exploration Rovers, Cornell University, Ithaca, N.Y.

-- Ray Arvidson, deputy principal investigator, Mars Exploration Rovers, Washington University in St. Louis.

-- John Callas, project manager, Mars Exploration Rovers, Jet Propulsion Laboratory, Pasadena, Calif.

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. They continued to work for years in bonus mission extensions. Spirit finished communicating in 2010, after six years of operation.

Opportunity, still very active, reached the rim of Endeavour crater on Aug. 9. The arrival gives the rover access to geology different from any it explored during its first 90 months on Mars.

NASA has invited 150 followers of the agency's Twitter accounts to a two-day launch Tweetup Sept. 7-8. The Tweetup is expected to culminate in the launch of the twin moon-bound GRAIL spacecraft aboard a Delta II rocket from Cape Canaveral Air Force Station in Florida.

The launch is targeted for 5:37 a.m. PDT (8:37 a.m. EDT) on Sept. 8. The two GRAIL spacecraft will fly in tandem orbits around the moon for several months to measure its gravity field in unprecedented detail from crust to core. The mission also will answer longstanding questions about the moon and provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed.

Tweetup participants were selected from more than 800 people who registered online. They will share their Tweetup experiences with their followers through the social networking site Twitter.

Participants represent the United States, Australia, Brazil, Canada, India, Indonesia, Spain and the United Kingdom. Attendees from the U.S. come from 32 states: Alabama, Arizona, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Illinois, Indiana, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New York, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Utah, Virginia, Washington and Wisconsin.

Beginning at noon PDT (3 p.m. EDT) on Wednesday, Sept. 7, NASA will broadcast a portion of the Tweetup when attendees talk with NASA Administrator Charles Bolden; Jim Adams, deputy director of planetary science at NASA Headquarters in Washington; Maria Zuber, GRAIL principal investigator at the Massachusetts Institute of Technology in Cambridge; Sami Asmar, GRAIL deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.; and Neil deGrasse Tyson, astrophysicist and Frederick P. Rose Director at the American Museum of Natural History's Hayden Planetarium in New York. To watch the broadcast, visit: http://www.ustream.tv/channel/nasa-tweetup . The event will also be streamed live, with a moderated chat, at http://www.ustream.tv/nasajpl2 .

Participants also will tour NASA's Kennedy Space Center and Cape Canaveral, including a close-up visit to the launch pad.

Reporters interested in interviewing Tweetup attendees should contact Stephanie Schierholz at 202-358-1100 or stephanie.schierholz@nasa.gov. Reporters interested in covering the afternoon program Sept. 7 at the Kennedy Space Center Visitor Complex must secure access through Andrea Farmer by 2 p.m. PDT (5 p.m. EDT) Sept. 6 at 321-449-4318 or afarmer@dncinc.com.

Previously, NASA invited groups to attend the launch of the Juno spacecraft on its way to Jupiter and five space shuttle launches: Atlantis' STS-129, STS-132 and STS-135 missions, Discovery's STS-133 mission and Endeavour's STS-134 mission.

To follow participants on Twitter as they experience the prelaunch events and GRAIL's liftoff, follow the #NASATweetup hashtag and the list of attendees at: http://twitter.com/nasatweetup/grail-launch.

Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way. Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon.

The black holes are located near the center of the spiral galaxy NGC 3393. Separated by only 490 light years, the black holes are likely the remnant of a merger of two galaxies of unequal mass a billion or more years ago.

"If this galaxy wasn't so close, we'd have no chance of separating the two black holes the way we have," said Pepi Fabbiano of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., who led the study that appears in this week's online issue of the journal Nature. "Since this galaxy was right under our noses by cosmic standards, it makes us wonder how many of these black hole pairs we've been missing."

Previous observations in X-rays and at other wavelengths indicated that a single supermassive black hole existed in the center of NGC 3393. However, a long look by Chandra allowed the researchers to detect and separate the dual black holes. Both black holes are actively growing and emitting X-rays as gas falls towards them and becomes hotter.

