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SHAFAQNA (Shia International News Association) – Unless space debris is actively tackled, some satellite orbits will become extremely hazardous over the next 200 years, a new study suggests.

The research found that catastrophic collisions would likely occur every five to nine years at the altitudes used principally to observe the Earth.

And the scientists who did the work say their results are optimistic - the real outcome would probably be far worse.

To date, there have been just a handful of major collisions in the space age.

The study was conducted for the Inter-Agency Space Debris Coordination Committee.

This is the global forum through which world governments discuss the issue of "space junk" - abandoned rocket stages, defunct satellites and their exploded fragments.

The space agencies of Europe, the US, Italy, the UK, Japan and India all contributed to the latest research, each one using their own experts and methodology to model the future space environment.

Simulated futures

They were most concerned with low-Earth orbit (that is, below 2,000km in altitude). This is where the majority of missions returning critical Earth-observation data tend to operate.

All six modelling groups came out with broadly the same finding - a steady increase in the numbers of objects 10cm and bigger over the 200-year period.

This growth was driven mostly by collisions between objects at altitudes between 700km and 1,000km.

The low-end projection was for a 19% increase; the high-end forecast was for a 36% rise. Taken together, the growth was 30%. These are averages of hundreds of simulations.

For the cumulative number of catastrophic collisions over the period, the range went from just over 20 to just under 40.

Somewhat worryingly, the forecasting work made some optimistic assumptions.

One was a 90% compliance with the "25-year rule". This is a best-practice time-limit adopted by the world's space agencies for the removal of their equipment from orbit once it has completed its mission.

The other was the idea that there would be no more explosions from half-empty fuel and pressure tanks, and from old batteries - a significant cause of debris fragments to date.

Concept development

"We're certainly not at 90% compliance with the 25-year rule yet, and we see explosion events on average about three times a year," explained Dr Hugh Lewis, who detailed the research findings at the 6th European Conference on Space Debris in Darmstadt, Germany, on Monday.

"It is fair to say this is an optimistic look forward, and the situation will be worse than what we presented in the study," the UK Space Agency delegate to the IADC told BBC News.

"So one message from our study is that we need to do better with these debris-mitigation measures, but even with that we need to consider other approaches as well. One of the options obviously is active debris removal."

Research groups around the world are devising strategies to catch old rocket bodies and satellites, to pull them out of orbit.

Previous modelling work has indicated that removing just a few key items each year could have a significant limiting effect on the growth of debris.

Most ideas include attaching a propulsion module to a redundant body, perhaps via a hook or robotic clamp.

Harpoon idea

One UK concept under development is a harpoon. This would be fired at the hapless target from close range.

A propulsion pack tethered to the projectile would then tug the junk downwards, to burn up in the atmosphere.

When the BBC first reported this concept back in October, the harpoon was being test-fired over a short range of just 2m.

The latest testing, to be reported at the Darmstadt conference this week, has seen the harpoon fired over a much longer distance and at a more realistic, rotating target.

"Our tests have progressed really well, and everything seems to be scaling as expected," explained Dr Jaime Reed, from Astrium UK.

"We've now upgraded to a much more powerful gun and have been firing the harpoon over 10m - the sort of distance we'd expect to have to cover on a real debris-removal mission.

"Our harpoon also now has a shock absorber on it to make sure it doesn't go too far inside the satellite, and we've been firing it with the tether attached. It's very stable in flight."

Chinese test

There are some 20,000 man-made objects in orbit that are currently being monitored regularly. About two-thirds of this population is in Low-Earth orbit.

These are just the big, easy-to-see items, however. Moving around unseen are an estimated 500,000 particles ranging in size between 1-10cm across, and perhaps tens of millions of other particles smaller than 1cm.

All of this material is travelling at several kilometres per second - sufficient velocity for even the smallest fragment to become a damaging projectile if it strikes an operational space mission.

Two key events have added significantly to the debris problem in recent years.

The first was the destructive anti-satellite test conducted by the Chinese in 2007 on one of their own retired weather spacecraft.

The other, in 2009, was the collision between the Cosmos 2251 and Iridium 33 satellites.

