2013년 4월 24일 수요일

Europe Gets Serious About Space Junk Menace

Hundreds of scientists, engineers and space-law experts are gathering this week to discuss the growing problem of space debris, and will propose ways to curb the accumulation of new junk in orbit.
The 6th European Conference on Space Debris is being held April 22-25 at the European Space Operations Center in Darmstadt, Germany. More than 300 representatives, ranging from researchers to policymakers, are expected to attend the four-day event, according to officials at the European Space Agency (ESA).
Conference attendees will discuss the buildup of potentially harmful debris in orbit, and address possible ways to remove defunct satellites and other pieces of errant space hardware.
More than 170 million pieces of space junk are currently orbiting Earth, including 29,000 objects that are larger than 4 inches (10 centimeters), according to ESA estimates. As they speed through space at 17,000 mph (27,000 km/h), these objects pose collision risks to both other satellites in orbit and the International Space Station.
"Any of these objects can harm an operational spacecraft," Heiner Klinkrad, head of ESA's Space Debris Office, said in a statement.
Roughly two-thirds of the known pieces of debris were created by explosions in orbit or collisions, ESA officials said.
In 2009, a U.S. Iridium communications satellite was struck by a defunct Russian Cosmos military satellite in what became a wake-up call for the industry. The crash destroyed the two spacecraft and left a huge cloud of debris.
Then, in 2007, China intentionally destroyed one of its aging weather satellites in a controversial anti-satellite test that littered Earth’s orbit with more than 2,500 scraps of space junk.
Since then, researchers and satellite operators have tried to tackle the issue of sustainability in space.
"Space-debris mitigation measures, if properly implemented by satellite designers and mission operators, can curtail the growth rate of the debris population," Klinkrad said. "Active debris removal, however, has been shown to be necessary to reverse the debris increase."
But finding any solution to the space-debris problem will require a collaborative approach.
"As this is a global task, active removal is a challenge that should be undertaken by joint efforts in cooperation with the world's space agencies and industry," Thomas Reiter, ESA's director of human spaceflight and operations, said in a statement.

Source of Article : space.com

Hubble Telescope Photographs Potential 'Comet of the Century'

NASA's iconic Hubble Space Telescope has snapped stunning new photos of Comet ISON, which could become one of the brightest comets ever seen when it zips through the inner solar system this fall.
Hubble captured the new photos on April 10, when Comet ISON was slightly closer than Jupiter. At the time the icy wanderer was about 386 million miles (621 million kilometers) from the sun and 394 million miles (634 million km) from Earth.
The new images are already helping astronomers take a bead on the mysterious Comet ISON, which may shine as brightly as the full moon when it makes its closest pass by the sun in late November. (The comet poses no threat to Earth, NASA has said.) 
For example, the Hubble telescope photos show that ISON is already becoming quite active, though it's still pretty far from our star. The comet's dusty head, or coma, is about 3,100 miles (5,000 km) wide, and its tail is more than 57,000 miles (92,000 km) long, astronomers said. And ISON sports a dust-blasting jet that extends at least 2,300 miles (3,700 km).
Yet the comet's nucleus is surprisingly small — no more than 3 or 4 miles (4.8 to 6.5 km) across.
This small core makes the comet's behavior on its trip around the sun, which will bring ISON within 730,000 miles (nearly 1.2 million km) of the solar surface on Nov. 28, especially tough to predict, researchers said. Also complicating the forecast is the fact that ISON is apparently making its first trip through the inner solar system from the distant, icy Oort cloud.
So it's difficult to know if ISON will live up to its billing or fizzle out like Comet Kohoutek — another possible "comet of the century" — did in 1973.
But Comet ISON's relatively pristine state has a real upside to astronomers, who will study the material that sublimates off the comet to gain insight into its composition.
"As a first-time visitor to the inner solar system, Comet C/ISON provides astronomers a rare opportunity to study a fresh comet preserved since the formation of the solar system," Jian-Yang Li of the Planetary Science Institute in Tucson, Ariz., who led a team that imaged the comet, said in a statement. "The expected high brightness of the comet as it nears the sun allows for many important measurements that are impossible for most other fresh comets."
NASA has organized a Comet ISON Observing Campaign to coordinate the efforts of observatories on the ground and in space. Hubble is seen as a key player in this campaign, along with a number of other instruments.
Comet ISON is officially designated as C/2012 S1 (ISON) and was discovered in September 2012 by Russian amateur astronomers Vitali Nevski and Artyom Novichonok.
Hubble's new ISON photos were taken just two weeks before the telescope's 23rd anniversary. The Hubble Space Telescope, a collaboration between NASA and the European Space Agency, launched aboard the space shuttle Discovery on April 24, 1990.

Source of Article : space.com

Cosmonauts May Carry Olympic Torch and 'Flame' on Spacewalk

Russia may shift its rocket launch and spacewalk schedule to send the torch — and maybe even the flame — for next year's Olympics to the International Space Station (ISS), according to Russia's federal space agency and local media reports.
Set to host the 2014 Winter Games in Sochi on the Black Sea coast, Russia plans to launch the traditional Olympic torch relay later this year on Oct. 7. As the flame passes between runners in 2,900 towns and cities spread across the country, a replica of the torch and perhaps an imitation of its flame will lift off on a Soyuz spacecraft with the next crew members for the space station.
"No decision has been made so far whether an imitation of the Olympic flame or a torch without fire would be moved into outer space," a source in Russia's rocket industry told the Interfax-AVN news service. "No member of the state commission will assume responsibility for moving an open flame close to the Soyuz spacecraft or the ISS." 
Flame or no flame, Russia's space agency Roscosmos is planning to do more than deliver the torch to the orbiting outpost, a feat that has been achieved before. The idea is to have cosmonauts carry the torch outside the station on a spacewalk prior to it returning to Earth.
According to the Interfax report, the Olympic torch will be "moved into open space" by cosmonauts Oleg Kotov and Sergei Ryazansky, who will arrive at the space station in late September.
To choreograph the orbital torch relay, Roscosmos and its International Space Station partners, including NASA, will need to agree on adjustments to the schedule of launches and spacewalks.
To deliver the lit or unlit torch to the space complex, the planned Nov. 25 liftoff of Soyuz TMA-11M would need to launch almost three weeks earlier on Nov. 7. Roscosmos cosmonaut Mikhail Tyurin, NASA's Rick Mastracchio and Japanese astronaut Koichi Wakata would fly to the space station with the torch.
The spacewalk, which would include other, more routine maintenance tasks for the two cosmonauts to complete in addition to carrying the torch, would then take place during the brief time between the arrival of Soyuz TMA-11M and the departure of Soyuz TMA-09M.
Under the proposed plan, Roscosmos cosmonaut Fyodor Yurchikhin, NASA astronaut Karen Nyberg and European Space Agency (ESA) astronaut Luca Parmitano will stay in space at least a day longer than originally scheduled to return to Earth with the torch on Nov. 11.
The torch's handoff between crews would also result in a short period when nine people would be aboard the space station, a departure from what has in recent years become the norm for crew changes, when the prior crew of three would leave before the next crew arrives.
One of the key symbols of the Games, the torch for the 2014 Sochi Olympics was designed by a team of famous Russian designers and engineers. The aluminum and red torch — red being the traditional color of Russian sports — was crafted to evoke the feathers of a Phoenix, which folklore says brings good fortune and happiness.
How the torches on the ground — there are 14,000 being produced — will differ from the one launching into space, and how the flame will be simulated or safely achieved in orbit, if it is flown, has yet to be released.
If approved, the torch's trip will mark the second time the Olympic torch has arrived aboard the International Space Station. In May 2000, the space shuttle Atlantis launched the STS-101 mission to the orbiting outpost with a replica of the Sydney Summer Olympics torch.
Four years earlier on shuttle Columbia's STS-78 mission, the crew carried an unlit torch into orbit and then took part in the ground-based torch relay soon after landing back on Earth.
The Olympic flame, without the torch, also made its way through space in the form of an electric signal. As part of the 1976 relay, the flame was sent from Greece to Ottawa via satellite. Heat sensors in Greece detected the flame, the signal was transmitted overseas and a laser beam lit the torch.

