Smoking Gun Of Black Hole Activation

Data from an ongoing survey by NASA's Swift satellite have helped astronomers solve a decades-long mystery about why a small percentage of black holes emit vast amounts of energy.

Only about one percent of supermassive black holes exhibit this behavior. The new findings confirm that black holes "light up" when galaxies collide, and the data may offer insight into the future behavior of the black hole in our own Milky Way galaxy. The study will appear in the June 20 issue of The Astrophysical Journal Letters.

The intense emission from galaxy centers, or nuclei, arises near a supermassive black hole containing between a million and a billion times the sun's mass. Giving off as much as 10 billion times the sun's energy, some of these active galactic nuclei (AGN) are the most luminous objects in the universe. They include quasars and blazars.

"Theorists have shown that the violence in galaxy mergers can feed a galaxy's central black hole," said Michael Koss, the study's lead author and a graduate student at the University of Maryland in College Park. "The study elegantly explains how the black holes switched on."

Until Swift's hard X-ray survey, astronomers never could be sure they had counted the majority of the AGN. Thick clouds of dust and gas surround the black hole in an active galaxy, which can block ultraviolet, optical and low-energy, or soft X-ray, light. Infrared radiation from warm dust near the black hole can pass through the material, but it can be confused with emissions from the galaxy's star-forming regions. Hard X-rays can help scientists directly detect the energetic black hole.

Safe Homecoming for Atlantis

Space shuttle Atlantis' main gear touched down on Runway 33 at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida at 8:48 a.m. EDT, completing a 12-day mission to the International Space Station. On board were Commander Ken Ham, pilot Tony Antonelli, Garrett Reisman, Michael Good, Steve Bowen and Piers Sellers. The six-member STS-132 crew carried the Russian-built Mini Research Module-1 to the International Space Station. STS-132 is the last planned flight for Atlantis.

Astronauts Michael Good and Garrett Reisman during the spacewalk

Astronauts Michael Good (left) and Garrett Reisman look through the aft flight deck windows of space shuttle Atlantis during the mission’s third aspacewalk. During the spacewalk, Good and Reisman completed the installation of the final two of the six new batteries for the B side of the port 6 solar array. In addition, the astronauts installed a backup ammonia jumper cable between the port 4 and 5 trusses of the station and transferred a power and data grapple fixture from the shuttle to the station.

Atlantis Crew Preparing for Wednesday Landing

Today the space shuttle crew prepares for its return to Earth. Landing opportunities for Atlantis’ planned final mission start on Wednesday.

Commander Ken Ham, Pilot Tony Antonelli and Mission Specialist Mike Good will perform a test of the flight control system and a “hot fire” of the reaction control system in preparation for landing opportunities.

Mission Specialists Garrett Reisman, Steve Bowen and Piers Sellers will work on final packing and stowage activities in the morning and be joined by their crewmates to continue that work throughout the day. Each of the crew members also has exercise planned and they will all participate in a briefing to review the deorbit plans.

The entire Atlantis crew will gather in the shuttle flight deck to talk with representatives from the Colbert Report, ABC Radio Network and WEWS-TV of Cleveland. That event will air on NASA TV at 8:10 a.m. EDT.

NASA's Hubble Space Telescope Finds a Star Eating a Planet

The hottest known planet in the Milky Way galaxy may also be its shortest-lived world. The doomed planet is being eaten by its parent star, according to observations made by a new instrument on NASA's Hubble Space Telescope, the Cosmic Origins Spectrograph (COS). The planet may only have another 10 million years left before it is completely devoured.

The planet, called WASP-12b, is so close to its sunlike star that it is superheated to nearly 2,800 degrees Fahrenheit and stretched into a football shape by enormous tidal forces. The atmosphere has ballooned to nearly three times Jupiter's radius and is spilling material onto the star. The planet is 40 percent more massive than Jupiter.

This effect of matter exchange between two stellar objects is commonly seen in close binary star systems, but this is the first time it has been seen so clearly for a planet.

"We see a huge cloud of material around the planet, which is escaping and will be captured by the star. We have identified chemical elements never before seen on planets outside our own solar system," says team leader Carole Haswell of The Open University in Great Britain.

Haswell and her science team's results were published in the May 10, 2010 issue of The Astrophysical Journal Letters.

A theoretical paper published in the science journal Nature last February by Shu-lin Li of the Department of Astronomy at the Peking University, Beijing, first predicted that the planet's surface would be distorted by the star's gravity, and that gravitational tidal forces make the interior so hot that it greatly expands the planet's outer atmosphere. Now Hubble has confirmed this prediction.

WASP-12 is a yellow dwarf star located approximately 600 light-years away in the winter constellation Auriga. The exoplanet was discovered by the United Kingdom's Wide Area Search for Planets (WASP) in 2008. The automated survey looks for the periodic dimming of stars from planets passing in front of them, an effect called transiting. The hot planet is so close to the star it completes an orbit in 1.1 days.

The unprecedented ultraviolet (UV) sensitivity of COS enabled measurements of the dimming of the parent star's light as the planet passed in front of the star. These UV spectral observations showed that absorption lines from aluminum, tin, manganese, among other elements, became more pronounced as the planet transited the star, meaning that these elements exist in the planet's atmosphere as well as the star's. The fact the COS could detect these features on a planet offers strong evidence that the planet's atmosphere is greatly extended because it is so hot.

