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Showing posts with label ASTRONOMY. Show all posts
Showing posts with label ASTRONOMY. Show all posts

UCLA and CASIS to collaborate on International Space Station study of possible therapy for bone loss

Written By Unknown on Saturday, January 31, 2015 | 7:38 PM

A study of rodents on the International Space Station will allow astronauts to test the ability of a bone-forming molecule to direct stem cells to induce bone formation. Credit: Nasa
UCLA has received grant funding from the Center for the Advancement of Science in Space to lead a research mission that will send rodents to the International Space Station. The mission will allow astronauts on the space station and scientists on Earth to test a potential new therapy for accelerating bone growth in humans. 

The research will be led by Dr. Chia Soo, a UCLA professor of plastic and reconstructive surgery and orthopaedic surgery who is member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research. Soo also is the research director for UCLA Operation Mend, which provides medical care for wounded warriors.

The study will test the ability of a bone-forming molecule called NELL-1 to direct stem cells to induce bone formation and prevent bone degeneration. Their work will build upon previous UCLA studies that were funded by the NIH.

Other members of the UCLA research team are Dr. Kang Ting, a professor of dentistry who discovered NELL-1 and is leading efforts to translate NELL-1 therapy to humans; Dr. Ben Wu, a professor of bioengineering and dentistry who modified the NELL-1 molecule to make it useful for treating osteoporosis; and Dr. Jin Hee Kwak, an assistant professor of dentistry who will manage the study’s daily operations.

Prolonged space flights induce extreme changes in bone and organ systems that cannot be replicated on Earth.

The UCLA–ISS team, which will begin ground operations in early 2015, hopes that the study will provide new insights into the prevention of bone loss or osteoporosis as well as the regeneration of massive bone defects that can occur in wounded military personnel. Osteoporosis is a significant health issue commonly associated with “skeletal disuse” conditions such as immobilization, stroke, cerebral palsy, muscular dystrophy, spinal cord injury and jaw resorption after tooth loss.

“NELL-1 holds tremendous hope not only for preventing bone loss, but one day even restoring healthy bone,” Ting said. “For patients who are bed-bound and suffering from bone loss, it could be life-changing.” 

The UCLA team will oversee the ground operations of the mission in tandem with a flight operation coordinated by CASIS and NASA.  

“A group of 40 rodents will be sent to the International Space Station U.S. National Laboratory onboard the SpaceX Dragon capsule, where they will live for two months in a microgravity environment during the first ever test of NELL-1 in space,” said Dr. Julie Robinson, NASA’s chief scientist for the International Space Station program at the Johnson Space Center.

“CASIS is proud to work alongside UCLA in an effort to promote the station as a viable platform for bone loss inquiry,” said Warren Bates, director of portfolio management for CASIS. “Through investigations like this, we hope to make profound discoveries and enable the development of therapies to counteract bone loss ailments common in humans.”

“Besides testing the limits of NELL-1’s robust bone-producing effects, this mission will provide new insights about bone biology and could uncover important clues for curing diseases such as osteoporosis,” Wu said. 

“NIH has been pleased to work with NASA and CASIS to encourage the use of the International Space Station as a unique microgravity environment that can test innovative hypotheses that will benefit human health on Earth,” said Dr. Joan A. McGowan, director of the division of musculoskeletal diseases at the National Institute of Arthritis and Musculoskeletal and Skin Diseases, part of the NIH.

“This research has enormous translational application for astronauts in space flight and for patients on Earth who have osteoporosis or other bone-loss problems from disease, illness or trauma,” Soo said. “We very much appreciate the dedicated review staff at CASIS and the Center for Scientific Review, the portal for NIH grant applications, who made this effort possible.”

The research is supported by grants from the Center for the Advancement of Science in Space and National Institutes of Health. Additional funding and support are provided by the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, the UCLA School of Dentistry, UCLA department of orthopaedic surgery and the UCLA Orthopaedic Hospital Research Center.

Source: UCLA

Helicopter Could Be 'Scout' for Mars Rovers

Enter the Mars Helicopter, a proposed add-on to Mars rovers of the future that could potentially triple the distance these vehicles currently drive in a Martian day, and deliver a new level of visual information for choosing which sites to explore.

The helicopter would fly ahead of the rover almost every day, checking out various possible points of interest and helping engineers back on Earth plan the best driving route.

Scientists could also use the helicopter images to look for features for the rover to study in further detail. Another part of the helicopter's job would be to check out the best places for the rover to collect key samples and rocks for a cache, which a next-generation rover could pick up later.

The vehicle is envisioned to weigh 2.2 pounds (1 kilogram) and measure 3.6 feet (1.1 meters) across from the tip of one blade to the other. The prototype body looks like a medium-size cubic tissue box.

The current design is a proof-of-concept technology demonstration that has been tested at NASA's Jet Propulsion Laboratory, Pasadena, California.

Source: Nasa

NASA's Dawn Spacecraft Captures Best-Ever View of Dwarf Planet

This animation of the dwarf planet Ceres was made by combining images taken by the Dawn spacecraft on January 25, 2015.
NASA's Dawn spacecraft has returned the sharpest images ever seen of the dwarf planet Ceres. The images were taken 147,000 miles (237,000 kilometers) from Ceres on Jan. 25, and represent a new milestone for a spacecraft that soon will become the first human-made probe to visit a dwarf planet.

"We know so little about our vast solar system, but thanks to economical missions like Dawn, those mysteries are being solved," said Jim Green, Planetary Science Division Director at NASA Headquarters in Washington.