Source of Article : space.com

Hubble Telescope Looks to the Future After 23 Years in Space

NASA's Hubble Space Telescope celebrates a whopping 23 years in orbit today, but astronomers are hopeful that the iconic instrument can keep studying the heavens for years to come.
The Hubble team is aiming to keep the telescope — which launched aboard the space shuttle Discovery on April 24, 1990 — operating through 2020. That would ensure at least one year of overlap with its $8.8 billion successor, the James Webb Space Telescope (JWST), which is slated to launch in late 2018.
"At this point in time, that appears to be feasible," said Hubble Mission Office head Ken Sembach of the Space Telescope Science Institute (STScI) in Baltimore, Md., which manages Hubble's science operations.
"It may not be operating quite as well as it's operating today, because it will degrade with time, obviously," Sembach told SPACE.com. "But that's our hope, and that's our plan, and we expect that that should actually be possible."
A bumpy start
Though the Hubble Space Telescope is known today for its gorgeous cosmic images and contributions to astronomy — its observations revealed, for example, that the expansion of the universe is accelerating, leading astronomers to propose the existence of a mysterious force called dark energy — the telescope's mission had a decidedly bumpy start.
Hubble launched with a primary mirror that was ground to the wrong prescription, and many of the images it captured in its first three years were thus frustratingly fuzzy.
"Hubble was the butt of a lot of jokes — satirizing cartoons, in newspapers and on late-night talk shows," Sembach said. "The poor observatory was kind of a laughingstock there in the beginning."
But Hubble was designed to be serviced by spacewalking astronauts, and the problem was solved with the installation of corrective optics in December 1993. Astronauts repaired and upgraded Hubble four more times over the years, once each in 1997, 1999, 2002 and 2009.
This on-orbit attention played a major role in extending Hubble's surprising scientific lifetime, Sembach said.
"I don't think when Hubble was first envisioned that anybody expected it to last more than five or 10 years, let alone 20 years," he said. "I think that the repairs and everything else that has been done to the observatory have been far more spectacular than had ever been envisioned originally."

Teaming up with JWST
NASA has committed to funding Hubble through April 30, 2016. But support for the telescope — whose annual operating costs total about $98 million — should continue beyond that, Sembach said, provided Hubble keeps returning good data.
"As long as the observatory remains scientifically productive, I think that the country will still be willing to support the great science that it's producing," he said. "If it gets to the point that the science isn't compelling anymore, then that will be the time to turn it off."
There will be no more servicing missions now that NASA's space shuttle fleet is retired, so the telescope is on its own. If Hubble does manage to hang on through 2020, it and JWST will make a powerful observing team, Sembach added, with Hubble's sharp vision in optical and ultraviolet wavelengths complementing the infared-optimized JWST well. 
"There's going to be all kinds of discoveries coming from JWST in its first year or two of observations," Sembach said. "There are going to be many things that you'd like to have exquisite optical images of that JWST's looking at in the infrared."
Such observations could not always be made by the two telescopes sequentially. They'd both have to be operating simultaneously, for example, to study one-off cosmic events like supernova explosions or the spectacular 1994 crash of comet Shoemaker-Levy 9 into Jupiter, said STScI astronomer Mario Livio.
"Things that are time-critical — there is no other way of doing it, other than the two telescopes overlapping," Livio told SPACE.com.
Looking ahead, and looking back
Astronomers have used Hubble, which is a joint effort involving NASA and the European Space Agency,  to investigate a variety of cosmic phenomena and objects over its first 23 years, and the telescope's workload will be similarly diverse in the future. But Sembach mentioned a few areas that should receive particular attention in the coming years.
One is exoplanet research. Hubble was the first instrument to obtain the spectrum of an alien planet's atmosphere, Sembach said, and scientists are eager to do more such work as the tally of known worlds beyond our solar system continues to grow.
Hubble will also devote considerable observing time over the next three years to a project called Hubble's Frontier Fields, which should reveal the most distant objects known in the universe, Sembach said.
Frontier Fields follows in the footsteps of three other Hubble efforts that spotted extremely far-flung cosmic objects — the groundbreaking Deep Field photo in 1996, 2004's Ultra Deep Field and the eXtreme Deep Field in 2012.
Such work will add to Hubble's legacy, which Sembach said is already impressive on the scientific and popular-culture fronts.
"For astronomers, Hubble is the go-to observatory. If you have something that you really need to understand — you really want to know about it in detail — the observatory of choice is almost always Hubble," Sembach said, noting that the telescope has made more than 1 million science observations, which have led to the publication of more than 11,000 scientific papers.
"And from the American public's standpoint, I think it's really hard to underestimate the impact that Hubble's had. There are Hubble pictures on classroom walls in just about every school in the country. You see Hubble imagery on television shows, you see it in books, you see it in art," he added. "I think it's become part of the culture."
Livio echoed those sentiments.
"Ask any person on the street the name of one telescope, and they'll say Hubble," he said. "So that just shows you the level of impact."