The UV spectroscopy was also used to calculate a light curve to precisely show just how much of the star's light is blocked out during transit. The depth of the light curve allowed the COS team to accurately calculate the planet's radius. They found that the UV-absorbing exosphere is much more extended than that of a normal planet that is 1.4 times Jupiter's mass. It is so extended that the planet's radius exceeds its Roche lobe, the gravitational boundary beyond which material would be lost forever from the planet's atmosphere.

Garrett Reisman's 25-minute spacewalk

Anchored to the Canadarm2 mobile foot restraint, Garrett Reisman performed construction and maintenance activities outside the station during the STS-132 mission's first spacewalk. During the seven-hour, 25-minute spacewalk, Reisman and NASA astronaut Steve Bowen installed a second antenna for high-speed Ku-band transmissions and added a spare parts platform to Dextre, a two-armed extension for the station’s robotic arm.

NASA : Beauty of Future Airplanes

An 18-month NASA research effort to visualize the passenger airplanes of the future has produced some ideas that at first glance may appear to be old fashioned. Instead of exotic new designs seemingly borrowed from science fiction, familiar shapes dominate the pages of advanced concept studies which four industry teams completed for NASA's Fundamental Aeronautics Program in April 2010.

Look more closely at these concepts for airplanes that may enter service 20 to 25 years from now and you'll see things that are quite different from the aircraft of today.

Just beneath the skin of these concepts lie breakthrough airframe and propulsion technologies designed to help the commercial aircraft of tomorrow fly significantly quieter, cleaner, and more fuel-efficiently, with more passenger comfort, and to more of America's airports.

You may see ultramodern shape memory alloys, ceramic or fiber composites, carbon nanotube or fiber optic cabling, self-healing skin, hybrid electric engines, folding wings, double fuselages and virtual reality windows.

"Standing next to the airplane, you may not be able to tell the difference, but the improvements will be revolutionary," said Richard Wahls, project scientist for the Fundamental Aeronautics Program's Subsonic Fixed Wing Project at NASA's Langley Research Center in Hampton, Va. "Technological beauty is more than skin deep."

In October 2008, NASA asked industry and academia to imagine what the future might bring and develop advanced concepts for aircraft that can satisfy anticipated commercial air transportation needs while meeting specific energy efficiency, environmental and operational goals in 2030 and beyond. The studies were intended to identify key technology development needs to enable the envisioned advanced airframes and propulsion systems.

NASA's goals for a 2030-era aircraft, compared with an aircraft entering service today, are:

* A 71-decibel reduction below current Federal Aviation Administration noise standards, which aim to contain objectionable noise within airport boundaries.
* A greater than 75 percent reduction on the International Civil Aviation Organization's Committee on Aviation Environmental Protection Sixth Meeting, or CAEP/6, standard for nitrogen oxide emissions, which aims to improve air quality around airports.
* A greater than 70 percent reduction in fuel burn performance, which could reduce greenhouse gas emissions and the cost of air travel.
* The ability to exploit metroplex concepts that enable optimal use of runways at multiple airports within metropolitan areas, as a means of reducing air traffic congestion and delays.

The teams were led by General Electric, Massachusetts Institute of Technology, Northrop Grumman and The Boeing Company. Here are some highlights from their final reports:

* The GE Aviation team conceptualizes a 20-passenger aircraft that could reduce congestion at major metropolitan hubs by using community airports for point-to-point travel. The aircraft has an oval-shaped fuselage that seats four across in full-sized seats. Other features include an aircraft shape that smoothes the flow of air over all surfaces, and electricity-generating fuel cells to power advanced electrical systems. The aircraft's advanced turboprop engines sport low-noise propellers and further mitigate noise by providing thrust sufficient for short takeoffs and quick climbs.
* With its 180-passenger D8 "double bubble" configuration, the Massachusetts Institute of Technology team strays farthest from the familiar, fusing two aircraft bodies together lengthwise and mounting three turbofan jet engines on the tail. Important components of the MIT concept are the use of composite materials for lower weight and turbofan engines with an ultra high bypass ratio (meaning air flow through the core of the engine is even smaller, while air flow through the duct surrounding the core is substantially larger, than in a conventional engine) for more efficient thrust. In a reversal of current design trends the MIT concept increases the bypass ratio by minimizing expansion of the overall diameter of the engine and shrinking the diameter of the jet exhaust instead. The team said it designed the D8 to do the same work as a Boeing 737-800. The D8's unusual shape gives it a roomier coach cabin than the 737.
* The Northrop Grumman team foresees the greatest need for a smaller 120-passenger aircraft that is tailored for shorter runways in order to help expand capacity and reduce delays. The team describes its Silent Efficient Low Emissions Commercial Transport, or SELECT, concept as "revolutionary in its performance, if not in its appearance." Ceramic composites, nanotechnology and shape memory alloys figure prominently in the airframe and ultra high bypass ratio propulsion system construction. The aircraft delivers on environmental and operational goals in large part by using smaller airports, with runways as short as 5,000 feet, for a wider geographic distribution of air traffic.
* The Boeing Company's Subsonic Ultra Green Aircraft Research, or SUGAR, team examined five concepts. The team's preferred concept, the SUGAR Volt, is a twin-engine aircraft with hybrid propulsion technology, a tube-shaped body and a truss-braced wing mounted to the top. Compared to the typical wing used today, the SUGAR Volt wing is longer from tip to tip, shorter from leading edge to trailing edge, and has less sweep. It also may include hinges to fold the wings while parked close together at airport gates. Projected advances in battery technology enable a unique, hybrid turbo-electric propulsion system. The aircraft's engines could use both fuel to burn in the engine's core, and electricity to turn the turbofan when the core is powered down.