Taken together, these two events essentially negated all the mitigation gains that had been made over the previous 20 years to reduce junk production from spent rocket explosions.-www.shafaqna.com/English

Source: BBC

SHAFAQNA (Shia International News Association) – A little over 50 years ago, no one on Earth knew what would happen when a human being was launched into space. That all changed on this day in 1961, when Yuri Gagarin, a Soviet military pilot and cosmonaut, hurtled into orbit aboard Vostok 1.

He circled the Earth once, reporting that he was feeling "excellent" and could see "rivers and folds in the terrain" and different kinds of clouds. "Beautiful" was his simple description of the view. Weightlessness, he said, felt "pleasant." (See pictures of Gagarin's flight.)

In the decades since Gagarin became the first person in space, what began as a politically fraught competition has yielded men on the moon, space walks, and visions of putting people on Mars. Here's a look at some of the important changes in space travel that occurred along the way.

Politics

Gagarin's flight represented a triumph for the Soviet Union during the heat of the Cold War, from which both the U.S. and Russian space programs were born. "The space race was partly about impressing the living daylights out of other nations because the science and technology are closely aligned with military capability," says Roger Launius, senior curator and space historian at the Smithsonian's National Air and Space Museum.

The Soviets, notes Launius, kept secret for years the fact that Gagarin had to bail out of his spacecraft with a parachute several miles above ground during the landing. The spherical Vostok capsule lacked thrusters to slow it down, and requiring Gagarin to eject before reaching the ground might have meant the mission didn't qualify as the first successful human space flight. "They had no idea what was going to happen—the capsule could have left a big hole in the ground," Launius says. (See pictures of space suit evolution.)

Nowadays the U.S. and Russia collaborate regularly, with cross-training and joint flights to the International Space Station (ISS). The launch pad from which Gagarin took off—Baikonur Cosmodrome in what is now Kazakhstan—is still used today, most recently to send two cosmonauts and a U.S. astronaut to the ISS in March.

Escaping Earth

Gagarin's mission required a rocket that could propel his spacecraft fast enough to sustain a speed of some 17,000 miles per hour (27,359 kilometers an hour), known as orbital velocity. Less than a decade later, NASA's Saturn V rocket achieved escape velocity—the speed required to escape Earth's gravitational pull (25,039 miles per hour or 40,320 kilometers per hour). This milestone made it possible to put men on the moon.

Saturn V stood taller than the Statue of Liberty and generated more power than 85 Hoover Dams. It was a thing of beauty, and resulted in the first human footsteps on extraterrestrial terrain, when Neil Armstrong stepped onto the moon in 1969. More Apollo missions followed, and Saturn V took its final bow in 1973, when it launched the Skylab space station into orbit.

Creature Comforts

Gagarin traveled in what was essentially a giant ball and didn't have the capacity to control his spacecraft. If he were to take a tour of the International Space Station today, he might be impressed with the amenities: exercise bikes, barbeque beef brisket—even a choice of toilet papers.

"There wasn't a lot of interest early on in making cosmonauts comfortable—they were there to do a task," says Launius. "It's only with longer-term missions that you have to worry about comfort."

Hence the memorable shower aboard Skylab, NASA's space station during the 1970's and first attempt to test the ability of humans to work and live in space for extended periods. The weight of water and the large equipment required to recycle it, however, proved too much of a burden, says NASA spokesman Jay Bolden, leaving today's space dwellers resorting to "basic squirts of water and soap on washcloths for sponge baths."

Space Medicine

Gagarin's mission lasted 108 minutes, so he didn't have to eat. But the cosmonaut who followed him into space, German Titov, went up for more than a day. People wondered: Would he be able to swallow food?

Today's big questions about space travel and the human body involve bone loss and radiation exposure, but fundamental questions existed even then, notes NASA's chief historian Bill Barry. "People asked if you could swallow without gravity. One of Titov's experiments was to eat something in space," he says.

Another mystery was "space sickness," involving severe nausea. Titov suffered a bad case of it, which worried the Soviets greatly, says Barry. Now it's known to be common among space travelers and even bears a medical name: space adaptation syndrome.