Source of Article : space.com

Rare Meteorite Grains May be from Supernova That Sparked Solar System

Two surprising grains of sand in a pair of meteorites that landed on Earth suggest they were formed in a single supernova that occurred billions of years ago, new research suggests. These grains may even come from the same star explosion that sparked the formation of the solar system, scientists say.
Both meteorites were found in Antarctica, and appear to date from before the solar system was born 4.6 billion years ago. Each contains a single grain of silica (SiO2, which is the main ingredient of sand). The chemical signature of these grains is identical, and extremely rare — so rare, in fact, that scientists suspect both grains came from a single supernova. This type of supernova occurs when a massive star runs out of fuel for nuclear fusion and collapses in on itself in a giant explosion.
These are the first such grains found in primitive meteorites, and are distinct because of the type of oxygen contained in the silica. Previous research has uncovered a handful of space rocks containing silica grains enriched in oxygen-17, which is thought to be created by living stars. But a slightly heavier version of oxygen, called oxygen-18, was found in these two new grains. Oxygen-18 must be formed in a supernova.
The silica grains are so small they are invisible to the naked eye. Using an instrument called a NanoSIMS 50 ion microprobe, which magnifies objects 20,000 times, graduate student Pierre Haenecour of Washington University in St. Louis uncovered the single grain in one of the meteorites. The other was found by Xuchao Zhao, now a scientist at the Institute of Geology and Geophysics in Beijing, China, inside a meteorite discovered by the Chinese Antarctic Research Expedition.
Haenecour investigated just how the silica grains might have come to be, and found that their formation would have required a complex process of mixing material from various different layers of the star as it exploded.
Because the precise mixing required to create oxygen-18 is so specific, the researchers suspect that both silica grains originated in the same supernova. That supernova might even be the same explosion that gave rise to the solar system, the researchers speculated. Scientists think a shock wave from a supernova might have been the event that caused a rotating cloud of gas and dust to condense, eventually giving rise to the planets of our solar system.
As it exploded, the supernova also would have seeded the cloud with material, and some of that material may have ended up in the meteorites we find today.

Source of Article : space.com

2013년 4월 22일 월요일

Want to Live on Mars? Private Martian Colony Project Seeks Astronauts

If a one-way trip to Mars appeals to you, now's the time to apply to be part of the first crew of a Red Planet colony.
The Netherlands-based nonprofit Mars One is planning to fly teams of four astronauts to the Red Planet, with the first landing slated to occur in 2023, exactly 10 years from today (April 22), to establish a human settlement on our planetary neighbor. Today, the organization opened up its astronaut selection process, which it hopes will raise some of the funding for the project.
Those over age 18 interested in spending the rest of their lives in space can apply by submitting applicaions and short videos to the Mars One site. There is no maximum age for applicants, nor a required technical background or even nationality or language — astronaut candidates will have a few years to learn English if they don't speak it already.
Successful applicants will have intelligence, resourcefulness, courage, determination and skill, as well as psychological stability, said Mars One ambassador Gerard 't Hooft, a Nobel Prize-winning theoretical physicist.
"Selecting these people will be a very difficult task," 't Hooft said during a press conference here to announce the selection process. "There shall be no exclusion on the basis of race, nationality, religion and gender."
There will be a minor fee associated with submitting an application, which will range from $5 to $75 depending on the gross national income of the applicant's home country, officials said. The application fee for United States citizens is $38.
Mars One estimates it will need about $6 billion to send the first four inhabitants to start the Red Planet colony, with $4 billion needed to launch each subsequent crew. In addition to the application fees, the organization hopes to raise money via a reality television show that will follow its astronaut selection and training process.
Though a one-way ticket to Mars isn't everyone's idea of a dream getaway, the project's leaders anticipate a high level of enthusiasm for the mission; they've received about 10,000 emails already from people interested in applying. Mars One hopes to recruit astronauts from around the world to create a colony populated by a diverse representation of Earth's inhabitants.
"We want this to be a mission of humanity," Mars One co-founder and chief executive officer Bas Lansdorp told SPACE.com.
Mars One plans to put its astronaut finalists through seven years of training and testing exercises that will expose them to potential situations they might face during the mission. The astronaut trainees will also have to spend some time living in mock Mars colonies on Earth and communicating with Mission Control via a 6 to 20-minute time delay to simulate the lag between a signal being sent and its arrival on Mars.
By July 2015, Mars One plans to have selected its top 24 astronauts, grouped into crews of six.
So far, no spacecraft or rocket has been chosen for the journey, though organization officials say they are considering modifying the Dragon capsule being developed by the private aerospace firm SpaceX (Space Exploration Technologies Corp.). The Mars lander, rovers and habitat modules required will likely have to be designed and built from the ground up, but will be based on existing technology.
"This will not be easy," Lansdorp said. "There is a lot of engineering and testing to be done before the first humans will land. But no new inventions are needed to land humans on Mars. There might be delays, there might be cost overruns, there might even be failures, but it can be done."
The endeavor will begin with an initial test launch to Mars in 2016 to demonstrate the landing technology, with a second mission in 2018 to deliver a robotic rover to scout out landing sites. In 2020 a second rover will launch to Mars to begin assembling some of the first settlers' equipment and habitats, which will be ready and waiting when they land. The trip to Mars will take about seven months.
Mars One has hired the research firm Paragon Space Development Corporation to design the life support technologies
 needed for the mission.
"There's no doubt that the success of this mission depends on the life support system on the surface of Mars working forever," said Grant Anderson, Paragon chief engineer and co-founder. "To be successful, we have to execute a major and logical problem of applied engineering. We have to do the design, build and then test extensively before we leave."

Source of Article : space.com

Search for Northern Lights on Saturn Takes Off

Astronomers using an observatory in Hawaii kicked off a month-long campaign to study the northern lights on Saturn study Sunday (April 21) in a live webcast from Hawaii's iconic Keck Observatory.
During a three-hour webcast, scientists discussed everything from the ringed planet's atmosphere to new discoveries made about the gas giant in the last year. While speaking with the public via social media, the researchers also used the Keck Observatory to observe auroras on Saturn to understand how the mysterious phenomenon works. The scientists weren't able to show live-video of the observations, but they did review some major Saturn discoveries during the webcast.
"Up until now, it's like we have been looking at the aurora in black and white — and now we're trying to look in color," Tom Stallard, an astronomer at the University of Leicester who participated in the observations yesterday, said in a statement. "We're hoping to get much more depth to the observations we have taken — filling in a far more complete picture of the aurora as a whole, rather than disconnected parts."
The month-long campaign organized by astronomers from the University of Leicester in the U.K. brings together an international group of observers using the Cassini spacecraft in orbit around Saturn, the Hubble space telescope and the European Southern Observatory's Very Large Telescope in Chile. Over the course of the next month, scientists will take observations of the ringed beauty to understand its northern lights.
Yesterday, scientists were following up on their surprising finding that Saturn's rings cause it to "rain" on the planet. This "ring rain" on Saturn changes the molecular composition of the planet's atmosphere, potentially creating its distinctive dark and light bands on the planet's face, author of the study James O'Donoghue said.
The ring rain could be responsible for influencing the auroras of the planet. By using this observing time from Keck, the scientists are hoping to understand exactly what that influence could be.
"The weather wasn't great at that time," O'Donoghue said of the two hours it took them to make the ring rain discovery. These new measurements are going to focus on refining those results, O'Donoghue added.
Auroras on Earth are created when charged particles from the sun shoot toward the planet. The particles are trapped in Earth's magnetic field and are pulled into the planet's atmosphere, creating the brilliant light show at the poles.
This time of the Saturnian year is particularly important for observations of Saturn because the planet's seasons are shifting. The gas giant is about to enter into its seven-year-long spring, and scientists are hoping to observe the planet's new season from as many different angles as possible.
The Keck Observatory, located on the summit of Mauna Kea in Hawaii, houses two 33-foot (10 meters) telescopes that observe in both the optical and infrared range of light.
The Cassini spacecraft — managed by NASA, the European Space Agency and the Italian Space Agency — has been in orbit around Saturn since 2004 and is now on an extended mission that will last until at least 2017.