When two equal-sized spiral galaxies merge, astronomers think it should result in the formation of a black hole pair and a galaxy with a disrupted appearance and intense star formation. A well-known example is the pair of supermassive black holes in NGC 6240, which is located about 330 million light years from Earth.

However, NGC 3393 is a well-organized spiral galaxy, and its central bulge is dominated by old stars. These are unusual properties for a galaxy containing a pair of black holes. Instead, NGC 3393 may be the first known instance where the merger of a large galaxy and a much smaller one, dubbed a "minor merger" by scientists, has resulted in the formation of a pair of supermassive black holes. In fact, some theories say that minor mergers should be the most common way for black hole pairs to form, but good candidates have been difficult to find because the merged galaxy is expected to look so typical.

"The two galaxies have merged without a trace of the earlier collision, apart from the two black holes," said co-author Junfeng Wang, also from CfA. "If there was a mismatch in size between the two galaxies it wouldn't be a surprise for the bigger one to survive unscathed."

If this was a minor merger, the black hole in the smaller galaxy should have had a smaller mass than the other black hole before their host galaxies started to collide. Good estimates of the masses of both black holes are not yet available to test this idea, although the observations do show that both black holes are more massive than about a million suns. Assuming a minor merger occurred, the black holes should eventually merge after about a billion years.

Both of the supermassive black holes are heavily obscured by dust and gas, which makes them difficult to observe in optical light. Because X-rays are more energetic, they can penetrate this obscuring material. Chandra's X-ray spectra show clear signatures of a pair of supermassive black holes.

The NGC 3393 discovery has some similarities to a possible pair of supermassive black holes found recently by Julia Comerford of the University of Texas at Austin, also using Chandra data. Two X-ray sources, which may be due to supermassive black holes in a galaxy about two billion light years from Earth, are separated by about 6,500 light years. As in NGC 3393, the host galaxy shows no signs of disturbance or extreme amounts of star formation. However, no structure of any sort, including spiral features, is seen in the galaxy. Also, one of the sources could be explained by a jet, implying only one supermassive black hole is located in the galaxy.

"Collisions and mergers are one of the most important ways for galaxies and black holes to grow," said co-author Guido Risaliti of CfA and the National Institute for Astrophysics in Florence, Italy. "Finding a black hole pair in a spiral galaxy is an important clue in our quest to learn how this happens."

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

NASA's Gravity Recovery And Interior Laboratory (GRAIL) mission to study the moon is in final launch preparations for a scheduled Sept. 8 launch from Cape Canaveral Air Force Station in Florida.

GRAIL's twin spacecraft are tasked for a nine-month mission to explore Earth's nearest neighbor in unprecedented detail. They will determine the structure of the lunar interior from crust to core and advance our understanding of the thermal evolution of the moon.

"Yesterday's final encapsulation of the spacecraft is an important mission milestone," said David Lehman, GRAIL project manager for NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our two spacecraft are now sitting comfortably inside the payload fairing which will protect them during ascent. Next time the GRAIL twins will see the light of day, they will be about 95 miles up and accelerating."

The spacecraft twins, GRAIL-A and GRAIL-B, will fly aboard a Delta II rocket launched from Florida. The twins' circuitous route to lunar orbit will take 3.5 months and cover approximately 2.6 million miles (4.2 million kilometers) for GRAIL-A, and 2.7 million miles (4.3 million kilometers) for GRAIL-B.

In lunar orbit, the spacecraft will transmit radio signals precisely defining the distance between them. Regional gravitational differences on the moon are expected to expand and contract that distance.

GRAIL scientists will use these accurate measurements to define the moon's gravity field. The data will allow mission scientists to understand what goes on below the surface of our natural satellite.

"GRAIL will unlock lunar mysteries and help us understand how the moon, Earth and other rocky planets evolved as well," said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge.