NASA did not specify future commercial air transportation needs as domestic or global. All four teams focused on aircraft sized for travel within a single continent because their business cases showed that small- and medium-sized planes will continue to account for the largest percentage of the overall fleet in the future. One team, however, did present a large hybrid wing concept for intercontinental transport.

All of the teams provided "clear paths" for future technology research and development, said Ruben Del Rosario, principal investigator for the Subsonic Fixed Wing Project at NASA's Glenn Research Center in Cleveland. "Their reports will make a difference in planning our research portfolio. We will identify the common themes in these studies and use them to build a more effective strategy for the future," Del Rosario said.

These are some of the common themes from the four reports:

* Slower cruising -- at about Mach 0.7, or seven-tenths the speed of sound, which is 5 percent to 10 percent slower than today's aircraft -- and at higher altitudes, to save fuel.
* Engines that require less power on takeoff, for quieter flight.
* Shorter runways -- about 5,000 feet long, on average -- to increase operating capacity and efficiency.
* Smaller aircraft – in the medium-size class of a Boeing 737, with cabin accommodations for no more than 180 passengers – flying shorter and more direct routes, for cost-efficiency.
* Reliance on promised advancements in air traffic management such as the use of automated decision-making tools for merging and spacing enroute and during departure climbs and arrival descents.

The teams recommended a variety of improvements in lightweight composite structures, heat- and stress-tolerant engine materials, and aerodynamic modeling that can help bring their ideas to reality. NASA is weighing the recommendations against its objective of developing aeronautics technologies that can be applied to a broad range of aircraft and operating scenarios for the greatest public benefit.

"This input from our customers has provided us with well thought-out scenarios for our vision of the future, and it will help us place our research investment decisions squarely in the mainstream," said Jaiwon Shin, associate administrator for aeronautics research at NASA Headquarters in Washington.

"Identifying those necessary technologies will help us establish a research roadmap to follow in bringing these innovations to life during the coming years," Shin said.

The next step in NASA's effort to design the aircraft of 2030 is a second phase of studies to begin developing the new technologies that will be necessary to meet the national goals related to an improved air transportation system with increased energy efficiency and reduced environmental impact. The agency received proposals from the four teams in late April and expects to award one or two research contracts for work starting in 2011.

NASA managers also will reassess the goals for 2030 aircraft to determine whether some of the crucial technologies will need additional time to move from laboratory and field testing into operational use. The four teams managed to meet either the fuel burn or the noise goal with their concepts, not both.

A companion research effort looked at concepts for a new generation of supersonic transport aircraft capable of meeting NASA's noise, emissions and fuel efficiency goals for 2030. NASA envisions a broader market for supersonic travel, with aircraft carrying more passengers to improve economic viability while meeting increasingly stringent environmental requirements.

Teams lead by The Boeing Company and Lockheed Martin evaluated market conditions, design goals and constraints, conventional and unconventional configurations, and enabling technologies to create proposed roadmaps for research and development activities. Both teams produced concepts for aircraft that can carry more than 100 passengers at cruise speeds of more than 1.6 Mach and a range of up to 5,000 miles.

Space shuttle Atlantis Lifts Off

Space shuttle Atlantis lifted off from Launch Pad 39A at NASA's Kennedy Space Center in Florida on the STS-132 mission to the International Space Station at 2:20 p.m. EDT on May 14. The third of five shuttle missions planned for 2010, this was the last planned launch for Atlantis. The Russian-built Mini Research Module-1, also known as Rassvet, or "dawn," will be delivered and it will provide additional storage space and a new docking port for Russian Soyuz and Progress spacecraft. The laboratory will be attached to the bottom port of the station's Zarya module. The mission's three spacewalks will focus on storing spare components outside the station, including six batteries, a communications antenna and parts for the Canadian Dextre robotic arm.

Secrets behind Naked Mole-Rats

It was the scientist equivalent of love at first sight.

"They had huge teeth, they ran backwards as much as forwards, and they chatted among themselves constantly," Thomas Park said of the first time he saw a mole-rat during a post-doctoral year in Munich.

After starting his own lab in Chicago, he took his students on a field trip to the zoo and saw the critters again. "I thought they were great, and I knew right then and there that I had to get some of these guys into the lab," he said.

Park, professor of biological sciences at the University of Illinois (UI) at Chicago, began his scientific career studying how birds localized sounds, then switched to bats, examining the effects of sounds on their brain cells. After discovering naked mole-rats, however, he became fascinated with their unique social structure and decided to study them instead.

African naked mole-rats live underground and never come out. They are tiny, toothy, and blind; they look like little pink sausages; and they smell bad. These creatures, the only mammals that are cold-blooded, typically live in big colonies, of 300 members, about six feet underground. Their narrow tunnels are extremely close, and their air supply is limited. The air they breathe is so toxic that it would kill or lead to irreversible brain damage in any other mammal.

Theirs is a cooperative organization where one female and several males are reproductively active, while the rest of the colony members divide up the chores, which include searching for food.

Naked mole-rats have one queen, who mates with up to three males--none of the others participates in reproduction. "They are very, very strange animals," Park said. "They are the only mammals with this bizarre social arrangement."