Source of Article : space.com

2013년 4월 21일 일요일

Hubble Telescope Snaps Stunning Nebula Photo for 23rd Birthday

NASA's Hubble Space Telescope has snapped a spectacular new image of an iconic nebula to celebrate its 23 years of peering deep into the heavens.
The Hubble observatory, which launched on April 24, 1990, captured the Horsehead Nebula in infrared light, peering through obscuring veils of dust to reveal the object's hidden features.
"The result is a rather ethereal and fragile-looking structure, made of delicate folds of gas — very different to the nebula’s appearance in visible light," mission officials wrote in an image description today (April 19). The new observations allowed astronomers to create a dazzling video of the Horsehead Nebula based on Hubble's photos.
The Horsehead Nebula, also known as Barnard 33, is located about 1,500 light-years from Earth in the constellation Orion (The Hunter). The Horsehead is a huge interstellar cloud of gas and dust, like other nebulae, and the light from a nearby star gives it a beautiful glow.
The object is a popular observing target, and Hubble has taken numerous Horsehead photos over the years — including in 2001, to celebrate the telescope's 11-year anniversary.
The Horsehead's dramatic pillar is made of sterner stuff than the clouds surrouding the nebula, which have already dissipated. But the pillar will disintegrate as well in another 5 million years or so, astronomers say, and the Horsehead will go the way of the dodo.
The Hubble Space Telescope is perhaps best known for its photos in visible light. But the telescope's Wide Field Camera 3, which was installed by spacewalking astronauts in 2009, also takes crisp images in infrared wavelengths, researchers said.
Hubble, a collaboration between NASA and the European Space Agency, has made more than 1 million science observations since its 1990 launch, and it's still going strong. NASA announced last month that it had extended the telescope's science operations through April 2016.
NASA's highly anticipated successor to Hubble, the $8.8 billion James Webb Space Telescope, is slated to blast off in 2018. JWST is optimized to view in infrared light.

Source of Article : space.com

It's Time for Next Phase in Search for Alien Life, Scientists Say

With more and more Earth-like alien planets being discovered around the galaxy, humanity should now start planning out the next steps in its hunt for far-flung alien life, researchers say.
On Thursday (April 18), scientists announced the discovery of three more potentially habitable exoplanets — Kepler-62e, Kepler-62f and Kepler-69c — further suggesting that the cosmos is jam-packed with worlds capable of supporting life as we know it.
So the time is right to get the ball rolling beyond mere discovery to the detailed study and characterization of promising alien planets, researchers said — a task that will require new and more powerful instruments.
"You really want to collect the light from these planets, to figure out — take the data, not just infer —whether or not there's water, and even signs of life, on these planets," Lisa Kaltenegger of the Max Planck Institute for Astronomy and the Harvard-Smithsonian Center for Astrophysics, who was part of the team that discovered Kepler-62e and f, said during a press conference Thursday.
Billions of Earth-like planets
As their names suggest, the three newfound planets were discovered by NASA's prolific Kepler space telescope, which has spotted more than 2,700 potential alien worlds since its March 2009 launch. Just 122 have been confirmed to date, but mission scientists expect more than 90 percent will end up being the real deal.
The $600 million Kepler mission was designed to determine how common Earth-like planets are around the Milky Way galaxy. Its observations so far suggest our home planet may not be so special.
For example, astronomers recently used Kepler data to estimate that 6 percent of the galaxy's 75 billion or so red dwarfs — stars smaller and dimmer than the sun — likely host habitable, roughly Earth-size planets.
That works out to a minimum of 4.5 billion "alien Earths," the closest of which may be just 13 light-years or so away, according to the study.
While Kepler's work is not done, the instrument has already laid the foundation for the next generation of exoplanet missions, mission team members said.
"In many ways, Kepler was a scout. It scouted deep into the galaxy to find out what the frequencies were, and to show there were a lot of planets to find. It's accomplished that," Kepler science principal investigator Bill Borucki of NASA's Ames Research Center in Moffett Field, Calif., who led the team that found Kepler-62e and f, said at Thursday's press conference.
"And now these new missions will come online and give us more information about these planets," Borucki added, referring to efforts such as NASA's Transiting Exoplanet Survey Satellite, which will launch in 2017 to search for nearby alien worlds. "But the big step is that step where we first start measuring the composition of the atmospheres, and that will be a very technologically difficult task."
Scanning exoplanet air
Borucki and other researchers are keen to get a look at exoplanet atmospheres because the gases present in them can reveal a great deal about the worlds' potential to host life.
Finding carbon dioxide, water and oxygen would bolster the case for a planet's habitability, for example, while spotting extremely complex compounds could make headlines around the world.
"If there are freons, I mean, you've got it made," Borucki said. "Obviously, intelligent life is there."
Studying exoplanets' air will require blocking out the overwhelming glare of their parent stars, which are a billion times brighter than the planets themselves, Borucki said.
That's a daunting task but not an impossible one. A decade ago, in fact, a proposed NASA mission called the Terrestrial Planet Finder (TPF) devised two different techniques to study exoplanet atmospheres, with a possible maximum range of 30 light-years or more.
Funding for TPF never materialized, and the project is now regarded as cancelled. But Borucki expressed confidence that the ongoing exoplanet revolution sparked in large part by Kepler will bring the project back, though not necessarily under the same name.
"Undoubtedly, it at some point will be reinstated," he told SPACE.com. "As we progress in the exploration of the galaxy, looking for life, we must start looking at the atmospheres. Everybody recognizes that."

Source of Article : space.com

2013년 4월 17일 수요일

Baby Boom: Ancient Galaxy Fires Out New Stars at Record Pace

Astronomers peering into the early history of the universe have spotted perhaps the most productive star-forming galaxy ever found.
Known as HFLS 3, the young galaxy churns out about 3,000 new stars each year — more than 2,000 times as many as the Milky Way averages, and up to 20 times more than the number created by similar galaxies today.
The massive starburst galaxy existed only 880 million years after the Big Bang that created our universe 13.8 billion years ago, making HFLS 3 the most distant known pure starburst galaxy.