Modern studies focus on the effects of long-term space travel, as eyes turn to Mars and people spend months—even longer than a year in the case of cosmonaut Valeri Polyakov—working in space. "In less than a week we see signs of degradation in the human body," says Launius of the Smithsonian. "I would contend that the real challenge for space travel is biomedical, not technological."

Commercialization

Perhaps the most remarkable change in space travel since Gagarin's historic flight is how routine it's become—and possible for the right price.

Millions of dollars have landed private citizens a seat on Russian spacecraft, though Russia halted its space-tourism role in 2010. (It cited the need to devote its Soyuz capsules to ferrying ISS crew members after NASA ended its space-shuttle program.) Still, so-called space tourism remains on the map as companies like Virgin Galactic race to launch suborbital flights that skirt the edge of space and offer a taste of weightlessness. Virgin's ticket price: $200,000.

"Not all commercial space activities are about tourism," notes Launius. "Many are about communication, remote sensing, or other activities in which a profit may be made."

One thing that hasn't changed is the view from above. People may no longer stop to take in the video feed from spacecraft floating above Earth, but just listen to Gagarin's conversation with his ground control and you can feel the suspense and awe of seeing the planet from space.

No wonder a great window counts as a major creature comfort for the ISS crew. "The astronauts love to hang out in the station's cupola," with its panoramic views of Earth, says Barry. "I hear they moved an exercise bike there, and one guy likes to hang out and play his guitar."-www.shafaqna.com/English

Source: Nationalgeographic

SHAFAQNA (Shia International News Association) – A strange green space rock hailed as perhaps the first meteorite ever discovered from Mercury may be too old to have come from the solar system's innermost planet, some scientists say.

Last month, scientists announced that the green-hued meteorite NWA 7325 shares many chemical similarities with Mercury, suggesting it may be the first known visitor from the small, sun-scorched planet.

But NWA 7325's advanced age -- it's thought to be more than 4.5 billion years old -- casts some doubt on this interpretation, some scientists have stressed, citing the example of Earth's moon to help make their point.

"The moon began to crystallize 4.5 billion years ago, but we don't have any 4.5-billion-year-old meteorites from the moon, because all of those rocks would have been bashed to smithereens during the Late Heavy Bombardment that pockmarked the moon with craters between 4 to 3.8 billion years ago," meteorite expert Randy Korotev, of Washington University in St. Louis, said in a statement.

"The same thing would have happened on Mercury, so the question is, How did this rock survive for that long?" Korotev added. "There's no sign of it being brecciated, or busted up."

Still, Korotev doesn't rule out the possibility that NWA 7325, which was found in Morocco last year, is indeed from Mercury. Further tests could help researchers get a better sense of the meteorite's origins, he added.

A test with the potential to be particularly informative would assess NWA 7325's levels of "cosmogenic radionuclides," unstable atoms generated by exposure to cosmic radiation.

"If this stone had exceedingly high cosmogenic nuclides, that would be an argument for it coming from Mercury, because Mercury is so close to the sun," Korotev said.

While NWA 7325's exact provenance remains unclear at the moment, scientists do know something about its origins. The meteorite is an achondrite, a relatively rare type of space rock that comes from a planet or big asteroid -- something large that generated enough internal heat early in its history to melt partially, producing a metallic core surrounded by rock.

And researchers have a pretty good idea of where its green color comes from.

"I once analyzed bottles to see what made them blue or green," Korotev said. "The greenest bottle had 660 parts per million chromium, but some of the mineral components of NWA 7325 have 7,000 parts per million chromium. That's why it's green."-www.shafaqna.com/English

Source: Huffingtonpost

SHAFAQNA (Shia International News Association) – It keeps going ... and going ... and going ....

After cruising the “magnetic highway” that rings the very outskirts of the solar system, NASA's Voyager 1 spacecraft has entered a new and unexplored region of space, although it had yet to exit the solar system, NASA indicated.

"It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space," NASA's Jet Propulsion Lab said in a statement. "In December 2012, the Voyager science team reported that Voyager 1 is within a new region called ‘the magnetic highway’ where energetic particles changed dramatically. A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space, and that change of direction has not yet been observed."