At 43 pixels wide, the new images are more than 30 percent higher in resolution than those taken by NASA's Hubble Space Telescope in 2003 and 2004 at a distance of over 150 million miles (about 241 million kilometers). The resolution is higher because Dawn is traveling through the solar system to Ceres, while Hubble remains fixed in Earth orbit. The new Dawn images come on the heels of initial navigation images taken Jan. 13 that reveal a white spot on the dwarf planet and the suggestion of craters. Hubble images also had glimpsed a white spot on the dwarf planet, but its nature is still unknown.

"Ceres is a 'planet' that you've probably never heard of," said Robert Mase, Dawn project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "We're excited to learn all about it with Dawn and share our discoveries with the world."

As the spacecraft gets closer to Ceres, its camera will return even better images. On March 6, Dawn will enter into orbit around Ceres to capture detailed images and measure variations in light reflected from Ceres, which should reveal the planet's surface composition.

"We are already seeing areas and details on Ceres popping out that had not been seen before. For instance, there are several dark features in the southern hemisphere that might be craters within a region that is darker overall," said Carol Raymond, deputy principal investigator of the Dawn mission at JPL. "Data from this mission will revolutionize our understanding of this unique body. Ceres is showing us tantalizing features that are whetting our appetite for the detailed exploration to come."

Ceres, the largest body between Mars and Jupiter in the main asteroid belt, has a diameter of about 590 miles (950 kilometers). Some scientists believe the dwarf planet harbored a subsurface ocean in the past and liquid water may still be lurking under its icy mantle.

Originally described as a planet, Ceres was later categorized as an asteroid, and then reclassified as a dwarf planet in 2006. The mysterious world was discovered in 1801 by astronomer Giuseppe Piazzi, who named the object for the Roman goddess of agriculture, grain crops, fertility and motherly relationships.

"You may not realize that the word 'cereal' comes from the name Ceres. Perhaps you already connected with the dwarf planet at breakfast today," said JPL's Marc Rayman, mission director and chief engineer of the Dawn mission.

Powered by a uniquely capable ion propulsion system, Dawn also orbited and explored Vesta, the second most massive body in the asteroid belt. From 2011 to 2012, Dawn returned more than 30,000 images, 18 million light measurements and other scientific data about the impressive large asteroid. Vesta has a diameter of about 326 miles (525 kilometers).

"With the help of Dawn and other missions, we are continually adding to our understanding of how the solar system began and how the planets were formed," said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Virginia, designed and built the spacecraft. JPL is managed for NASA by the California Institute of Technology in Pasadena.

The framing cameras were provided by the Max Planck Institute for Solar System Research in Gottingen, Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research in Berlin, and in coordination with the Institute of Computer and Communication Network Engineering in Braunschweig.

The visible and infrared mapping spectrometer was provided by the Italian Space Agency and the Italian National Institute for Astrophysics, was built by Selex ES, and is managed by Italy's National Institute for Astrophysics and Planetology in Rome. The gamma ray and neutron detector was built by Los Alamos National Laboratory in New Mexico, and is operated by the Planetary Science Institute of Tucson, Arizona.

Source: Nasa

The Ancient exoplanet discovery boosts chances of finding alien life

Written By Unknown on Friday, January 30, 2015 | 5:26 AM

An artist's impression of the oldest known system of terrestrial-sized planets, Kepler-444. Tiago Campante/Peter Devine, University of Birmingham, Author provided Credit: By Daniel Huber, Astronomer at University of Sydney
One of the crucial variables in calculating the likelihood that alien life exists elsewhere in our galaxy is the number of stars that possess planetary systems, and the proportion of those planets that might be suitable for life.

So the discovery of no less than five sub-Earth-sized exoplanets orbiting an ancient star, Kepler-444, which is not too distant from our own solar system, has significant ramifications for the possibility we might one day run into ET.

Formed over 11-billion years ago, the Kepler-444 system proves that such small planets have existed through most of the history of our universe. And the more small planets that exist, the higher the chances that one of them (or one of their moons) might sit in the so-called “Goldilocks zone” that enables life to exist.

This remarkable discovery was made possible not only by the space-based NASA Kepler telescope but also a technique called asteroseismology.

Kepler continuously measured the brightness of more than 150,000 stars for four years. As planets orbit in front of the stellar disc they cause small dips in the brightness of the star, yielding information on the planet’s orbital period and size relative to the size of their host star.

More than 1,800 exoplanets have been discovered to date, including some Earth-sized planets in the habitable zone. Such discoveries have demonstrated that planets with favourable conditions for life may actually be common.

But the age of the host stars – and therefore the age of the planets – was often unknown. This is because the clues that give a hint to the age of a star tend to be hidden beneath its visible surface.

Using asteroseismology to date a star
An artist’s impression of Kepler-10, illustrating the paths of sound waves in the stellar interior which can be used to determine the fundamental properties – including age – of planet host stars. Gabriel Perez Diaz, Instituto de Astrofisica de Canarias
Fortunately, the variability in the brightness of stars offers a way to resolve this problem using asteroseismology.

Stars with similar and cooler temperatures than our sun transport energy to their surface through the up-flow and down-flow of gas that flows due to the interplay of buoyancy and gravity. The turbulent motion of the gas excites pressure waves to travel through the stellar interior.

The frequency of these waves – also referred to as oscillations – are determined by the sound speed, which in turn depends on the stellar interior structure and composition.

These oscillations also travel to different depths within the star, thereby offering a way to probe the structure by observing the oscillations. As the core properties of the star change with time, such changes are imprinted in the oscillation frequency patterns.

Conveniently, we can measure stellar oscillations using the same data we use to discover transiting planets. Thus we were able to use asteroseismology to study a fascinating planetary system in exquisite detail and to determine the age of the host star.


Kepler-444: An ancient laboratory for planetary and stellar astrophysics
Comparison of the sizes of inner solar system planets to the planets discovered in the Kepler-444 system. Daniel Huber & NASA
Unlike our solar system, however, the Kepler-444 planets orbit their host star in less than 10 days. Even taking into account the cooler temperature of Kepler-444 compared to our sun, this places these ancient planets well outside the habitable zone.