His research focus is on evolution, specifically how species adapt to challenges in their environment. Nevertheless, his work with these unusual mammals has produced new insights into pain response and oxygen deprivation that ultimately could lead to new approaches for treating these conditions, as well as brain injuries caused by heart attack, stroke or trauma.

Park and his colleague, John Larson, associate professor of physiology in psychiatry at UI-Chicago, have discovered that the brains of naked mole-rats can withstand oxygen deprivation--a condition known as hypoxia--for periods far greater than any other mammal. They also found that the rats are immune to certain types of pain, specifically the burning pain of acid, like lemon juice, and capsaicin, the spicy ingredient in chili peppers. The creatures naturally lack a neurotransmitter, Substance P, which communicates information about pain.

"Our working hypothesis is that insensitivity to acid is an adaptation to living in an acidic environment," Park said. "In their home tunnels, carbon dioxide builds up to unusually acidic levels. This is because naked mole-rats live in unusually large numbers for a subterranean species."

The pain findings arose from the researchers' attempt to figure out how mole-rats used the whisker-like hairs on their bodies, which are arranged in a grid-like pattern--ten rows with about ten hairs in each row. "This type of strict organization suggested that the hairs were patterned for a reason," Park said.

Touching the hairs, he realized that "the mole-rats can use these hairs to very accurately localize touch," he said. "Deflecting any one of the hairs triggers the mole-rat to bring its snout, and teeth, to the point of contact. This made sense to us, that an animal which is essentially blind and naturally lives in the dark would benefit from a superb sense of touch and special array of touch detectors arranged over the body."

Further study of the nerve cells and the different chemicals associated with these cells led the researchers to the missing Substance P.

In the lab environment, Park's mole-rats live in PVC piping that mimics the underground tunnels of their natural habitat. The pipes are connected to clear plastic boxes which the animals use to store food, gather, and go to the bathroom. They designate one spot as a toilet. The boxes are kept in sealed, climate controlled storage rooms where the humidity is high and the temperatures are in the 90s. A caretaker checks the humidity levels twice a day. The mole-rats seem to do well in this environment--they are even reproducing.

"I think they're happy," Park said. "We give them food in one chamber--they get a sweet potato every day--so if they want to take pieces back to their 'nest', they can. We give them treats as well; they really love squash. They also really love apple, because they don't drink anything, so they go nuts over anything that's sweet and juicy."

Speaking of apples, several years ago, during a study of mole-rat foraging behavior, the researchers set up large tubs with an inch or so of sand on the floor of each tub. They then cut up apples into tiny bits and buried them in the sand. They wanted to find out whether the mole-rats would communicate information to other mole-rats about the food, or keep the information to themselves.

"Some of the tubs would get a lot of apple bits, while other tubs would only get a few," he said. "Then we'd open a pipe to the mole-rat cage system and let them forage. At the end of each day, we counted how many bits of apple were left in each tub. To retrieve the apple bits, we poured the sand through a screen."

The problem was that the room was dim, lit only by red light, making it difficult for the researchers to tell the difference between the apple bits and mole-rat poop, which was the same size and shape.

"There was one occasion when a student was certain he had an apple bit," Park said. "It looked like apple, it felt like apple, but just to be sure--yes, he tasted it. It wasn't apple. From then on, we carried the sand out of the dimly lit room and counted apple bits in the well-lit hallway."

While the mole-rats in the lab are not pets, the researchers have grown to appreciate their individual characteristics. "I don't name them, but it's easy for me to distinguish one from another," Park said. "They all look like sausages, but some are chubby, others skinny, some have more wrinkles, some are pinker. In general, they are very gentle creatures, but they most definitely have different personalities. Some are more curious, some more timid, some more bossy to their peers."

Plants in the Desert, Plants Feel the Heat of Global Warming

Global warming is a hot topic, and it's causing concern for scientists studying winter annuals in the Sonoran Desert.

While desert winters have become warmer and drier over the years, climate changes have pushed the arrival of winter rains later in the year, forcing winter annual plants like the curvenut combseed (Pectocarya recurvata) to emerge later when temperatures are colder.

In 1982, Larry Venable, an ecologist at the University of Arizona (UA) in Tucson, began a study at the Desert Laboratory on nearby Tumamoc Hill in order to investigate adaptive "bet-hedging" in plants.

Bet-hedging is an adaptive response by seeds that allows them to delay germination. The germination delay can be caused by insufficient rainfall, lack of nutrients, inappropriate temperatures or any adverse condition that would affect the survival of a seed, and it allows a plant to improve chances of survival. The seeds can remain dormant for extended periods if the environment is unfavorable for germination and survival.

"No one had bothered to study real desert annuals to see what happens, and here I was, suddenly working as a plant ecologist in the middle of the desert," Venable said. "The theory involved plants that hedge against year-to-year variation in reproductive success, so I thought I'd set up some field plots and measure it."

The later arrival of Sonoran desert winter rains pushes the germination of the winter annuals later into the year and has affected the types of winter annuals that dominate the location. Researchers measure carbon and nitrogen in the plants' leaves to learn how well the various species grow at winter's lower temperatures.

"The species that we are calling 'cold-adapted' species have high lifetime-water-use efficiency (WUE), as measured with carbon isotopes," said study author Sarah Kimball, a research associate in UA's department of ecology and evolutionary biology and a colleague of Venable's. "They also have high amounts of nitrogen in their leaves. The high nitrogen, along with instantaneous gas exchange measurements, indicate the plants have a high investment in light-gathering capacity, which indicates a greater ability to photosynthesize under low temperatures," Kimball added.