The Voyager spacecraft was launched in 1977, and is far and away the most distant man-made object from the sun, at more than 11 billion miles away. A new study of cosmic rays and radiation posted online Wednesday in the peer-reviewed journal Geophysical Research Letters shows that the spacecraft has decisively left our corner of the sky, saying goodbye to the influence of the sun and the familiar eight planets that make up our cosmic neighborhood (sorry, Pluto).

“It’s outside the normal heliosphere, I would say that,” said Bill Webber, professor emeritus of astronomy at New Mexico State University in Las Cruces. “We’re in a new region. And everything we’re measuring is different and exciting.”

The heliosphere is a region of space dominated by the sun and its wind of energetic particles, and which is thought to be enclosed, bubble-like, in the surrounding interstellar medium of gas and dust that pervades the Milky Way galaxy.

According to the study, on Aug. 25, 2012, Voyager 1 measured drastic changes in radiation levels as it travelled the cold distant reaches of space. Anomalous cosmic rays, those that are trapped in the outer heliosphere, all but vanished, dropping to less than 1 percent of previous amounts. At the same time, galactic cosmic rays -- radiation from outside of the solar system -- spiked to levels not seen since Voyager’s launch, with intensities as much as twice previous levels.

“Within just a few days, the heliospheric intensity of trapped radiation decreased, and the cosmic ray intensity went up as you would expect if it exited the heliosphere,” Webber said. He calls this transition boundary the “heliocliff,” as in, "Voyager 1 just fell off the heliocliff."

That's the edge of our solar system, right? Mostly, Webber said.

As Voyager continues to boldly go where no man has gone before, scientists continue to debate just where it is. Whether Voyager 1 has reached interstellar space or entered a separate, undefined region beyond the solar system remains up for debate, Webber said.

In December, scientists said the craft was exploring an area at the far reaches of the solar system that they called “the magnetic highway,” the last stop before interstellar space.

They described the magnetic activity at that point in space as unlike anything seen before.

"The new region isn't what we expected, but we've come to expect the unexpected from Voyager," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena.-www.shafaqna.com/English

Source: Fox News

SHAFAQNA (Shia International News Association) – 15,000-Pixel-Wide Panorama of Mt. Sharp

This mosaic of images from the Mast Camera (Mastcam) on NASA's Mars rover Curiosity shows Mount Sharp in raw color as recorded by the camera (see below for full image). Raw color shows the scene's colors as they would look in a typical smart-phone camera photo, before any adjustment.

Mount Sharp, also called Aeolis Mons, is a layered mound in the center of Mars' Gale Crater, rising more than 3 miles (5 kilometers) above the crater floor, where Curiosity has been working since the rover's landing in August 2012. Lower slopes of Mount Sharp are the major destination for the mission, though the rover will first spend many more weeks around a location called "Yellowknife Bay," where it has found evidence of a past environment favorable for microbial life.

This mosaic was assembled from dozens of images from the 100-millimeter-focal-length telephoto lens camera mounted on the right side of the Mastcam instrument. The component images were taken during the 45th Martian day, or sol, of Curiosity's mission on Mars (Sept. 20, 2012). The sky has been filled out by extrapolating color and brightness information from the portions of the sky that were captured in images of the terrain.

A white-balanced version of the mosaic is available at PIA16768. White balancing makes the sky look overly blue, but shows the terrain as if under Earth-like lighting. Curiosity's Mastcam was built and is operated by Malin Space Science Systems, San Diego.-www.shafaqna.com/English

Source: Weird

SHAFAQNA (Shia International News Association) – It was dark and chilly in Austin on Sunday, March 10th, the night that NASA planned to break the Guinness World Record for "largest outdoor astronomy lesson." The cold front had cleared the clouds, leaving the stars bright and stark in the sky, and the 526 space geeks in NASA ball caps and T-shirts didn’t mind the temperature – they were happy to participate, even though the talk was just a basic demonstration on light and color. Some even lugged their own telescopes.

At 8:35PM, Dr. Frank Summers, the master of ceremonies and a Hubble astrophysicist, stopped abruptly to make an announcement. "Those of you with smartphones," he said, with a triumphant pause, "You can tweet that we have just finished the world’s largest outdoor astronomy lesson!"