GRAIL's launch period opens Sept. 8 and extends through Oct. 19. On each day, there are two separate launch opportunities separated by approximately 39 minutes. On Sept. 8, the first launch opportunity is 8:37 a.m. EDT (5:37 a.m. PDT); the second is 9:16 a.m. EDT (6:16 a.m. PDT).

Picture preparing a bowl full of a sweet, gelatin dessert. The gelatin powder is mixed with hot water, and then the mixture is cooled in a refrigerator until it sets. It is now a gel. If that wiggly gel were placed in an oven and all of the moisture dried out of it, all that would be left would be a pile of powder.

But imagine if the dried gelatin maintained its shape, even after the liquid had been removed. The structure of the gel would remain, but it would be extremely light due to low density. This is precisely how aerogels are made.

Aerogels are among the lightest solid materials known to man. They are created by combining a polymer with a solvent to form a gel, and then removing the liquid from the gel and replacing it with air. Aerogels are extremely porous and very low in density. They are solid to the touch. This translucent material is considered one of the finest insulation materials available.

Although aerogels were first invented in the 1930s, NASA's Glenn Research Center in Cleveland has invented groundbreaking methods of creating new types of aerogels that could change the way we think about insulation.

Aerogels' Porous Materials

Since their invention, aerogels have primarily been made of silica. The silica is combined with a solvent to create a gel. This gel is then subjected to supercritical fluid extraction. This supercritical fluid extraction involves introducing liquid carbon dioxide into the gel. The carbon dioxide surpasses its super critical point, where it can be either a gas or a liquid, and then is vented out. This exchange is performed multiple times to ensure that all liquids are removed from the gel. The resulting material is aerogel.

"That is the key step that makes an aerogel different from other porous materials," says Mary Ann Meador, a research chemical engineer and team lead for aerogels at Glenn. "Maintaining the gel structure is the most important thing."

Aerogels provide very effective insulation, because they are extremely porous and the pores are in the nanometer range. The nano pores aren't visible to the human eye. The existence of these pores makes the aerogel so adept at insulating.

"The pores are so small, and gas phase heat conduction is very poor," Meador says. "Molecules of air cannot travel through the aerogel, so there is poor heat transfer through the material."

Traditional silica-based aerogels have been successfully used in many applications, such as providing insulation on a Mars Rover. They have also been used in many commercial products. When aerogels are used for commercial purposes, they are typically in pellet form or in a composite with other materials. Aerogels have been combined with batting to create insulating "blankets," as well as filled in between panes of glass to create translucent panels for day-lighting applications.

Silica-based aerogels are very light, as they are about 95% porous. Silica aerogels are very useful, but they have limitations—they are very fragile.

Aerogel Innovations

NASA, along with industry partners, has investigated the use of different types of aerogels for multiple uses. With funding from NASA's Fundamental Aeronautics Program (Hypersonics and Subsonic Fixed Wing Projects) and the Exploration Systems Mission Directorate, NASA's Glenn Research Center has developed two cutting-edge methodologies that revolutionize aerogel technology.

The first innovation is a method of creating aerogels that are reinforced by polymers. The method changes the surface of the gel as it reacts with a polymer. The result is that the interior surface of the aerogel gets a thin layer of polymer, which greatly strengthens the aerogel.

"If you were to compare a polymer-enforced silica aerogel with the same density silica gel, the polymer enforced aerogel is about two orders of magnitude stronger," Meador says.

These polymer-enhanced aerogels offer the same insulation properties as typical aerogels and can be translucent. They share the same positive attributes of silica aerogels, and are much less fragile. The Glenn team has created many different aerogels featuring different polymers using their patented method. Glenn has also collaborated with Aspen Aerogel of Northborough, Mass. to create a polymer-enhanced aerogel that was combined with fibers to create a new product.

The second innovation is a method of creating aerogels made completely of polymers. These polymer-based aerogels are extremely strong and flexible. They can also be made into a bendable thin film.