Supersizing stellar creation
Starburst galaxies exist today, burning through their stores of dust and gas to produce stars at a fantastic rate. But HFLS 3 is 15 to 20 times larger, and produces 15 to 20 times more stars, than similar current galaxies.
The difference is in the dust. Early in the history of the universe, when less dust had been converted to stars, galaxies such as HFLS 3 had access to more raw materials.
"The same processes are involved, but just 'supersized,'"  Riechers said.
One of tens of thousands of early starburst galaxies detected by the European Space Agency's Herschel Space Observatory, HFLS 3 attracted attention because it appeared very red among the rest, which indicated the possibility of greater distance. Riechers and a team of international astronomers used a suite of instruments from around the world to study the distant structure.
"Finding this galaxy was like looking for a needle in a haystack," Riechers said.
Although light travels at an extremely rapid pace, it still takes time to cross vast distances. When astronomers examine an object at a great distance, they see it as it was when light left the source, rather than the way it looks today.
Because it took about 12.8 billion years for HFLS 3's light to reach us, astronomers know they are seeing the galaxy when the universe was only about 6 percent of its current age.
The galaxy itself would have looked very different from the Milky Way to hypothetical contemporary observers. While our skies are mostly clear, the center of our galaxy is shrouded in dust and gas, making it impossible to peer through.
"In this new early starburst galaxy, our sky would look like this in pretty much every direction we looked," Riechers said.
The high rate of stellar formation would give rise to more young blue stars, and supernovae
, the explosive death of stars, would be thousands as time as common.
"It would make our own galaxy look like a fairly boring place in comparison," Riechers said.
But the dusty sky won't last forever. With its rapid stellar creation, it won't take long for HFLS 3 to burn through its dust and gas.
"If the galaxy keeps going at full speed, it can consume all of its vast gas reservoir in only about 36 million years," Riechers said. That's short on astronomical time scales, only a tiny fraction of the lifetime of the galaxy.
Eventually, the galaxy will calm down, forming only a handful of stars each year until it acquires more gas, either from its environment or by merging with another galaxy. Over its lifetime, it is likely to have undergone several bursts of stellar production, followed by dry periods.
"One way or another, the starburst is not going to last forever," Riechers said.
The research was published online today (April 17) in the journal Nature.
The structure of the universe
Although dust and gas were more plentiful soon after the Big Bang, starburst galaxies like HFLS 3 were extremely rare before star formation picked up. According to Riechers, they were at least 10,000 to 100,000 times less common than "normal" galaxies early in the history of the universe.
Over time, they became more plentiful, but as dust supplies depleted, they again became more scarce. Part of the reason for the rarity is because it takes time for large-scale structures to form.
"Models predict that the most massive, most intensely star-forming galaxies can only form once a certain time has passed," Riechers said.
Pinning a date on HFLS 3 helps astronomers understand more about galactic growth and evolution over time. Comparing the early starburst galaxy to later, similar structures can also reveal any changes in their properties, researchers said.

Source of Article : space.com

2013년 4월 16일 화요일

Space Station Lands in Houston in State-of-the-Art NASA Exhibit

NASA has a new "stage" to expose and educate the public about the work behind — and on board — the International Space Station.
More than a year in the making, NASA and Space Center Houston, the visitor center for the agency's Johnson Space Center in Texas, put the final touches on a new interactive exhibit and special effects live stage show that highlights how the orbiting outpost came to be, what life is like on board and how it is being used to conduct science.
The 3000-square-foot (280 square meters) display was inspired by NASA's traveling exhibit "Destination Station" (hosted currently at Atlanta's Fernbank Science Center until May 18). But instead of simply recreating the mobile exhibition, NASA's International Space Station Program worked with the external relations office at Johnson and Space Center Houston to enhance and expand the display into a brand-new experience for guests.
"This [new] exhibition highlights, through the use of a live performance, static graphic elements, hardware, astronaut personal effects, video content and interactive software programs, the international partnership which assembled this orbiting laboratory, its human presence which works and lives on board, and the complex research and science that is taking place which benefits all humankind," NASA wrote about the exhibit.
Destination Station 2.0
Space Center Houston began building the exhibit about a year ago by reconfiguring the International Space Station — or rather a large detailed model of the orbiting complex.
Suspended from the ceiling, the scale model was updated to reflect the final assembly of the space station, including removing a once-docked replica of the now-retired space shuttle. The model was then re-hung in front of a mural of the Earth, placing it into the context of the new display.
Underneath the not-so-miniature station is a new mockup of a Mission Control console. Nearby, one of the canisters used to transport the orbiting laboratory's power-providing solar arrays is also on display with a sample strip of the cells used to generate electricity for the station.
The Mission Control monitors display the "Space Station Live!" website, which provides access to live data from the real space station as received through the real Mission Control, located nearby at the Johnson Space Center. Not only can visitors use the replica console to learn what the astronauts and cosmonauts on board the station are doing in space in real time, but they can find when the orbiting complex can be seen flying over their homes.
Venturing further into the exhibit, guests can see a training mockup of the space station's multi-window Cupola, a full-size model of the outpost's robotic resident Robonaut 2, and look inside both a crew member's living quarters and the onboard waste containment system, or toilet.
Wall-size video displays introduce the public to the many science racks that support the hundreds of experiments being hosted on board the space station at any one time and to the equipment used by the astronauts to first build and now maintain the complex.
At the center of the new display are two large glass cases that showcase artifacts from the space station's first 15 years in orbit. One case exhibits test samples and a flown hatch cover that show the impact, literally, that micrometeoroid debris has on the outpost's exterior.
The second case features crewmembers' clothing and personal items, on loan from the astronauts themselves. Included in the display are the tennis balls used in the first attempt at juggling in orbit, a small pink romper flown for an astronaut whose baby girl was to be born while he was in space, and a costume shirt from the television series "Star Trek: The Next Generation" that was worn by a crewmember on board the real-life space station.
The (special) effects of life in space
Where the new exhibit really comes alive is during a live stage show about what life is like for astronauts on board the space station.
Set on a stage designed to look like the inside of a space station module, Space Center Houston's "Mission Briefing Officers" guide guests through how astronauts eat, sleep and work aboard the orbiting laboratory.
The "Living in Space" show pre-dates the new exhibit but has been enhanced with state-of-the-art special effects to match the high-tech design of the surrounding display.
"The storyline is still how do the astronauts eat, sleep in space, how do they exercise, they go to the bathroom and what kind of work they do. That part hasn't changed but the way that we tell that story has," Paul Spana, exhibits manager at Space Center Houston, told collectSPACE.com.
"What is brand-new about the show, and what I think is the coolest part, is this new special effect," Spana said. "The visitor does not see the equipment, but in the ceiling we have two large video projectors and it is a technique called 'video mapping.' The back wall of the module is actually a projection screen."
Similar to the effects featured in the "Harry Potter and the Forbidden Journey" ride at Universal Studios Orlando in Florida, the projection technology creates the appearance that the drawers aboard the space station are opening and that items are able to float out. At one point, water globules, seemingly weightless, even float across the stage and are "absorbed" by a real-life towel.
Visiting the space station
The new International Space Station exhibit, which is now open for the public to experience, is included with regular admission to Space Center Houston.
It's a permanent exhibition, and NASA and Space Center Houston plan to continue expanding the display, showcasing the latest developments aboard the space station, as well as adding more flown and astronaut artifacts as they become available.
"You can come here and find out who those people are that are in space today, you can find out about what they are doing, you can find out how to see the space station from your own backyard and then you can learn why we are doing all of this," Spana said.