The world record attempt was just one hour out of NASA’s multi-day programming at South by Southwest Interactive, the infamous digital conference. Twitter hit its tipping point here, the legend goes, and so many big brands have started to make the trek. This is NASA’s first year among them, part of a larger effort to cultivate a "hipper, more accessible" image and reach new audiences. But it may be missing the mark on both counts. NASA’s social strategy draws some people in, but there are signs that things need to change — much like NASA itself.

Arousing Curiosity

NASA has been using social media since 2008, more than a year before Mike Massimino became the first astronaut to tweet from space. NASA has 487 social media accounts, including 161 Twitter accounts and 36 YouTube channels. The rest are spread across eight other platforms including Facebook, Ustream, and Google+. The agency has also hosted more than 50 "tweetups," or "space socials," for which online fans have traveled from as far as Spain to watch a launch or spend a few hours with NASA engineers.

But nobody outside the space community really noticed NASA’s social media presence until August, when the Mars Curiosity landing became a case study for the art of viral marketing.

Historically, NASA has carefully curated its image. "NASA in the Apollo era was completely buttoned down," said Dr. Phil Plait, who writes the "Bad Astronomy" column at Slate. "NASA maniacally controlled the astronauts, trained them on how to talk to the public, how to do press conferences, how to dress, how to act, how to speak. Clearly, things are different now."

The Curiosity rover takes selfies, makes GIFs, and uses the hashtag #PewPew

These days, NASA’s communiques are more Bill Nye the Science Guy than "giant leap for mankind," a shift that accelerated after the success of @MarsCuriosity. The Curiosity rover is chatty and irreverent, the cool high school science teacher kind of nerd. It takes selfies, makes GIFs, and uses the hashtag #PewPew when it tweets about its laser.

@MarsCuriosity’s fresh voice, backed by a dramatic animation, "Seven Minutes of Terror," surprised and delighted the public out of its usual apathy toward unmanned space missions. Today, the rover has 1.3 million Twitter followers, making it about three percent as popular as Lady Gaga, about half as popular as an NBA star, and roughly on par with Newark mayor and super-tweeter Cory Booker. Its unofficial parody alter-ego, @SarcasticRover, has 108,254 followers.

Curiosity’s Twitter presence is controlled by three people: social media manager Veronica McGregor and social media specialists Stephanie Smith and Courtney O’Connor. Curiosity is the biggest rover NASA has ever sent to Mars, hence its brash personality. Its sense of humor comes from the three intelligent, funny, and outgoing women who write its tweets and call themselves "the hive mind." "We’ll try to bounce them off each other," O’Connor said. "If one of us laughs, then we know we’ve got a good tweet on our hands."

Social science

Levity plays well on social media, but critics say it undermines NASA’s reputation. When the co-anchor of NASA’s in-house TV show started using slang in his blog posts in 2009, fans took offense. "If the younger generation isn’t interested in NASA, I doubt a presenter saying ‘hai’ all the time is going to change that," wrote science blogger Ian O’Neill.

But after the success of @MarsCuriosity, NASA seems to be sidelining its hard-earned reputation as a bastion of science and innovation. Instead, it’s catering to the Twitter demographic with glibness and gimmicks.

Science writer Graham Templeton recently reflected on @MarsCuriosity’s decision to tweet its first blurry picture, a test shot of its own wheel, instead of waiting a day so it could capture an inspiring sunset. "NASA used to be in the business of awe," he said. "Every step away from that has been a mistake."

The medium is the message

NASA’s shift in tone coincides with the overall rise of social media, but it also happened around the same time budget cuts ended plans for human space flight in the near future. Hardcore science fans can get excited about probes and rovers, but it’s difficult to keep the general public interested unless you’re talking about aliens or astronauts – and that’s what NASA is trying to do with social media.

Stephanie Schierholz, who now works for Raytheon, was the first person to take charge of @NASA. "I was a public affairs specialist, and all 15 of us were instructed by our boss that we had to figure out this social media thing," she told The Verge, referring to NASA Deputy Associate Administrator Bob Jacobs. "We definitely couldn’t have done it without his support. There were plenty of naysayers, plenty of people who thought we shouldn’t be wasting our time on Twitter."’