The plant's greater ability to photosynthesize translates into a greater ability to use energy from sunlight and convert it into food, improving chances for survival. Venable and his colleagues found that plants with more efficient water storage are the species prevailing in the colder environment.

Tracking the progression of germination involves studying plots of soil as small as hundredths of a square meter.

"We check for germination by going out in the field several days after a rain event and looking for seedlings," Kimball said. "When germination occurs, we use acetate sheets to map the location of each individual."

"Mapping" involves the researchers getting on their knees and identifying each individual plant in the plot. The team places acetate sheets over the plots of soil, and the researchers make marks on the sheets to identify the location of each seedling.

The researchers identify the tiny plants by using the seedlings' embryonic first leaves, known as cotyledons. While the acquisition of the data sounds simple enough, it can be complicated.

"In wet years, when there is a high density of plants, the 'maps' that we make get very full, so each plot takes a long time and it can be difficult to be sure that we record every individual," Kimball said.

"Anticipating timing and insuring adequate work hours and materials are available at the right time to match the plants' growth events is difficult," Venable added.

The winter annuals are not the only vegetation affected by the climate shift occurring in the Sonoran desert. The increasingly drier climate has caused a decrease in dominant desert shrubbery as well. The lack of water available to the shrubs has caused them decrease in size so they can more efficiently utilize the amount of water that's available.

If the later arrival of winter rains continues, the germination of the winter annuals will subsequently occur later in the year, and the plant community will continuously change and favor plants that thrive in colder environments.

Eyjafjallajokull Volcano's Ash Plume Streaming Steadily

A visible image taken from the Moderate Imaging Spectroradiometer (MODIS) Instrument that flies aboard the satellite showed the ash plume streaming in a straighter, more steady path than the day before, indicating winds were stronger than they were May 9. The ash plume was moving in a south-southeasterly direction over the Northern Atlantic Ocean. Farther south in the image the ash plume became partially obscured by higher clouds (white). By May 10, the ash had reached North Africa, Turkey and Morocco.

STS-132 Astronauts Arrive at Kennedy for Launch on 14th

The six astronauts for space shuttle Atlantis' STS-132 mission to the International Space Station now are at NASA's Kennedy Space Center in Florida for their prelaunch preparations. The crew arrived at Kennedy's Shuttle Landing Facility in four T-38 jets at 6:49 p.m. EDT. STS-138 Commander Ken Ham made a brief statement to media who were gathered at the SLF for the arrival, and then he and his crew departed the shuttle runway.

The crew is scheduled to go to sleep at 9 p.m. and wake up Tuesday at 5:15 a.m. Ham and Pilot Tony Antonelli then will practice shuttle landings starting at 6 a.m. in Shuttle Training Aircraft, which are modified Gulfstream II jets.

Black Holes observed by Chandra X-ray May Be Mid-Sized

New evidence from NASA's Chandra X-ray Observatory and ESA's XMM-Newton strengthens the case that two mid-sized black holes exist close to the center of a nearby starburst galaxy. These “survivor” black holes avoided falling into the center of the galaxy and could be examples of the seeds required for the growth of supermassive black holes in galaxies, including the one in the Milky Way.

For several decades, scientists have had strong evidence for two distinct classes of black hole: the stellar-mass variety with masses about ten times that of the Sun, and the supermassive ones, located at the center of galaxies, that range from hundreds of thousands to billions of solar masses.

But a mystery has remained: what about black holes that are in between? Evidence for these objects has remained controversial, and until now there were no strong claims of more than one such black hole in a single galaxy. Recently, a team of researchers has found signatures in X-ray data of two mid-sized black holes in the starburst galaxy M82 located 12 million light years from Earth.

"This is the first time that good evidence for two mid-sized black holes has been found in one galaxy," said Hua Feng of the Tsinghua University in China, who led two papers describing the results. "Their location near the center of the galaxy might provide clues about the origin of the Universe's largest black holes -- supermassive black holes found in the centers of most galaxies."

One possible mechanism for the formation of supermassive black holes involves a chain reaction of collisions of stars in compact star clusters that results in the buildup of extremely massive stars, which then collapse to form intermediate-mass black holes. The star clusters then sink to the center of the galaxy, where the intermediate-mass black holes merge to form a supermassive black hole.

In this picture, clusters that were not massive enough or close enough to the center of the galaxy to fall in would survive, as would any black holes they contain.

"We can't say whether this process actually occurred in M82, but we do know that both of these possible mid-sized black holes are located in or near star clusters," said Phil Kaaret from the University of Iowa, who co-authored both papers. "Also, M82 is the nearest place to us where the conditions are similar to those in the early Universe, with lots of stars forming."

The evidence for these two "survivor" black holes comes from how their X-ray emission varies over time and analysis of their X-ray brightness and spectra, i.e., the distribution of X-rays with energy.

Chandra and XMM-Newton data show that the X-ray emission for one of these objects changes in a distinctive manner similar to stellar-mass black holes found in the Milky Way. Using this information and theoretical models, the team estimated this black hole's mass is between 12,000 and 43,000 times the mass of the Sun. This mass is large enough for the black hole to generate copious X-rays by pulling gas directly from its surroundings, rather than from a binary companion, like with stellar-mass black holes.

The black hole is located at a projected distance of 290 light years from the center of M82. The authors estimate that, at this close distance, if the black hole was born at the same time as the galaxy and its mass was more than about 30,000 solar masses it would have been pulled into the center of the galaxy. That is, it may have just escaped falling into the supermassive black hole that is presumably located in the center of M82.