Source of Article : space.com

Virgin Galactic's SpaceShipTwo Makes Stunning Leap Toward Private Spaceflight

A new private spaceship is one step closer to flying its first passengers after acing a spectacular test flight over the California desert last week.
Virgin Galactic's suborbital SpaceShipTwo successfully conducted its first "cold flow" flight test above the Mojave Desert last Friday (April 12). During the test, oxidizer was run through the rocket's propulsion system and out the back nozzle of the ship, though the vehicle's rocket engine was not turned on.
"As well as providing further qualifying evidence that the rocket system is flight-ready, the test also provided a stunning spectacle due to the oxidizer contrail and for the first time gave a taste of what SpaceShipTwo will look like as it powers to space," Virgin Galactic officials wrote in a statement.
During the most recent test — which comes on the heels of the ship's 24th successful drop test on April 3 — the space plane was flown high into the sky by WhiteKnightTwo, its carrier aircraft. After being released from the plane, SpaceShipTwo glided smoothly back to the ground, leaving a contrail of oxidizer in its wake.
The next big step for the commercial spaceflight company appears to be conducting a full flight test, igniting the rocket in the air.
"The upcoming first powered flight of SpaceshipTwo is in many ways the most significant milestone to date, being the first time that the spaceship has flown with all systems installed and fully operational," Virgin Galactic officials wrote.
The company has not released an expected date for a powered test flight
Once SpaceShipTwo is operational, WhiteKnightTwo will carry the vehicle up to an altitude of about 50,000 feet (15,240 meters) before releasing it.
After separation, SpaceShipTwo will accelerate to 2,500 mph (4,000 km/h) and eventually pass an altitude of 62 miles (100 kilometers), the point at which passengers are considered astronauts. The spaceship will reach a peak altitude of 68 miles (110 km), giving the six passengers and two pilots about five minutes of weightlessness. Upon re-entry, SpaceShipTwo will be able to land on a conventional runway.
A seat on board a SpaceShipTwo flight costs $200,000. More than 550 people have put down deposits to reserve a spot, company officials say.
Virgin Galactic was founded by British billionaire Sir Richard Branson in 2004 to offer private trips to space for paying passengers. The company's SpaceShipTwo vehicles and their giant WhiteKnightTwo carrier aircraft were developed by the Mojave, Calif.-based company Scaled Composites.

Source of Article : space.com

Mars Colony Project to Begin Astronaut Search by July

A nonprofit organization that aims to land four astronauts on Mars in 2023 will kick off its two-year, televised search for Red Planet explorers by this summer.
The Netherlands-based Mars One will begin accepting application videos sometime between now and July, charging a fee to weed out folks who aren't serious about their candidacy. The group hopes to raise millions of dollars this way, with the proceeds paying for the ongoing selection process and technology studies.
"We expect a million applications with 1-minute videos, and hopefully some of those videos will go viral,” Mars One co-founder and chief executive officer Bas Lansdorp told SPACE.com on April 10. He was in London to speak to the British Interplanetary Society (BIS) that day. 
Mars One now has 45,000 people registered for its mailing list and has already received 10,000 emails from interested individuals, Lansdorp added. The organization will unveil more details about its astronaut selection process at a press conference in New York City on April 22.
A one-way trip to Mars
Mars One is casting a wide net, seeking applicants from all over the world. Application fees will vary from country to country, with folks from poorer nations getting a price break, Lansdorp said. The maximum fee will apparently be $25.
Anyone who is at least 18 years old can apply by sending in a video explaining why he or she should be selected. But prospective colonists must be prepared to say goodbye to Earth forever; there are no plans at this point to bring Mars One astronauts home.
By July 2015, Mars One wants to have 24 astronauts, organized into six teams of four people. Those teams then face seven years of training that will include spending three months at a time in a replica of the Mars colony.
"We will give them all the most stressful situations,” Lansdorp told the BIS audience on April 10, adding that the training base will have a 40-minute communications delay to replicate the time lag that would exist due to the vast distance between Earth and Mars.
Mars One officials expect some individuals and teams to fail these tests, so from 2015 on, the nonprofit will have an annual process to select 12 people (in three teams of four).
"We will always have about 10 groups [of four] in training, so if one group drops out, there will be replacement crews," Lansdorp told SPACE.com. This will continue even after 2023, because Mars One plans to send more colonists to the Red Planet every two years for as long as funding levels will allow.
Interplanetary 'Big Brother'
Mars One estimates that it needs $6 billion to send the first four astronauts to Mars. This money will cover developing the landing systems, habitats, Mars Transit Vehicle (MTV), rovers, solar arrays and other technologies associated with the colony, as well as pay for the crew's journey from Earth.
Every subsequent crew trip would cost $4 billion, Lansdorp told SPACE.com. Just sending a supply lander would cost $250 million.
Mars One plans to raise this money largely through a global reality television series that will follow the colonization effort from astronaut selection to the first landing and the settlement’s expansion.
The audience will vote for who gets to go to Mars from a pool of candidates selected by Mars One’s experts. Lansdorp points to the 2012 London Olympics and the $4 billion it generated from television revenues over its three weeks as evidence that such a funding plan can work.
Meanwhile, the application video revenue will finance early technology studies and prove there is demand for a television show.
“We can prove to the broadcasters that there is real demand and interest, and we will start negotiations after the [astronaut] selection procedure begins,” Lansdorp told SPACE.com.
Beyond the applicant videos and television show, future revenues include crowdfunding, exploiting the technologies developed for Earth’s markets and doing research on Mars for governments. For example, Mars One could eventually send samples of Martian soil to Earth, officials say.
Mission details taking shape
While the Mars spacecraft has yet to be designed, Lansdorp told the BIS audience that for the 210-day journey, the vehicle would have a hollow 660-gallon (2,500 liters) water tank with four compartments.
Astronauts would sleep in this area and use it as shelter from extreme solar radiation events. The water equates to a 9.84-inch (25 centimeters) column for radiation protection, which Lansdorp told the BIS is what NASA and the European Space Agency (ESA) suggest for a return mission.
When the first team of four lands at the settlement’s location on April 24, 2023, the settlers will find a colony whose habitats and solar arrays started working before they left Earth. Lansdorp told SPACE.com that the colony will be located between 40 and 45 degrees north latitude.
"We want to be as south as possible for sunlight and north enough for water," he said, adding that the colony would be at a location that is 1.55 miles (2.5 kilometers) lower than Mars’ average ground level, to give the arriving spacecraft more time to land.
The colony will initially have rovers, two habitats, two life support landers and two supply landers. Mars One is designing five types of landers for life support, supplies, habitat and those that land the crew and rovers. The first equipment to be sent to Mars will be a communications satellite, a demonstration rover and a 5,500-pound (2,500 kilograms) supply lander, officials said.
"We have a conceptual rover right now. It is very likely there will be two rovers — one trailer rover and one intelligent rover that does all the advanced tasks,” Lansdorp told SPACE.com. The trailer rover will move landers from their landing point to the settlement, a distance not expected to exceed about 1 mile (1.6 km).
The colony’s habitats will be connected by fabric tunnels and covered in 6 feet (1.8 m) of Martian soil, to provide radiation protection. Lansdorp told the BIS audience that with the colony’s expected outdoor activities, the colonists will get a radiation dose over 10 years equal to that of ESA’s maximum allowed for its astronauts, which he described as “very safe."
At the same time the first team lands, the second crew’s habitat lander will also arrive. As well as being ready for the second crew's 2025 arrival, this habitat can be used by the first crew if they encounter problems with their own equipment.
The colony will have inflatable greenhouses and use water from the Martian soil and nitrogen from the atmosphere to grow crops. The crew will cultivate rice, algae and insects for their high protein content and will also likely grow mushrooms, along with tomatoes and other plants.
Tapping private industry
Solar rather than nuclear power will be used for the base, Lansdorp said, and all the landers may be larger versions of SpaceX's Dragon spacecraft.
“We’ve discussed upscaling of Dragon capsule with SpaceX,” Lansdorp told the BIS audience.
In March, Mars One announced it had signed a contract with Paragon Space Development Corp. for a conceptual design study into life support and space suit systems.
Paragon has also been contracted by Dennis Tito for his Inspiration Mars project, which aims to launch two people on a Mars flyby mission in 2018 that will neither land on nor orbit the Red Planet. Lansdorp is slated to meet Tito in May in Washington, D.C.
As well as Paragon and SpaceX, Lansdorp is in discussions with Canada’s MDA Robotics for the rovers; Italy’s Thales Alenia Space for the MTV; ILC Dover, Astrobiotic and the U.K.’s Surrey Satellite Technology.
Lansdorp declined to answer questions about how much money Mars One has already raised, saying only that it's enough to start the selection process and to fund the Paragon contract. However, Mars One has named its first investors. Described as silver sponsors, they include Verkkokauppa.com, Finland’s second largest consumer electronics retailer, and Byte Internet, a Web hosting service.