Despite the rather hostile environment, Kepler-444 marks an important milestone to understand whether life may be common outside the solar system. While the Kepler mission has previously demonstrated that small planets are abundant, Kepler-444 proves that such planets have formed for most of the history of our universe.

If life can form on Earth-sized planets in the habitable zone of other stars, this implies that it may have formed on distant planets long before life emerged here on Earth.

Source: University of Sydney

Gully patterns document Martian climate cycles

Written By Unknown on Thursday, January 29, 2015 | 5:13 AM

Martian gullies, old and new Sharp-featured, relatively recent gullies (blue arrows) and degraded older gullies (gold) in the same location on the surface of Mars suggest multiple episodes of liquid water flow, consistent with cyclical climate change on the Red Planet. Image: NASA HiRISE
Gullies carved into impact craters on Mars provide a window into climate change on the Red Planet. A new analysis suggests Mars has undergone several ice ages in the last several million years. The driver of these climate swings is likely the Red Planet's wobbly axis tilt.

PROVIDENCE, R.I. [Brown University] — Geologists from Brown University have found new evidence that glacier-like ice deposits advanced and retreated multiple times in the midlatitude regions of Mars in the relatively recent past.

For the study, in press in the journal Icarus, the researchers looked at hundreds of gully-like features found on the walls of impact craters throughout the Martian midlatitudes. They conclude that many of those gullies were formed by meltwater from icy deposits, which are known to have covered the Martian midlatitudes within the last 2 million years. The study also turned up evidence of multiple gully-forming events, suggesting that these ice deposits waxed and waned several times over the last several million years — relatively recently in Mars’ 4.5-billion year history.

“These recent climate cycles have been predicted by computer models, but have not been documented with widespread geological evidence until now,” said Jay Dickson, a researcher at Brown and the study’s lead author. “This research shows that gullies have been episodic across the entire southern hemisphere, a distribution that is required for this to be a signal of global climate change.”

Wobbly axis

At present, most of the water ice on Mars is concentrated at its poles, but there’s a wealth of evidence that it wasn’t always that way. In 2003, research led by Brown geologists James Head and Jack Mustard showed that the midlatitude regions of Mars are draped to varying degrees by layers of ice-rich soil and dust. Landforms in and around the deposits, termed the “latitude-dependent mantle,” look remarkably similar to glacial terrains found here on Earth. The deposits suggest the presence of thin glacier-like ice deposits sometime between 400,000 and 2 million years ago.

The researchers concluded that this recent Martian ice age was likely linked to the planet’s wobbly rotation around its axis. Currently, the angle of Mars’ axis — its obliquity — is about 25 degrees, fairly close to that of Earth. But because Mars lacks a large moon to stabilize its rotation, its recent obliquity oscillates between around 15 degrees and as much as 35 degrees. (Earth’s obliquity, in contrast, varies only 2.4 degrees). Computer models predict that when the obliquity of Mars exceeds 30 degrees, increased sunlight at the poles causes water in the ice caps to be freed into the atmosphere. That water is transported and deposited closer to the equator in the form of glacial snow and ice.

Mars is known to have crossed the 30-degree threshold in obliquity several times during the last 20 million years. So if obliquity drives ice ages, there should be evidence for multiple glacial periods in the Martian midlatitudes, and that’s what the researchers were looking for in this latest study.

Gullies old and new

The researchers looked at detailed images taken by NASA’s High Resolution Imaging Science Experiment (HiRISE) of 479 gullies in the midlatitudes of Mars’ southern hemisphere. The gully systems, which form on steep crater walls, consist of an alcove at the top from which sediment is excavated, a channel through which material is carried, and a delta-like fan at the bottom where material is deposited.

The survey showed gully systems in various states of erosion and degradation. In some places, older gully fans, eroded over many years by the elements, had been crosscut by new gully fan systems. That suggests at least two gully-carving events. In other examples, gully fans were clearly visible, but the alcoves and channels that supplied them had disappeared, covered by a new layer of ice-rich soil. That too suggests multiple periods of glacial deposition.

“We show solid evidence of at least two periods of emplacement of the latitude-dependent mantle,” said Head, an author on the new paper. “That’s consistent with the idea of cyclical ice ages on Mars related to its obliquity.”

The work also bolsters the idea the many of gullies were carved by flows of liquid water. In recent years researchers have shown that some of these gully systems are still active today, when the flow of liquid water is unlikely. The present-day activity is likely driven by CO2 frost, which evaporates from the soil causing rock and rubble to slide down slopes. But this latest study shows that gullies were active when obliquity was higher and CO2 frost would have been sparse. And the association of gullies with ice-rich deposits strongly suggests that water carved these older gullies.

“We see similar features in Antarctica,” Head said. “Despite cold air temperatures, the sun is able to heat ice just enough for melting and gully activity to occur.”

This and other research pointing to relatively recent ice ages on Mars suggest the midlatitudes of Mars could be a place to look for signs of past life, Head said.

“I think people have this idea of Mars as an inactive place, that it is now as it has been for billions of years,” he said. “But it seems likely that climate cycles and global climate change are still occurring.”

Source: Brown University

Black hole on a diet creates a 'changing look' quasar

This artist's rending shows "before" and "after" images of a changing look quasar.
Credit: By Jim Shelton
Yale University astronomers have identified the first “changing look” quasar, a gleaming object in deep space that appears to have its own dimmer switch.

The discovery may offer a glimpse into the life story of the universe’s great beacons.

Quasars are massive, luminous objects that draw their energy from black holes. Until now, scientists have been unable to study both the bright and dim phases of a quasar in a single source.