Schierholz scheduled calendar appointments three times a day to remind herself to check Twitter. There were only a couple thousand followers, so it was relatively low-risk. When she noticed that people were asking NASA a lot of questions, she started replying. Seeing the thrilled reactions was "where it actually got interesting," she said.

NASA hasn’t quite figured out how to talk about rocket science to the average person

"People have an overall fondness for NASA in general. The majority of people think NASA’s cool, it has cachet," she said. "But if you ask them any in-depth level question about what NASA is doing, they don’t know how long the space shuttle has been operating, they don’t know when the last moon mission was. Social media connects the public to the cool people doing cool things at NASA."

However, NASA hasn’t quite figured out the right way to talk about rocket science to the average person.

NASA rightly points out that its social media communiques, while cute, are still dense with facts. But esoteric science jargon wrapped in pop culture references really only appeals to the kind of people who already love NASA. To the drive-by Twitter follower, most of @MarsCuriosity’s tweets are gibberish.

To bridge that gap, NASA would have to do something much tougher than cracking jokes or even explaining what a RAD instrument is in 140 characters. Most Twitter users don’t understand why NASA is taking radiation readings on Mars in the first place, or why anyone would care. @MarsCuriosity, for all its entertainment value, doesn’t answer those questions.

It’s also unclear how much the agency’s new fans are worth. When Justin Bieber retweeted @NASA, the account gained 17,000 followers, mostly teenaged girls. That would be a nice new demographic for the space agency – if it weren’t for the more likely explanation that thousands of girls clicked on something Justin Bieber implied he liked.

Next phase

The space program has always been a target of budget hawks who say it’s a waste of taxpayer money to play around in space when there are more tangible problems on earth. As NASA cedes human space flight to private companies like SpaceX, it could become even harder to justify the roughly half of one percent of the US budget it receives.

Meanwhile, goofy hijinks like this "Gangnam Style" parody music video, produced by summer interns at NASA's Johnson Center and released on a NASA YouTube Channel, seem destined to end up on the Congressional floor as part of some politician’s rant.

NASA’s findings do benefit average Americans, seeding countless technologies that improve our lives: real-time GPS, more accurate weather data, invisible braces, scratch-resistant lenses, and so on. NASA could use its Twitter accounts to remind people where their satellite communications and memory foam mattresses came from – or at least point out how its current projects will eventually trickle down to earthlings.

A report by the National Research Council released in December concluded that NASA is underfunded and a bit lost, stretching its limited resources over too many projects because it lacks "a national consensus on strategic goals and objectives."

NASA's goofy hijinks seem destined to end up as part of some politician's rant

Perhaps that’s why NASA’s social media strategy, largely propelled by the medium’s instant feedback mechanism and a few savvy individuals, seems to lack an end game. Still, NASA’s charter includes a mandate to widely publicize its findings, and its audience wants it to be on social media. Keri Bean was a freshman at Texas A&M and a major space geek when she created a Facebook profile for Mars Exploration Rovers and designated it as her spouse. "My roommate was like, ‘if you love the Mars rover so much, why don’t you marry it?’ So I did." The profile quickly hit the 5,000-friend limit and was converted to an official fan page. Bean, now a meteorologist on the Curiosity mission, handed it over to NASA.

"Back when NASA was first starting up, a kid could write a letter and NASA would send them materials and send them information," said Laura Burns, a space geek who follows the agency on social media and also happens to work as a NASA contractor. "But I mean, how many ways can you reach more than a million people in one fell swoop? I think it’s pretty cool. But I’m kind of biased."-www.shfaqna.com/English

Source: The verge

SHAFAQNA (Shia International News Association) -- Scientists say the Magnitude 9.0 tremor on 11 March 2011 sent a ripple of sound through the atmosphere that was picked up by the Goce satellite.

Its super-sensitive instrumentation was able to detect the disturbance as it passed through the thin wisps of air still present 255km above the Earth.