Aerogels in Flight

The Glenn team is currently working on a NASA project called the Hypersonic Inflatable Aerodynamic Decelerator (HIAD). The HIAD is an inflatable reentry vehicle that is folded and stowed inside a launch vehicle. Prior to entering the atmosphere, the HIAD is inflated and becomes rigid. This helps the spacecraft slow down, safely descend and land on Earth, Mars, or any other planet that has an atmosphere.

The HIAD enables larger masses to be carried through the atmosphere more slowly and safely, and it reduces the heat to which the vehicle is subjected. The HIAD is covered by a Flexible Thermal Protection System, which uses aerogels as an insulator to protect the payload.

The thin film polymer-based aerogel is well suited to the needs of the HIAD. The HIAD (funded by the Hypersonics Project of the Fundamental Aeronautics Program) is scheduled to flight test in 2012. An important component will be the Flexible Thermal Protection Systems (funded by the Hypersonics Project and the Space Technology Program under the NASA Chief Technologist). The Flexible Thermal Protection Systems use baseline aerogel insulation blankets, created by Aspen Aerogels. Subsequent test launches may include the new thin film polymer-based aerogel as an improvement over the baseline insulation.

"The project would like an aerogel that is more flexible, more foldable and doesn't dust, doesn't shed insulation particles, so it is not a hazard or messy to handle. In response to that, we started looking at different kinds of polymers and techniques that could make that sort of aerogel more flexible," Meador says.

The team determined that the presence of silica in an aerogel precluded the ability of an aerogel to be flexible, so they started exploring ways to create an aerogel made completely with polymers. They developed a method of creating polymer based aerogels that are completely flexible, and can be made into an extremely thin film—a capability not previous available. These aerogels are also stable even when subjected to high temperatures.

The polymer-based aerogel is 85-95% porous, meaning it offers the same advantages of traditional aerogels. It is equally light in weight, and has the same properties of thermal conductivity as silica based aerogels. But these aerogels offer unprecedented flexibility, along with their durability and strength, and the ability to be made into a thin film.

"I was amazed and surprised when we determined it could be made into a flexible thin film," Meador says. "It was a 'whoa' moment! It was better than we expected."

Aerogel Applications

The thin films, which are fabricated through a collaboration with the University of Akron in Akron, Ohio, have also been sent to other government agencies and NASA centers, which has garnered interest in the technology.

"Usually when people see them, they say 'Wow, this is an aerogel?'" Meador says.

Other NASA centers have expressed interest in further exploring these thin polymer aerogels, for applications like cryogenics or in the next space suit. Polymer aerogels are ideally suited for use in a vacuum, like in space, as well as in different gravity scenarios, such as the moon or other planets.

Governmental agencies are also interested in exploring the thin polymer aerogels for use in shelter applications, such as insulated tents. Industry has also taken notice, with possible applications in refrigeration, building and construction, updating historical structures, and many other insulation needs, especially when there isn't a lot of room and smaller, more effective insulation is needed.

Aerogels and the Future

Polymer-enhanced aerogels and polymer-based aerogels have numerous potential applications, both in space, on distant planets and on our own Earth. They are light, durable and extremely effective at insulating and preventing heat transfer. NASA has taken aerogels to the next level, beyond what was previously imagined, and uncovered a world of possibilities for this versatile material.

Imagine forecasting a hurricane in Miami weeks before the storm was even a swirl of clouds off the coast of Africa—or predicting a tornado in Kansas from the flutter of a butterfly's wing in Texas. These are the kind of forecasts meteorologists can only dream about.

Could the dream come true? A new study by Stanford researchers suggests that such forecasts may one day be possible—not on Earth, but on the sun.

"We have learned to detect sunspots before they are visible to the human eye," says Stathis Ilonidis, a PhD student at Stanford University. "This could lead to significant advances in space weather forecasting."

Sunspots are the "butterfly's wings" of solar storms. Visible to the human eye as dark blemishes on the solar disk, sunspots are the starting points of explosive flares and coronal mass ejections (CMEs) that sometimes hit our planet 93 million miles away. Consequences range from Northern Lights to radio blackouts to power outages.