As described in an upcoming edition of The Astrophysical Journal, Yale-led researchers spotted a quasar that had dimmed by a factor of six or seven, compared with observations from a few years earlier.

“We’ve looked at hundreds of thousands of quasars at this point, and now we’ve found one that has switched off,” said C. Megan Urry, Yale’s Israel Munson Professor of Astronomy and Astrophysics, and the study’s co-author. “This may tell us something about their lifetimes.”

Stephanie LaMassa, a Yale associate research scientist and principal investigator for the study, noticed the phenomenon during an ongoing probe of Stripe 82 — a sliver of the sky found along the Celestial Equator. Stripe 82 has been scanned in numerous astronomical surveys, including the Sloan Digital Sky Survey.

“This is like a dimmer switch,” LaMassa said. “The power source just went dim. Because the life cycle of a quasar is one of the big unknowns, catching one as it changes, within a human lifetime, is amazing.”

Even more significant for astronomers was the weakening of the quasar’s broad emission lines. Visible on the optical spectrum, these broad emission lines are signatures of gas that is too distant to be consumed by a black hole, yet close enough to be “excited” by energy from material that does fall into a black hole.

The change in the emission lines is what told researchers that the black hole had essentially gone on a diet, and was giving off less energy as a result. That’s when the “changing look” quasar hit its dimmer switch, and most of its broad emission lines disappeared.

The Yale team analyzed a variety of observation data, including recent optical spectra information and archival optical photometry and X-ray spectra information. They needed to rule out the possibility the quasar merely appeared to lose brightness, due to a gas cloud or other object passing in front of it.

The findings may prove invaluable on several fronts. First, they provide direct information about the intermittent nature of quasar activity; even more intriguingly, they hint at the sporadic activity of black holes.

“It makes a difference to know how black holes grow,” Urry said, noting that all galaxies have black holes, and quasars are a phase that black holes go through before becoming dormant. “This perhaps has implications for how the Milky Way looks today.”

Additionally, there is the chance the quasar may fire up again, showing astronomers yet another changing look.

“Even though astronomers have been studying quasars for more than 50 years, it’s exciting that someone like me, who has studied black holes for almost a decade, can find something completely new,” LaMassa said.

(Illustration by Michael S. Helfenbein)

Source: Yale university

Astronomers discover a replica solar system

This image shows Kepler-444 and its five orbiting planets. (Courtesy of Peter Devine and Tiago Campante/University of Birmingham)
Scientists have located an ancient solar system, dating back to the dawn of the galaxy, which appears to be a miniature version of the inner planets in our own solar system.

An international research group, including Yale University professors of astronomy Sarbani Basu and Debra Fischer, announced the discovery Jan. 27 in The Astrophysical Journal. The findings are the result of observations made by the NASA Kepler spacecraft over a period of four years.

The old, Sun-like star, named Kepler-444, has five orbiting planets with sizes between those of Mercury and Venus. Kepler-444 formed 11.2 billion years ago, when the universe was less than 20% of its current age. This makes Kepler-444 the oldest known system of terrestrial-sized planets. The Kepler-444 system was already older than our own solar system is today when our Sun and planets were born.

“This system shows that planet formation could take place under very different conditions from the ones in which our solar system was formed and has implications for estimating the total number of planets in our galaxy, and other galaxies,” Basu said.

The five planets in the Kepler-444 system have orbits that are equivalent to less than one-tenth of Earth’s distance from the Sun. The Kepler-444 planets are rocky and Earth-like, but their exact compositions are uncertain.

The scientists carried out their research using asteroseismology — listening to the host star’s natural resonances, which are caused by sound trapped within it. These oscillations lead to miniscule changes or pulses in the star’s brightness, allowing researchers to measure the star’s diameter, mass, and age. The planets were then detected from the dimming that occurs when the planets transited, or passed across, the stellar disc. This fractional fading in the intensity of starlight enabled scientists to measure accurately the sizes of the planets relative to the size of the star.

“There are far-reaching implications for this discovery,” said lead author Tiago Campante of the University of Birmingham (U.K.). “We now know that Earth-sized planets have formed throughout most of the universe’s 13.8-billion-year history, which could provide scope for the existence of ancient life in the galaxy.”

The research collaboration involved nearly two-dozen institutions in the United States, England, Denmark, Portugal, Australia, Germany, and Italy.

Source: Yale university

SOHO and Hinode Offer New Insight Into Solar Eruptions

Written By Unknown on Wednesday, January 28, 2015 | 6:14 PM

Scientists are trying to understand the precise details of what creates giant explosions in the sun's atmosphere, such as this solar eruption from Oct. 14, 2012, as seen by NASA's Solar Dynamic Observatory. Image Credit: NASA/SDO/Amari
The sun is home to the largest explosions in the solar system. For example, it regularly produces huge eruptions known as coronal mass ejections – when billions of tons of solar material erupt off the sun, spewing into space and racing toward the very edges of the solar system. Scientists know that these ejections, called CMEs, are caused by magnetic energy building up on the sun, which suddenly releases. But the details of what causes the build up and triggers the release are not precisely understood.

A journal paper in Nature magazine on Oct. 23, 2014, used data from NASA missions to present an example of how something called a magnetic flux rope builds up over time until it is so unstable that even the slightest perturbation will send it flying. Understanding what triggers CMEs is crucial not only for better understanding of our sun, but also to lay the groundwork for predicting when such giant explosions might happen.

"We looked at a well-studied CME from 2006," said Tahar Amari first author on the Nature paper at Ecole Polytechnique in France. "We knew that there had been a great deal of data available for this CME and much analysis already done, but no one had created a comprehensive picture of what happened."