It has long been recognised that major quakes will generate very low-frequency acoustic waves, or infrasound - a type of deep rumble at frequencies below those discernible to the human ear. But no spacecraft in orbit has had the capability to record them, until now.

"We've looked for this signal before with other satellites and haven't seen it, and I think that's because you need an incredibly fine instrument," said Dr Rune Floberghagen from the European Space Agency (Esa).

"Goce's accelerometers are about a hundred times more sensitive than any previous instrumentation and we detected the acoustic wave not once, but twice - passing through it over the Pacific and over Europe," the mission manager told BBC News.

Goce's prime purpose is to map very subtle differences in the pull of gravity across the surface of the Earth caused by the uneven distribution of mass within the planet.

These variations produce almost imperceptible changes in the velocity of the satellite as it flies overhead and which it records with those high-precision accelerometers.

This gravity signal is very weak, however, and that means Goce must fly incredibly low to sense it - so low, in fact, that it actually drags through the top of the atmosphere.

It is these special circumstances that put the satellite in a position to detect the infrasonic disturbance on 11 March 2011.

The acoustic waves perturbed the density of air molecules and changed their speed. It was the faintest of winds at an altitude of 255km, but strong enough to be registered by Goce.

The Esa spacecraft encountered the signal as it passed over the Pacific some 30 minutes after the onset of the M9.0 event, and then again 25 minutes later as it moved across Europe.

Because of the way the accelerometers are arranged in Goce, it was possible to reconstruct the detection in three dimensions and so confidently trace the infrasound back to its source - the earthquake.

"If you have a small ripple in density, it would be hard to conclude beyond any reasonable doubt that this was due to the earthquake," explained Dr Floberghagen. "But the fact that we have a very significant density perturbation, with the shape predicted by all the acoustic models, and the fact that we picked it up again on the other side of the Earth where you would expect to find it - that's perfect."

Scientists can already study earthquakes from space, in particular through the use of radar to map the deformation of the ground that results when faults rupture. But it remains to be seen how useful an acoustic sensor placed in a low-Earth orbit might be.

Tohoku was an exceptional event and this may explain why Goce, on this occasion, was able to pick it up.

Buoyed by their success, however, scientists on the mission are checking through the satellite's data to see if an infrasonic signal was also recorded when an asteroid entered the atmosphere over the Russian city of Chelyabinsk last month. The entry's infrasound signature was certainly evident to listening stations on the ground.

"Ever since we've flown this type of instrument - accelerometers - in space, people have been looking for the acoustic beat from earthquakes, because that could be used to understand the way tremors propagate not only through the Earth but through the Earth environment.

"We'll see; time will tell. But just the idea of an acoustic sensor in space is pretty cool," Dr Floberghagen told BBC News.

Goce itself is running low on fuel and is nearing the end of its mission.

Esa will lower its orbit in June to below 230km to try to obtain even finer detail on Earth's gravity field. The agency is then expected to command the satellite to come out of the sky and fall back to Earth in November.

www.shafaqna.com/English

SHAFAQNA (Shia International News Association) – A small Russian spacecraft in orbit appears to have been struck by remnants of a destroyed Chinese satellite. It’s just the second time in history that an active spacecraft has collided with an artificial object while in orbit.

The collision took place between Russia’s Ball Lens in the Space (BLITS) spacecraft and China’s Fengyun 1C satellite, according to the Center for Space Standards & Innovation (CSSI), based in Colorado Springs, Colorado. The collision appears to have occurred on January 22, although it took over a month to determine what exactly hit the craft.

The Chinese material is considered to be “space junk” left over from when the Chinese craft was destroyed in a 2007 anti-satellite demonstration when the Fengyun 1C was intentionally demolished after exceeding its service life. The debris has posed a threat to satellites and crewed spacecraft ever since, according to Space.com.

China’s anti-satellite defense program aims at destroying satellites in space with the help of a missile, if needed. “It is necessary for China to have the ability to strike US satellites. This deterrent can provide strategic protection to Chinese satellites and the whole country's national security," said a January editorial in China’s state-run Global Times. China has since then conducted another test, in 2010.