The second object, located 600 light years in projection away from the center of M82, was observed by both Chandra and XMM-Newton. During X-ray outbursts, periodic and random variations normally present in the X-ray emission disappear, a strong indication that a disk of hot gas dominates the X-ray emission. A detailed fit of the X-ray data indicates that the disk extends all the way to the innermost stable orbit around the black hole. Similar behavior has been seen from stellar-mass black holes in our Galaxy, but this is the first likely detection in a candidate intermediate-mass black hole.

The radius of the innermost stable orbit depends only on the mass and spin of the black hole. The best model for the X-ray emission implies a rapidly spinning black hole with mass in the range 200 to 800 times the mass of the Sun. The mass agrees with theoretical estimates for a black hole created in a star cluster by runaway collisions of stars.

"This result is one of the strongest pieces of evidence to date for the existence of an intermediate-mass black hole," said Feng. "This looks just like well-studied examples of stellar-mass black holes, except for being more than 20 times as massive."

The two papers describing these results recently appeared in The Astrophysical Journal. 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.

The XMM-Newton spacecraft is controlled by the European Space Operations Center. The XMM-Newton Science Operations Center situated at ESAC in Villafranca, Spain, manages observation requests and receives XMM-Newton data. The XMM-Newton Survey Science Centre at Leicester University, UK, processes and correlates all XMM-Newton observations with existing sky data held elsewhere in the world.

Juno Mission Overview

Juno’s principal goal is to understand the origin and evolution of Jupiter. Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our solar system during its formation. As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars.

With its suite of science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras.

Juno will let us take a giant step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system.

Jupiter’s Origins and Interior

Theories about solar system formation all begin with the collapse of a giant cloud of gas and dust, or nebula, most of which formed the infant sun. Like the sun, Jupiter is mostly hydrogen and helium, so it must have formed early, capturing most of the material left after our star came to be. How this happened, however, is unclear. Did a massive planetary core form first and gravitationally capture all that gas, or did an unstable region collapse inside the nebula, triggering the planet’s formation? Differences between these scenarios are profound.

Even more importantly, the composition and role of icy planetesimals, or small proto-planets, in planetary formation hangs in the balance – and with them, the origin of Earth and other terrestrial planets. Icy planetesimals likely were the carriers of materials like water and carbon compounds that are the fundamental building blocks of life.

Unlike Earth, Jupiter's giant mass allowed it to hold onto its original composition, providing us with a way of tracing our solar system's history. Juno will measure the amount of water and ammonia in Jupiter’s atmosphere and determine if the planet actually has a solid core, directly resolving the origin of this giant planet and thereby the solar system. By mapping Jupiter’s gravitational and magnetic fields, Juno will reveal the planet’s interior structure and measure the mass of the core.


Atmosphere

How deep Jupiter's colorful zones, belts, and other features penetrate is one of the most outstanding fundamental questions about the giant planet. Juno will determine the global structure and motions of the planet’s atmosphere below the cloud tops for the first time, mapping variations in the atmosphere’s composition, temperature, clouds and patterns of movement down to unprecedented depths.

Magnetosphere

Deep in Jupiter's atmosphere, under great pressure, hydrogen gas is squeezed into a fluid known as metallic hydrogen. At these great depths, the hydrogen acts like an electrically conducting metal which is believed to be the source of the planet's intense magnetic field. This powerful magnetic environment creates the brightest auroras in our solar system, as charged particles precipitate down into the planet’s atmosphere. Juno will directly sample the charged particles and magnetic fields near Jupiter’s poles for the first time, while simultaneously observing the auroras in ultraviolet light produced by the extraordinary amounts of energy crashing into the polar regions. These investigations will greatly improve our understanding of this remarkable phenomenon, and also of similar magnetic objects, like young stars with their own planetary systems.

Juno’s Mythical Connection

In Greek and Roman mythology, Jupiter drew a veil of clouds around himself to hide his mischief. It was Jupiter's wife, the goddess Juno, who was able to peer through the clouds and reveal Jupiter’s true nature. The Juno spacecraft will also look beneath the clouds to see what the planet is up to, not seeking signs of misbehavior, but helping us to understand the planet’s structure and history.

Mission Timeline

* Launch - August 2011
* Earth flyby gravity assist - October 2013
* Jupiter arrival - July 2016
* End of mission (deorbit) - October 2017

The Juno mission is the second spacecraft designed under NASA's New Frontiers Program. The first was the Pluto New Horizons mission, launched in January 2006 and scheduled to reach Pluto's moon Charon in 2015. The program provides opportunities to carry out several medium-class missions identified as top priority objectives in the Decadal Solar System Exploration Survey, conducted by the Space Studies Board of the National Research Council in Washington.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Juno mission. The Principal Investigator is Dr. Scott Bolton of Southwest Research Institute in San Antonio, Texas. Lockheed Martin of Denver is building the spacecraft. The Italian Space Agency is contributing an infrared spectrometer instrument and a portion of the radio science experiment.

What's in the Glaciers Water

Being on top of an Alaskan glacier was not as cold as Michael Nassry expected.

Nassry grew up hunting, fishing, hiking and camping in western Pennsylvania, near his home in Hopwood. "I like the outdoors," he said.

With that motivation, he decided he wanted to be an environmental engineer, and found himself in the agricultural and biological engineering program at Penn State University, where he focused on soils and water research. Now a doctoral student in biological systems engineering at Virginia Tech, he has fine-tuned his interest to nutrient transport in rivers and streams.