Source of Article : space.com

Mysterious Energy Bursts May Be Death Knell of Gigantic Stars

A new type of powerful, long-lasting explosion deep in space may be the death knell of gigantic stars, scientists say.
Star explosions (called supernovas) can give off high-powered flashes of radiation known as gamma-ray bursts. These bursts usually fall into two categories: ones that last less than two seconds, and ones that last for several minutes. But this new type of explosion can create a gamma-ray burst that goes on for much longer — up to several hours.
"These events are amongst the biggest explosions in nature, yet we’re only just beginning to find them," astronomer Andrew Levan of the University of Warwick in the United Kingdom said in a statement. "It really shows us that the universe is a much more violent and varied place than we’d imagined."
Astronomers spied the first of these odd bursts — which lasted half an hour — on Dec. 25, 2010. Scientists did not know how far away the source was, but they offered two possible explanations for the origin of the Christmas Day burst.
One theory suggested that the burst came from an asteroid or comet in our galaxy being ripped apart by the gravity of a dense neutron star (the collapsed stellar remnant of a supernova). Another theory held that a supernova in a galaxy 3.5 billion light-years away caused the explosive rays.
Now, after studying several examples of such cosmic blasts, Levan and his colleagues have found that the Christmas Day burst occurred in a galaxy much more distant than previously thought.
The researchers used data collected with the Gemini Telescope in Hawaii to calculate that the lengthy gamma-ray burst had a "redshift" of 0.847, which translates to a distance of 7 billion light-years away, or about halfway to the edge of the observable universe.

Given the burst's location, Levan and colleagues think it was caused by a star known as a supergiant, which started out with 20 times the mass of the sun and grew to contain as much as 1,000 solar masses. At that size, it would have a radius of 1 billion miles (1.6 billion kilometers), making it one of the biggest and brightest stars in the universe.
The abnormally long duration of the Christmas Day burst and several others may be due to the enormous size of the supergiants when they exploded, the scientists theorize.
More common, relatively short types of gamma-ray bursts are caused by a star collapsing into a black hole at its center. As the black hole sucks in matter, some of that matter escapes and forms a jet of energy that streams out in two directions, generating gamma rays.
The jets of matter must travel very close to the speed of light in order to escape the black hole's gravity, so they ripple through the star in just a few seconds. In a supergiant, however, the explosion has to travel through much more material, resulting in a longer burst.

Source of Article : space.com

2013년 4월 11일 목요일

Nuclear Fusion Rocket Could Reach Mars in 30 Days

Nuclear fusion, the energy source that fuels the sun and other active stars, could one day propel rockets that allow humans to go to Mars and back in 30 days, researchers say.
Fusion-powered rockets promise to solve problems of deep-space travel that have long plagued plans for manned missions to Mars — long journeys, high costs and health risks, among them. Scientists at the University of Washington and a space-propulsion company named MSNW say they are getting to closer to creating a feasible fuel for travel to other planets.
"Using existing rocket fuels, it's nearly impossible for humans to explore much beyond Earth," John Slough, a UW research associate professor of aeronautics and astronautics, said in a statement. "We are hoping to give us a much more powerful source of energy in space that could eventually lead to making interplanetary travel commonplace."
Previous estimates have found that a roundtrip manned mission to Mars would require about 500 days of space travel. Slough, who is president of MSNW, and his colleagues calculated that a rocket powered by fusion would make 30- and 90-day expeditions to Mars possible. The project is funded in part through NASA's Innovative Advanced Concepts Program and received a second round of funding under the program in March.
For comparison, past NASA studies have centered on Mars flights that would take two years to complete, and could cost $12 billion just to launch the fuel needed for the mission, according to Slough's team.
Nuclear fusion occurs when the nuclei of two or more atoms combine, resulting in a release of energy. The sun and other stars convert this energy into light, and the same process gives hydrogen bombs their destructive power.
But to use fusion to power a manned spacecraft, a more controlled process is needed.
Lab tests by Slough and his team suggest that nuclear fusion could occur by compressing a specially developed type of plasma to high pressure with a magnetic field. A sand-grain-sized bit of this material would have the same amount of energy as current rocket fuel, the team says.
To get this fuel to propel a rocket to Mars, the team says a powerful magnetic field could be used to cause large metal rings (likely made of lithium) to collapse around the plasma material, compressing it to a fusion state, but only for a few microseconds. Energy from these quick fusion reactions would heat up and ionize the shell of metal formed by the crushed rings. The hot, ionized metal would be shot out of the rocket nozzle at a high speed. Repeating this process roughly every minute would propel the spacecraft, the researchers say.
Slough said the design is fairly straightforward. The next step of the team's work is to combine each of the isolated tests they've already completed successfully into a final experiment that produces fusion using this technology.
"We hope we can interest the world with the fact that fusion isn't always 40 years away and doesn't always cost $2 billion," Slough said in a statement.