The space collision involving BLITS was first reported on February 4 by Russian scientists Vasiliy Yurasov and Andrew Nazarenko, of the Institute for Precision Instrument Engineering (IPIE) in Moscow. They reported a “significant change” in the orbit of the BLITS satellite to CSSI, as well as changes in the spacecraft’s spin velocity and altitude.

"They requested help in determining whether these changes might have been the result of a collision with another object in orbit," CSSI's technical program manager, T.S. Kelso, explained in a blog post on the Analytical Graphics, Inc. website, which analyzed the crash.-www.shfaqna.com/English

Source: RT

SHAFAQNA (Shia International News Association) -- After a technical hiccup, SpaceX's Dragon cargo capsule reached the International Space Station on Sunday.

The unmanned Dragon is carrying more than 1,200 pounds of supplies for the crew and the crew's experiments. The station's robotic arm captured the Dragon at 5:31 a.m. ET, NASA said.

The arm will guide the supply capsule into the station, and the Dragon is expected to berth at about 9:40 a.m.

The Dragon suffered a temporary glitch with its thrusters after it launched into orbit Friday from Cape Canaveral, Florida.

Shortly after the capsule separated from its rocket, SpaceX determined three of the capsule's four thruster pods -- which it would use to reach the station -- weren't operating. The problem appeared to be "an issue with a propellant valve," SpaceX spokeswoman Christina Ra said.

The company said the problem appeared to be fixed by Friday afternoon.

"Thruster pods one through four are now operating nominally. Preparing to raise orbit. All systems green," SpaceX CEO Elon Muskposted on Twitter Friday afternoon.

The supply mission is SpaceX's second of a planned 12 under a contract with NASA.

SpaceX became the first private company to deliver supplies to the station on NASA's behalf in October.

NASA chose SpaceX's Falcon 9 launch vehicle and the Dragon spacecraft to resupply the space station in 2008. The space agency has retired its fleet of space shuttles and plans to turn much of its focus toward exploring deep into the solar system.

www.shafaqna.com/English

SHAFAQNA (Shia International News Association) –For the first time ever, scientists have been able to measure the precise spin rate of a 'supermassive black hole'. The findings will provide some clue as to how some of the most mysterious objects in our universe began to form.

The black hole is located in the NGC 1365 galaxy, located 56 million light years away from us, and  two million times the mass of the Sun.

By its very nature, a black hole is an object so dense that its gravity is strong enough to absorb the space around it. But in the process, as the incoming objects create friction and heat up, it emits x-rays.

It is these x-rays that astronomers measured, using the Nuclear Spectroscopic Telescope Array (NuSTAR), launched by NASA last year, and the European Space Agency's XMM-Newton.

"We can trace matter as it swirls into a black hole using X-rays emitted from regions very close to the black hole," said the co-author of the new study just published in Nature magazine, Fiona Harrison of the California Institute of Technology in Pasadena.

"The radiation we see is warped and distorted by the motions of particles and the black hole's incredibly strong gravity."

It turns out the supermassive black hole is rotating at approximately 84 percent of the speed allowed by the Theory of Relativity – close to the speed of light.

But the data has thrown up even more interesting discoveries.

"The black hole's spin is a memory, a record, of the past history of the galaxy as a whole," said the study's lead author, Guido Risaliti of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and the Italian National Institute for Astrophysics.

Confirming that black holes move at such speed allows us to discover just how they were formed, from their original small size to giant status over billions of years.

If they had been produced by randomly pulling objects around them, it would not be able to develop such a fast, smooth rate of spin. So scientists are now sure that black holes expand evenly, through a process known as "ordered accretion", as gas and stars are gradually sucked into the hole.

The data will now be applied to other black holes, whose spin had tentatively been measured, but which was previously explained by alternative theories.

And since mass and spin are the only information an outsider can make about a black hole (since objects only travel one way into it) astronomers are coming close to understanding the phenomena, and can use them to study the Theory of Relativity (of which they are a perfect example) more closely.

"This is hugely important to the field of black hole science," summed up Lou Kaluzienski, a NuSTAR program scientist at NASA Headquarters.-www.shfaqna.com/English

Source:RT