Amari and his colleagues used a traditional meteorology technique to examine the event: Gather observations from the days before the CME to track how the event grew over time. They used observations from the European Space Agency and NASA's Solar and Heliospheric Observatory, or SOHO, and the Japanese Aerospace Exploration Agency and NASA's Hinode, as well as from the Paris-Meudon Observatory.
Scientists created this model to examine the magnetic field before a giant solar eruption – a coronal mass ejection – which occurred on Dec. 13, 2006. The orange lines show magnetic field lines. The grey line represents what's called a flux rope, which built up the day before the event. Image Credit: Amari/Ecole Poytechnique
The team wanted to see if they could distinguish between two broad theories about how the magnetic energy develops. The first model describes a situation in which a series of loops of magnetic fields on the sun – known as an arcade – is the start of every active region CME. 

This arcade has a weak point at the top, a place where the energy from below can burst through once it's great enough. During the eruption a flux rope forms, which can be seen inside the CME as it surges away from the sun.

The second model assumes that the flux rope is there before the CME erupts. In this theory, no weak point is required. Instead, the flux rope gains more and more energy, and becomes increasingly unstable until a disturbance on the sun causes it to release the energy out into space.

Amari and his team used magnetic data from the surface obtained by Hinode, but they also needed magnetic data for the sun's atmosphere, the corona, which is strongly affected by its magnetic field.

"The corona is so hot that most of the techniques to measure the magnetic field don't work," said Amari. "So we developed an efficient and accurate model to compute the magnetic field there, based on the data we had from the surface, and the equations governing the physics of the low corona above active regions."

With these two data sets in hand, the team examined what happened in the four days before the 2006 CME erupted. They could see the magnetic energy building; it was clear something was emerging. Only, however, on the last day did a flux rope develop and only then did it have enough energy built up to power a CME eruption. At this point, some small disruption was enough of a nudge to make the flux rope erupt.

A model of the eruption of a giant magnetic rope that led to a coronal mass ejection on the sun in December 2006.

A model of the eruption of a giant magnetic rope that led to a coronal mass ejection on the sun in December 2006. The model showed that magnetic fields built up for several days before the eruption.

"In this case no weak point up in the atmosphere was needed to allow the energy to be released," said Amari. "There is, instead, a kind of critical value of energy, a value we can compute based on seeing an active magnetic region on the sun. Beneath that value the magnetic field will stay quiet. Above that, it is likely to erupt. There is also a critical height for rising flux rope, beyond which the magnetic loops above can no longer keep it confined."

The team explored the initial conditions from this event and put the information into another dynamical model the team had developed. The simulation mirrored what was actually seen, with an eruption occurring only when the critical energy and height were reached on the last day.

Amari points out that just because this CME contained a flux rope prior to eruption, it doesn't mean that other CMEs can’t erupt based on other physical catalysts. But it clearly describes one mechanism that is at work on the sun.

By measuring and calculating the magnetic fields on the sun, coupled with determining how to measure the critical tipping point where a CME can erupt, the paper offers new ways to determine the possibility of eruption from any given active area on the sun.

Source: Nasa

The state of astronomy before Hubble and the difficulties of observing from the ground that drove the need for a space telescope' Videos

This video looks at the state of astronomy before Hubble and the difficulties of observing from the ground that drove the need for a space telescope. Image Credit: Space Telescope Science Institute
Dr. Nancy Grace Roman, first chief astronomer at NASA’s then Office of Space Science and the one who set up NASA’s astronomy program in the 1960s, speaks about the importance of building and launching a space telescope instead of building duplicates of the Earth-based Palomar 200-inch telescope.

"Astronomers have wanted for generations actually to get a telescope above the atmosphere,” Roman said. “I like to describe the atmosphere being something like looking through an old stained glass window… The glass has defects in it and that sort of keeps you from getting a sharp picture and the atmosphere also has defects." 

"The very sharp images it would produce would allow you to see things that were much fainter than would ever be possible from the ground," said C. Robert O'Dell, of Vanderbilt University in Nashville, Tennessee. O'Dell leads a research team that used Hubble and several ground-based telescopes to obtain the best view yet of the iconic Ring Nebula.
The video addresses several challenges at the time of Hubble's creation, including digital imaging at a time when the industry was in its infancy. The video also speaks on how the telescope has far exceeded its initial life-span.

The 4 minute and 23 second video was produced by STScI. The "Hubble 25th Anniversary" video series is available in HQ, large and small Quicktime formats, HD, large and small WMV formats, and HD, large and small Xvid formats.

WATCH VIDEO HERE



Source: Nasa Hubble

Ballooning Offers a Multi-Disciplinary Platform for Performing Research in a Space-Like Environment

A view from the edge of space, the High Energy Replicated Optics to Explore the Sun (HEROES) telescope is a hard X-ray telescope, sensitive in the 20-75 keV range and designed to fly on a high-altitude balloon platform. The HEROES telescope is one example of a balloon payload designed to fly at this altitude. This payload launched from Fort Sumner, NM, in the Fall of 2013, and the flight lasted for 27 hours. At its maximum altitude of just over 39 km, the telescope pointed at the Sun, the black hole candidate GRS 1915+105, and the Crab Nebula, with the capability to carry out high resolution imaging and spectroscopy. The HEROES Project is a collaboration between NASA Marshall Space Flight Center and Goddard Space Flight Center and was funded through the NASA Hands On Project Experience Training Opportunity. (Photo Credit: R. Salter, Columbia Scientific Balloon Facility)
New discoveries are being made on an annual basis by researchers flying their instruments on a high-altitude balloon platform. Ease of access to ballooning, relatively low cost and the potential for quick turn-around response times create a large appeal for using this platform to perform novel science and to train new scientists. This appeal is reinforced by the availability of a range of balloon sizes to accommodate various payload types, multiple launch sites (for shorter and longer duration flights), and more sophisticated gondolas.