Source of Article : space.com

Sun Unleashes Biggest Solar Flare of the Year Yet

The most powerful solar flare of the year erupted from the sun today (April 11) sparking a temporary radio blackout on Earth, NASA officials say.
The solar flare occurred at 3:16 a.m. EDT (0716 GMT) and registered as a M6.5-class sun storm, a relatively mid-level flare on the scale of solar tempests. It coincided with an eruption of super-hot solar plasma known as a coronal mass ejection.
"This is the strongest flare seen so far in 2013," NASA spokeswoman Karen Fox explained in a statement. "Increased numbers of flares are quite common at the moment, since the sun's normal 11-year cycle is ramping up toward solar maximum, which is expected in late 2013."
NASA's sun-watching Solar Dynamics Observatory recorded a stunning video of the strongest solar flare of 2013, showing it extreme detail. The spacecraft is one of several space-based observatories keeping track of the sun's solar weather events.
NASA officials dubbed today's solar flare as a "spring fling" for the sun, which has been relatively calm as it heads into its peak activity period.
Today's M-class solar flare was about 10 times weaker than X-class flares, which are the strongest flares the sun can unleash. M-class solar flares are the weakest solar events that can still trigger space weather effects near Earth, such as communications interruptions or spectacular northern lights displays.
The solar flare triggered a short-lived radio communications blackout on Earth that registered as an R2 event (on a scale of R1 to R5), according to space weather scales maintained NOAA, Fox added.
When aimed directly at Earth, major solar flares and coronal mass ejections can pose a threat to astronauts and satellites in orbit. They can interfere with GPS navigation and communications satellite signals in space, as well as impair power systems infrastructure on Earth.
Fox said NASA officials are tracking the coronal mass ejection to see if it poses any space weather concerns for Earth. Meanwhile, the Solar Dynamics Observatory and other space observatories will continue to monitor the sun's activity.
"Humans have tracked this solar cycle continuously since it was discovered, and it is normal for there to be many flares a day during the sun's peak activity," Fox explained.

Source of Article : space.com

2013년 4월 10일 수요일

Black Hole Caught Snacking on 'Super Jupiter' Planet

In a cosmic first, astronomers have discovered a black hole chowing down on what may be a giant rogue planet.
The supermassive black hole didn't finish off its meal, which scientists say was either a huge Jupiter-like planet wandering freely through space or a brown dwarf, a strange object that's larger than a planet yet still too small to trigger the internal fusion reactions required to become a full-fledged star.
“This is the first time where we have seen the disruption of a substellar object by a black hole," study co-author Roland Walter, of the Observatory of Geneva in Switzerland, said in a statement. "We estimate that only its external layers were eaten by the black hole, amounting to about 10 percent of the object’s total mass, and that a denser core has been left orbiting the black hole."
Researchers made the discovery using the European Space Agency's Integral space observatory, which noticed an X-ray flare coming from the center of a galaxy 47 million light-years away called NGC 4845.
Follow-up observations by several other instruments — including ESA's XMM-Newton and NASA's Swift space telescopes and Japan's MAXI X-ray monitor on the International Space Station — allowed the team to trace the outburst's maximum to January 2011, when NGC 4845 brightened by a factor of 1,000 before dimming again over the next year or so.
"The observation was completely unexpected, from a galaxy that has been quiet for at least 20–30 years," lead author Marek Nikolajuk, of the University of Bialystok in Poland, said in a statement.
By studying the flare's properties, the team determined that the emission likely resulted when NGC 4845's central black hole — which is as massive as 300,000 suns — fed on an object with a mass between 14 and 30 times that of Jupiter.
That mass range corresponds to a brown dwarf, also known as a failed star. But it's also possible that the unfortunate object is quite a bit smaller, with a mass just a few times that of Jupiter, researchers said. If that's the case, then the galaxy's black hole was probably ripping apart a free-floating gas giant planet.
Such "rogue planets," which have been ejected from their native solar systems by gravitational interactions, are thought to be incredibly common throughout the universe. One recent study, for example, estimated that rogues outnumber "normal" planets with obvious parent stars by at least 50 percent in our own Milky Way galaxy.
The Milky Way's enormous central black hole is set to have a meal of its own soon. A gas cloud as massive as several Earths is spiraling toward the black hole and should be gobbled up later this year, astronomers say.
Observing more such events should help researchers better understand how black holes feed.
"Estimates are that events like these may be detectable every few years in galaxies around us, and if we spot them, Integral, along with other high-energy space observatories, will be able to watch them play out just as it did with NGC 4845," said Christoph Winkler, ESA's Integral project scientist.

Source of Article : space.com

2013년 4월 4일 목요일

Curiosity Rover Goes Solo on Mars for 1st Time Today

NASA's Mars rover Curiosity will be on its own for the first time over the next four weeks, thanks to an unfavorable alignment of the Red Planet, Earth and the sun.
Curiosity's handlers don't plan to send any commands to the car-size robot from today (April 4) through May 1. The sun comes between Earth and the Red Planet during this time, in a formation known as a Mars solar conjunction.
"The [communications] moratorium is a precaution against possible interference by the sun corrupting a command sent to the rover," NASA officials wrote last week in a Curiosity rover mission update.
While some mission team members may take advantage of the break to lie on a beach somewhere, Curiosity itself won't necessarily be idle. The 1-ton rover can continue doing stationary science work at a site known as Yellowknife Bay using commands sent up in advance, officials have said.
NASA's other active Mars spacecraft — the Opportunity rover, Mars Reconnaissance Orbiter (MRO) and Mars Odyssey orbiter — will also go solo during conjunction, though for shorter periods of time. These robotic explorers won't receive any new commands from April 9 through April 26.
MRO and Mars Odyssey help relay data from Opportunity and Curiosity to Earth. MRO goes into a four-week-long record-only mode today, but Odyssey will keep sending rover information home throughout conjunction, helping engineers keep tabs on Opportunity and Curiosity.
"We will maintain visibility of rover status two ways," Torsten Zorn, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement last month. Zorn is conjunction planning leader for Curiosity's engineering operations team. "First, Curiosity will be sending daily beeps directly to Earth. Our second line of visibility is in the Odyssey relays."
Mars solar conjunctions come around evey 26 months, so veterans of NASA's various Mars campaigns are used to dealing with them. Opportunity is weathering its fifth conjunction, for example, and Odyssey its sixth.
But this will be the first conjunction experience for Curiosity, which landed inside Mars' huge Gale Crater this past August to determine if the Red Planet could ever have supported microbial life.
The Curiosity team has already achieved its main mission goal, announcing last month that the Yellowknife Bay area was a wet, habitable environment — perhaps a lake — billions of years ago. Researchers came to this conclusion after studying analyses Curiosity performed of material drilled from deep within an outcrop in early February.
The rover team wants to drill another rock to confirm and extend what Curiosity has already observed. But this second drilling operation won't take place until after conjunction, officials have said.

Source of Article : space.com