"I look at what is taken up, what is used, what is passed through to down-river systems," he said, referring to the nutrients in waterways that exercise tremendous control over whether aquatic life thrives, or collapses. He is guided in this focus by his advisor, Durelle "Scotty" Scott.

"Scotty has a lot of projects going on, but I was attracted to the Alaska project because I haven't had a lot of exposure to glacial systems," Nassry said. "What is happening to these watersheds is a hot topic."

"Within a small area, you can examine watersheds that range in glacial coverage," Scott said. "This allows us to look at how these systems respond to climate change."

Nassry traveled to Alaska with Scott and undergraduate student Andrew Jeffrey, who has since graduated, to join Eran Hood, associate professor of hydrology at the University of Alaska Southeast, and his two students, for two weeks in July 2009. It was all part of Scott's National Science Foundation- (NSF) funded research to measure the movement of nutrients out of glaciers.

All of the study sites were close to, and accessible from, Juneau, and the July period, when the glaciers are melting, offered better weather for the helicopters carrying the researchers to the glacier tops.

In addition to the milder-than-expected temperatures, Nassry was surprised at how quickly the ice melted around the ground covers the scientists slept on. "When we picked up the tarp, the ice underneath was about an inch higher than the surrounding ice." Nassry also noticed a lot of streams on top of the glacier, some of them large. "I didn't expect so much surface flow," he added. "I thought more melt would be through the ice."

The research team was atop the ice to perform an injection experiment. First, they put dye in a stream so they could measure its speed. The next day, for three hours straight, they injected a salt solution and several other solutions containing nutrients into the stream. The team then collected water samples at three downstream locations, after the injection pumps were turned off, to determine what flowed out and what was absorbed. Nassry's jobs were to calibrate the injection pumps and collect background samples above the injection point.

The task and clean-up took until 10 or 11 p.m., by which time the helicopters had quit for the day, so the researchers slept on the ice--or not. "It was so bright, I couldn't sleep at all," Nassry said. Hood had been prepared for the overnight and provided the sleeping bags. The one Nassry used came complete with teddy bear, having previously been used by Hood's young daughter.

The next task was to sample the base of the different watersheds, some of which had more glacial coverage than others. "For the Lemon Glacier, Andrew, Eran, Scotty and I were dropped at the face by a helicopter early in the morning; then, we sampled and hiked the whole length of Lemon Creek--six to eight hours," Nassry said.

"Scotty and Andrew biked up a path to the Herbert Glacier and sampled the stream on the way back. And Eran and I hiked a trail at Montana Creek and sampled on the way down. That only took a few hours," Nassry said. The Mendenhall River is shrinking at a far more rapid pace, as evidenced by data from its stream gauges.

"Eran analyzed samples for carbon in his lab and shipped us the remaining samples," Nassry said. "In Scotty's lab, we're measuring nutrients, carbon, anions and water isotopes. We used a U.S. Geological Survey computer model, called OTIS, to simulate the downstream flow of water and salts along the reach. Once we achieved a calibrated model for the salts, we knew the hydrology--or what the water was doing. Our next step is to apply the model to each of the biologically available nutrients added during the injection experiment."

In summer 2010, the researchers, including Nassry, will work in streams between the glaciers and the gulf. "This spring," Nassry said, "I'll be designing those experiments and testing them in Stroubles Creek [near the Virginia Tech campus]."

And when they head back, the summer 2010 team will include a local K-12 teacher so that she can learn what it's like to do environmental research--experiences she can share with other teachers and her students.

Coupled Ion Neutral Dynamic Investigation(CINDI) Hunts Giant, Radio-Busting Plasma Bubbles

They come out at night over the equator -- giant bubbles of plasma, a gas of electrically charged particles, silently rise in the upper atmosphere. While invisible to human eyes, they can disrupt crucial radio communication and navigation signals, like the Global Positioning System (GPS). NASA is collaborating with the Air Force on a unique investigation that will study how these bubbles form by conducting the Coupled Ion Neutral Dynamic Investigation (CINDI) as part of the payload for the Air Force Communication/Navigation Outage Forecast System satellite.

"Understanding when and where plasma bubbles occur, how severe they will be and how long they will last is vitally important since interference from plasma bubbles affects GPS signals and other radio signals that can travel around the globe by reflection from layers in Earth's upper atmosphere, called the thermosphere and the ionosphere," said CINDI Principal Investigator Prof. Rod Heelis of the University of Texas at Dallas. "These signals are used for communication and navigation by a wide variety of commercial and government entities including the Federal Aviation Administration and search and rescue operations. Most of us are directly or indirectly dependent on the proper function of these space-based systems and it is imperative that we attempt to predict the times when such systems may not be reliable."

Plasma bubbles form at night because the thermosphere and ionosphere have a mix of plasma and electrically neutral gas which becomes unstable after sunset. During the daytime, radiation from the sun creates plasma by tearing electrons from atoms and molecules in the thermosphere and ionosphere. The solar radiation maintains relatively constant levels of plasma in these regions, so they are quite smooth and well behaved. But during the nighttime, there is no solar radiation to prevent the charged particles from recombining back into electrically neutral atoms or molecules again.

The recombination happens faster at lower altitudes, because there are more heavy charged particles (molecular ions) there, and they recombine more quickly than charged particles made from single atoms. More rapid recombination makes the plasma less dense at lower altitudes. The region then becomes unstable because the less dense plasma below, which is trapped in the neutral gas, wants to rise above the higher density plasma above it.