Since the 1950s, and the invention of the 'natural' shaped polyethylene balloon, there has been a surge in the quality and amount of science being performed on this platform. The flexibility, reliability and relatively low-cost of the high-altitude balloon platform, over that of a satellite, makes for an attractive means of carrying out novel science in a space-like environment across multiple disciplines, which include: high-energy astrophysics (particle, x-ray and gamma-ray), IR/sub-mm (CMB to planetary), heliophysics, geospace and atmospheric research.

Existing balloons are capable of carrying large payloads to high altitudes for flight durations lasting tens of days. The longest flight to date was that of SuperTIGER in 2012-2013 on a vented zero-pressure balloon. This payload weighed 2,025 kg (not including flight straps) and flew to a maximum altitude of ~39.6 km. The entire flight lasted for just over 55 days. The development of the Super-Pressure Balloon holds promise for achieving even longer flights launching from Antarctica (> 100 days), and Long Duration Balloon flights from mid-latitude launch sites. This capability, combined with improved payload pointing, light-weight gondolas and more sophisticated instrumentation will enable scientists to make new discoveries and develop novel instrumentation suitable for orbital missions. This platform will also continue to provide a training ground for the next generation of scientists and engineers.

Additional co-authors include I. Steve Smith from the Space Science and Engineering Division at Southwest Research Institute, and W. Vernon Jones from the Science Mission Directorate, Astrophysics Division at NASA Headquarters. The corresponding author for this study is Jessica A. Gaskin, Jessica.Gaskin@nasa.gov.

Source: WS

Tail discovered on long-known asteroids

Written By Unknown on Monday, January 26, 2015 | 7:48 PM

The faint tail can be seen in active asteroid 62412. Image courtesy of Scott Sheppard
Washington, D.C.--A two-person team of Carnegie's Scott Sheppard and Chadwick Trujillo of the Gemini Observatory has discovered a new active asteroid, called 62412, in the Solar System's main asteroid belt between Mars and Jupiter. It is the first comet-like object seen in the Hygiea family of asteroids. Sheppard will present his team's findings at the American Astronomical Society's Division of Planetary Sciences meeting and participate today in a press conference organized by the society.

Active asteroids are a newly recognized phenomenon. 62412 is only the 13th known active asteroid in the main asteroid belt. Sheppard and Trujillo estimate that there are likely about 100 of them in the main asteroid belt, based on their discovery.

Active asteroids have stable orbits between Mars and Jupiter like other asteroids. However, unlike other asteroids, they sometimes have the appearance of comets, when dust or gas is ejected from their surfaces to create a sporadic tail effect. Sheppard and Trujillo discovered an unexpected tail on 62412, an object which had been known as a typical asteroid for over a decade. Their findings reclassify it as an active asteroid. The reasons for this loss of material and subsequent tail in active asteroids are unknown, although there are several theories such as recent impacts or sublimation from solid to gas of exposed ices.

"Until about ten years ago, it was pretty obvious what a comet was and what a comet wasn't, but that is all changing as we realize that not all of these objects show activity all of the time," Sheppard said.

In the past, asteroids were thought to be mostly unchanging objects, but an improved ability to observe them has allowed scientists to discover tails and comas, which are the thin envelope of an atmosphere that surrounds a comet's nucleus.

"We're actually looking anew through our deep survey at a population of objects that other people cannot easily observe, because we're going much deeper," Sheppard said, explaining why they were able to see that 62412 was active when it had been considered a typical main belt asteroid for 15 years.;

Discoveries such as this one can help researchers determine the processes that cause some asteroids to become active. Sheppard will discuss his and Trujillo's theories about the genesis of 62412's activity. They found that 62412 has a very fast rotation that likely shifts material around its surface, some of which may be emitted to form the comet-like appearance. The tail may be created directly from ejected material off the fast rotating nucleus, or from ice within the asteroid subliming into water vapor after being freshly exposed on the surface. They also find a density for 62412 typical of primitive asteroids and not consistent with the much lower-density comets. Further monitoring of this unusual object will help confirm the activity's source.

Sheppard and Trujillo have a paper about this work in press at The Astronomical Journal.


Source: NASA

The Cosmic radio burst caught red-handed

A schematic illustration of CSIRO’s Parkes radio telescope receiving the polarised signal from the new ‘fast radio burst’. Credit: Swinburne Astronomy Productions.
Pasadena, CA— Fast radio bursts are quick, bright flashes of radio waves from an unknown source in space. They are a mysterious phenomenon that last only a few milliseconds, and until now they have not been observed in real time. An international team of astronomers, including three from the Carnegie Observatories, has for the first time observed a fast radio burst happening live. Their work is published in Monthly Notices of the Royal Astronomical Society.

There is a great deal of scientific interest in fast radio bursts, particularly in uncovering their origin.

“These events are one of the biggest mysteries in the Universe” noted Carnegie Observatories' Acting Director John Mulchaey. “Until now, astronomers were not able to catch one of these events in the act.”

Only seven fast radio bursts have previously been discovered, since the first one found in 2007. All were found retroactively by combing through data from the Parkes radio telescope in eastern Australia and the Arecibo telescope in Puerto Rico.

“These bursts were generally discovered weeks or months or even more than a decade after they happened! We’re the first to catch one in real time,” said Emily Petroff, a PhD candidate from Swinburne University of Technology in Melbourne, Australia and lead author of the publication.
Swinburne is a member institution of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO).

In order to observe the fast radio burst in real time, the team mobilized 12 telescopes around the world and in space, including Carnegie’s Magellan and Swope telescopes. Each telescope followed-up on the original burst observation at different wavelengths.

Measurements of the interaction between previously detected fast radio burst’s flashes and the free electrons their signals encountered in space as they traveled to reach us had previously indicated that the bursts likely originated far outside of our galaxy. But the idea was controversial.