Astronomers have been studying sunspots for more than 400 years, and they have pieced together their basic characteristics: Sunspots are planet-sized islands of magnetism that float in solar plasma. Although the details are still debated, researchers generally agree that sunspots are born deep inside the sun via the action of the sun’s inner magnetic dynamo. From there they bob to the top, carried upward by magnetic buoyancy; a sunspot emerging at the stellar surface is a bit like a submarine emerging from the ocean depths.

In the August 19th issue of Science, Ilonidis and co-workers Junwei Zhao and Alexander Kosovichev announced that they can see some sunspots while they are still submerged.

Their analysis technique is called "time-distance helioseismology," and it is similar to an approach widely used in earthquake studies. Just as seismic waves traveling through the body of Earth reveal what is inside the planet, acoustic waves traveling through the body of the sun can reveal what is inside the star. Fortunately for helioseismologists, the sun has acoustic waves in abundance. The body of the sun is literally roaring with turbulent boiling motions. This sets the stage for early detection of sunspots.

"We can't actually hear these sounds across the gulf of space," explains Ilonidis, "but we can see the vibrations they make on the sun's surface." Instruments onboard two spacecraft, the venerable Solar and Heliospheric Observatory (SOHO) and the newer Solar Dynamics Observatory (SDO) constantly monitor the sun for acoustic activity.

Submerged sunspots have a detectable effect on the sun's inner acoustics—namely, sound waves travel faster through a sunspot than through the surrounding plasma. A big sunspot can leapfrog an acoustic wave by 12 to 16 seconds. "By measuring these time differences, we can find the hidden sunspot."

Ilonidis says the technique seems to be most sensitive to sunspots located about 60,000 km beneath the sun’s surface. The team isn't sure why that is "the magic distance," but it's a good distance because it gives them as much as two days advance notice that a spot is about to reach the surface.

"This is the first time anyone has been able to point to a blank patch of sun and say 'a sunspot is about to appear right there,'" says Ilonidis's thesis advisor Prof. Phil Scherrer of the Stanford Physics Department. "It's a big advance."

"There are limits to the technique," cautions Ilonidis. "We can say that a big sunspot is coming, but we cannot yet predict if a particular sunspot will produce an Earth-directed flare."

So far they have detected five emerging sunspots—four with SOHO and one with SDO. Of those five, two went on to produce X-class flares, the most powerful kind of solar explosion. This encourages the team to believe their technique can make a positive contribution to space weather forecasting. Because helioseismology is computationally intensive, regular monitoring of the whole sun is not yet possible—"we don’t have enough CPU cycles," says Ilonidis —but he believes it is just a matter of time before refinements in their algorithm allow routine detection of hidden sunspots.

If this were an inkblot test, you might see a bow tie or a butterfly depending on your personality. An astronomer would likely see the remains of a dying star scattered about space -- precisely what this is. NASA's Spitzer Space Telescope captured this infrared view of what's called a planetary nebula, which is a cloud of material expelled by a burnt out star, called a white dwarf. This object is named the Dumbbell nebula after its resemblance to the exercise equipment in visible-light views.

"It is interesting how different Spitzer's view of the Dumbbell looks compared to optical images," said Dr. Joseph Hora, the principal investigator of the observations from the Harvard Smithsonian Center for Astrophysics, Cambridge, Mass.

In Spitzer's infrared view, the diffuse green glow, which is brightest near the center, is probably from hot gas atoms being heated by the ultraviolet light from the central white dwarf. A collection of clumps fill the central part of the nebula, and red-colored radial spokes extend well beyond. Astronomers think these features represent molecules of hydrogen gas, mixed with traces of heavier elements. Despite being broken apart by the ultraviolet light from the central white dwarf, much of this molecular material may survive intact and mix back into interstellar gas clouds, helping to fuel the next generation of stars.