This nighttime instability actually happens at all latitudes, but the equatorial regions become especially turbulent because the plasma bubbles are suspended on Earth's magnetic field, which is horizontal over the equator.

When the overturning starts, the low-density plasma rises to the top of the region, much like air bubbles in water. Scientists use the term equatorial plasma bubbles to describe these regions of low-density charged particles. The boundaries of these equatorial plasma bubbles are where the communication and navigation signals are interrupted. However, at the present time we do not know when these plasma bubbles will appear or how large a region they will occupy.

Scientists aren't sure exactly what triggers the rise of the plasma bubbles. One theory is that winds in the upper atmosphere play a role. CINDI is designed to fly through these regions and determine the conditions that exist just prior to the onset of plasma bubbles and how their evolution is related to these conditions.

The CINDI mission will simultaneously explore the motions of the charged and neutral gases for the first time, and will discover the differences in their behavior when plasma bubbles form and when they do not. This information will help explain the fundamental relationships between charged and neutral particles, allowing scientists to build a better forecast model for plasma bubbles for use in the Earth’s environment and in other planetary environments as well.

The CINDI investigation is a critical part of the science objectives of the Communication/Navigation Outage Forecast System (C/NOFS) satellite undertaken by the Air Force Research Laboratory and the Space and Missile Command Test and Evaluation Directorate. CINDI consists of two instruments on-board the satellite, the Ion Velocity Meter (IVM) and the Neutral Wind Meter (NWM), which separately measure the ionized (electrically charged) and neutral particles that exist in the ionosphere.

CINDI and the C/NOFS satellite will be launched April 16, 2008, on a Pegasus XL rocket carried aboard Orbital Science Corporation's L-1011 "Stargazer" jet. The Pegasus starts its mission secured to the belly of the L-1011, where it’s carried to the planned launch altitude. Using the Stargazer again and again saves money by eliminating the need for a first stage motor to lift each Pegasus off the ground. The C/NOFS spacecraft was launched into an equatorial orbit that ranges from 250 to 530 miles (400 to 850 kilometers) in altitude, and it is scheduled to collect data for two years.

CINDI is a NASA sponsored Mission of Opportunity conducted by the University of Texas at Dallas (UTD). NASA’s Explorer Program at Goddard Space Flight Center, Greenbelt, Md., manages the CINDI mission. The Explorer’s Program provides frequent flight opportunities for world-class scientific investigations from space within heliophysics and astrophysics.

Hubble's Universe in 3-D

This image depicts a vast canyon of dust and gas in the Orion Nebula from a 3-D computer model based on observations by NASA's Hubble Space Telescope and created by science visualization specialists at the Space Telescope Science Institute (STScI) in Baltimore, Md. A 3-D visualization of this model takes viewers on an amazing four-minute voyage through the 15-light-year-wide canyon.

The model takes viewers through an exhilarating ride through the Orion Nebula, a vast star-making factory 1,500 light-years away. This virtual space journey isn't the latest video game but one of several groundbreaking astronomy visualizations created by specialists at STScI, the science operations center for NASA's Hubble Space Telescope. The cinematic space odysseys are part of the new Imax film Hubble 3D, which opens today at select IMAX theaters worldwide.

The 43-minute movie chronicles the 20-year life of Hubble and includes highlights from the May 2009 servicing mission to the Earth-orbiting observatory, with footage taken by the astronauts. The giant-screen film showcases some of Hubble's breathtaking iconic pictures, such as the Eagle Nebula's "Pillars of Creation," as well as stunning views taken by the newly installed Wide Field Camera 3.

While Hubble pictures of celestial objects are awe-inspiring, they are flat 2-D photographs. For this film, those 2-D images have been converted into 3-D environments, giving the audience the impression they are space travelers taking a tour of Hubble's most popular targets.

Based on a Hubble image of Orion released in 2006, the visualization was a collaborative effort between science visualization specialists at STScI, including Greg Bacon, who sculpted the Orion Nebula digital model, with input from STScI astronomer Massimo Roberto; the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign; and the Spitzer Science Center at the California Institute of Technology in Pasadena.

Chandra X-ray Observatory shows Double Black Holes

This image from the Chandra X-ray Observatory shows the central region of the starburst galaxy M82 and contains two bright X-ray sources of special interest. New studies with Chandra and ESA's XMM-Newton show that these two sources may be intermediate-mass black holes, with masses in between those of the stellar-mass and supermassive variety. These "survivor" black holes avoided falling into the center of the galaxy and could be examples of the seeds required for the growth of supermassive black holes in galaxies, including the one in the Milky Way.

This is the first case where good evidence for more than one mid-sized black hole exists in a single galaxy. The evidence comes from how their X-ray emission varies over time and analysis of their X-ray brightness and spectra, i.e., the distribution of X-rays with energy. These results are interesting because they may help address the mystery of how supermassive black holes in the centers of galaxies form. M82 is located about 12 million light years from Earth and is the nearest place to us where the conditions are similar to those in the early Universe, with lots of stars forming.

Multiple observations of M82 have been made with Chandra beginning soon after launch. The Chandra data shown here were not used in the new research because the X-ray sources are so bright that some distortion is introduced into the X-ray spectra. To combat this, the pointing of Chandra is changed so that images of the sources are deliberately blurred, producing fewer counts in each pixel.