The team’s data indicates that the burst originated up to 5.5 billion light years away. This means that the sources of theses bursts are extremely bright and could perhaps be used as a cosmological tool for measuring and understanding our universe once we come to understand them better.

“Together, our observations allowed the team to rule out some of the previously proposed sources for the bursts, including nearby supernovae,” explained Carnegie’s Mansi Kasliwal who was on the team along with Mulchaey and colleague Yue Shen. “Short gamma-ray bursts are still a possibility, as are distant magnetic neutron stars called magnetars, but not long gamma ray bursts.”

Gamma ray bursts are high-energy explosions that form some of the brightest celestial events. Long bursts can signify energy released during a supernova and are followed by an afterglow, which emits lower wavelength radiation than the original explosion.

Another interesting piece of information the team was able to gather about the burst is its polarization. The orientation of the radio waves indicates that the burst likely originated near or passed through a magnetic field, information that can help narrow down potential sources going forward.

“As we continue to search for the source of fast radio bursts, Carnegie is well positioned to make big strides in the field,” Mulchaey said. “Quick access to big telescopes like Magellan may be the key to solving this mystery.”

Caption: A schematic illustration of CSIRO’s Parkes radio telescope receiving the polarised signal from the new fast radio burst. Image is credited to Swinburne Astronomy Productions.

Other co-authors are: M. Bailes (Swinburne University of Technology and ARC Centre of Excellence for All-sky Astrophysics); E.D. Barr (Swinburne University of Technology and ARC Centre of Excellence for All-sky Astrophysics); B. R. Barsdell (Harvard-Smithsonian Center for Astrophysics); N. D. R. Bhat (ARC Centre of Excellence for All-sky Astrophysics and Curtin University) ; F. Bian (Australian National University); S. Burke-Spolaor (Caltech); M. Caleb(Australian National University, Swinburne University of Technology, ARC Centre of Excellence for All-sky Astrophysics); D. Champion (Max Planck Institut für Radioastronomie); P. Chandra (Tata Institute of Fundamental Research Pune University Campus); G. Da Costa (Australian National University); C. Delvaux (Max-Planck-Institut für extraterrestrische Physik); C. Flynn (Swinburne University of Technology and ARC Centre of Excellence for All-sky Astrophysics); N. Gehrels (NASA Goddard Space Flight Center); J. Greiner (Max-Planck-Institut für extraterrestrische Physik); A. Jameson (Swinburne University of Technology and ARC Centre of Excellence for All-sky Astrophysics); S. Johnston (CSIRO Astronomy & Space Science Australia Telescope National Facility); E. F. Keane (Swinburne University of Technology and ARC Centre of Excellence for All-sky Astrophysics); S. Keller (Australian National University); J. Kocz (Harvard-Smithsonian Center for Astrophysics and Jet Propulsion Laboratory, Caltech); M. Kramer (Max Planck Institut für Radioastronomie and University of Manchester) G. Leloudas (University of Copenhagen and Weizmann Institute of Science); D. Malesani (University of Copenhagen); C. Ng (Max Planck Institut für Radioastronomie); E. O. Ofek (Weizmann Institute of Science); D. A. Perley (Caltech); A. Possenti (Osservatorio Astronomico di Cagliari); B. P. Schmidt (Australian National University and ARC Centre of Excellence for All-sky Astrophysics); B. Stappers (University of Manchester); P. Tisserand (Australian National University and ARC Centre of Excellence for All-sky Astrophysics); W. van Straten (Swinburne University of Technology and ARC Centre of Excellence for All-sky Astrophysics ); and C. Wolf (Australian National University and ARC Centre of Excellence for All-sky Astrophysics).

The Parkes radio telescope and the Australia Telescope Compact Array are part of the Australia Telescope National Facility, which is funded by the Commonwealth of Australia for operation as a National Facility and managed by CSIRO. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO). GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. Research with the ANU SkyMapper telescope is supported in part through an ARC Discovery Grant. Part of the funding for GROND was granted from a Leibniz-Prize. The Dark Cosmology Centre is supported by the Danish National Research council. Other support came from Curtin Research Fellowship;, EXTraS, funded from the European Union's Seventh Framework Programme for research, technological development and demonstration; Hubble Fellowships; a Carnegie-Princeton Fellowship; the Arye Dissentshik career development; the Willner Family Leadership Institute Ilan Gluzman (Secaucus, N.J.), the Israeli Ministry of Science; Israel Science Foundation; Minerv;, Weizmann-UK; the I-CORE Program of the Planning and Budgeting Committee.

The Carnegie Institution for Science (carnegiescience.edu) is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

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Source: Royal Astronomical Society

Exploding stars prove Newton's law of gravity unchanged over cosmic time

Written By Unknown on Wednesday, January 14, 2015 | 8:56 PM

Remains of a Type Ia supernovae (G299.2-2.9). Credit: X-ray: NASA/CXC/U.Texas/S. Park et al, ROSAT; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF
Australian astronomers have combined all observations of supernovae ever made to determine that the strength of gravity has remained unchanged over the last nine billion years.

Newton's gravitational constant, known as G, describes the attractive force between two objects, together with the separation between them and their masses. It has been previously suggested that G could have been slowly changing over the 13.8 billion years since the Big Bang.

If G has been decreasing over time, for example, this would mean that Earth's distance to the Sun was slightly larger in the past, meaning that we would experience longer seasons now compared to much earlier points in Earth's history.

But researchers at Swinburne University of Technology in Melbourne have now analysed the light given off by 580 supernova explosions in the nearby and far Universe and have shown that the strength of gravity has not changed.

"Looking back in cosmic time to find out how the laws of physics may have changed is not new" Swinburne Professor Jeremy Mould said. "But supernova cosmology now allows us to do this with gravity."

A Type 1a supernova marks the violent death of a star called a white dwarf, which is as massive as our Sun but packed into a ball the size of our Earth.

Our telescopes can detect the light from this explosion and use its brightness as a 'standard candle' to measure distances in the Universe, a tool that helped Australian astronomer Professor Brian Schmidt in his 2011 Nobel Prize winning work, discovering the mysterious force Dark Energy.

Professor Mould and his PhD student Syed Uddin at the Swinburne Centre for Astrophysics and Supercomputing and the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) assumed that these supernova explosions happen when a white dwarf reaches a critical mass or after colliding with other stars to 'tip it over the edge'.

"This critical mass depends on Newton's gravitational constant G and allows us to monitor it over billions of years of cosmic time -- instead of only decades, as was the case in previous studies," Professor Mould said.

Despite these vastly different time spans, their results agree with findings from the Lunar Laser Ranging Experiment that has been measuring the distance between Earth and the Moon since NASA's Apollo missions in the 1960s and has been able to monitor possible variations in G at very high precision.

"Our cosmological analysis complements experimental efforts to describe and constrain the laws of physics in a new way and over cosmic time." Mr Uddin said.

In their current publication, the Swinburne researchers were able to set an upper limit on the change in Newton's gravitational constant of 1 part in 10 billion per year over the past nine billion years.

The ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) is a collaboration between The Australian National University, The University of Sydney, The University of Melbourne, Swinburne University of Technology, the University of Queensland, The University of Western Australia and Curtin University, the latter two participating together as the International Centre for Radio Astronomy Research. CAASTRO is funded under the Australian Research Council Centre of Excellence program, with additional funding from the seven participating universities and from the NSW State Government's Science Leveraging Fund.

The research is published this month in the Publications of the Astronomical Society of Australia.

Source: Swinburne University of Technology

Plugging the hole in Hawking's black hole theory

Recently physicists have been poking holes again in Stephen Hawking's black hole theory -- including Hawking himself. For decades physicists across the globe have been trying to figure out the mysteries of black holes -- those fascinating monstrous entities that have such intense gravitational pull that nothing -- not even light -- can escape from them. Credit: Still image from video courtesy of Michigan State University
Recently physicists have been poking holes again in Stephen Hawking's black hole theory -- including Hawking himself. For decades physicists across the globe have been trying to figure out the mysteries of black holes -- those fascinating monstrous entities that have such intense gravitational pull that nothing -- not even light -- can escape from them. Now Professor Chris Adami, Michigan State University, has jumped into the fray.

The debate about the behavior of black holes, which has been ongoing since 1975, was reignited when Hawking posted a blog on Jan. 22, 2014, stating that event horizons -- the invisible boundaries of black holes -- do not exist.

Hawking, considered to be the foremost expert on black holes, has over the years revised his theory and continues to work on understanding these cosmic puzzles.

One of the many perplexities is a decades-old debate about what happens to information -- matter or energy and their characteristics at the atomic and subatomic level -- in black holes.

"In 1975, Hawking discovered that black holes aren't all black. They actually radiate a featureless glow, now called Hawking radiation," Adami said. "In his original theory, 
Hawking stated that the radiation slowly consumes the black hole and it eventually evaporates and disappears, concluding that information and anything that enters the black hole would be irretrievably lost."

But this theory created a fundamental problem, dubbed the information paradox.
Now Adami believes he's solved it.

"According to the laws of quantum physics, information can't disappear," Adami said. "A loss of information would imply that the universe itself would suddenly become unpredictable every time the black hole swallows a particle. That is just inconceivable. No law of physics that we know allows this to happen."

So if the black hole sucks in information with its intense gravitational pull, then later disappears entirely, information and all, how can the laws of quantum physics be preserved?
The solution, Adami says, is that the information is contained in the stimulated emission of radiation, which must accompany the Hawking radiation -- the glow that makes a black hole not so black. Stimulated emission makes the black hole glow in the information that it swallowed.

"Stimulated emission is the physical process behind LASERS (Light Amplification by Stimulated Emission of Radiation). Basically, it works like a copy machine: you throw something into the machine, and two identical somethings come out.

"If you throw information at a black hole, just before it is swallowed, the black hole first makes a copy that is left outside. This copying mechanism was discovered by Albert Einstein in 1917, and without it, physics cannot be consistent," Adami said.

Do others agree with Adami's theory that stimulated emission is the missing piece that solves the information paradox?

According to Paul Davies, cosmologist, astrobiologist and theoretical physicist at Arizona State University, "In my view Chris Adami has correctly identified the solution to the so-called black hole information paradox. Ironically, it has been hiding in plain sight for years. Hawking's famous black hole radiation is an example of so-called spontaneous emission of radiation, but it is only part of the story. There must also be the possibility of stimulated emission -- the process that puts the S in LASER."

With so many researchers trying to fix Hawking's theory, why did it take so long if it was hiding in plain sight?

"While a few people did realize that the stimulated emission effect was missing in Hawking's calculation, they could not resolve the paradox without a deep understanding of quantum communication theory," Adami said. Quantum communication theory was designed to understand how information interacts with quantum systems, and Adami was one of the pioneers of quantum information theory back in the '90s.

Trying to solve this information paradox has kept Adami awake many nights as demonstrated by his thick notebooks filled with 10 years of mathematical calculations.
So where does this leave us, according to Adami?

"Stephen Hawking's wonderful theory is now complete in my opinion. The hole in the black hole theory is plugged, and I can now sleep at night," he said.

Adami may now sleep well at night, but his theory is sure to keep other physicists up trying to confirm whether he has actually solved the mystery.

The study was co-authored by Greg Ver Steeg, University of Southern California and is published online in the journal Classical and Quantum Gravity.

 
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