Category Archives: Space

Deflecting Killer Asteroids Away From Earth

Deflecting Killer Asteroids Away From Earth: How We Could Do It | Asteroid 2005 YU55, Asteroids & Near-Earth Objects | Asteroid Impact & Mass Extinction | Space.com.

An illustration of how solar sails might help deflect the asteroid Apophis.
CREDIT: Olivier Boisard

A huge asteroid’s close approach to Earth tomorrow (Nov. 8) reinforces that we live in a cosmic shooting gallery, and we can’t just sit around waiting to get hit again, experts say.

Asteroid 2005 YU55, which is the size of an aircraft carrier, will zip within the moon’s orbit tomorrow, but it poses no danger of hitting us for the foreseeable future. Eventually, however, one of its big space rock cousins will barrel straight toward Earth, as asteroids have done millions of times throughout our planet’s history.

If we want to avoid going the way of the dinosaurs, which were wiped out by an asteroid strike 65 million years ago, we’re going to have to deflect a killer space rock someday, researchers say. Fortunately, we know how to do it.

“We have the capability — physically, technically — to protect the Earth from asteroid impacts,” said former astronaut Rusty Schweickart, chairman of the B612 Foundation, a group dedicated to predicting and preventing catastrophic asteroid strikes. “We are now able to very slightly and subtly reshape the solar system in order to enhance human survival.”

 

In fact, we have several different techniques at our disposal to nudge killer asteroids away from Earth. Here’s a brief rundown of the possible arrows in our planetary defense quiver. [The 7 Strangest Asteroids in the Solar System ]

 

The gravity tractor

If researchers detect a potentially dangerous space rock in plenty of time, the best option may be to send a robotic probe out to rendezvous and ride along with it.

The spacecraft’s modest gravity would exert a tug on the asteroid as the two cruise through space together. Over months or years, this “gravity tractor” method would pull the asteroid into a different, more benign orbit.

“You can get a very precise change in the orbit for the final part of the deflection using a technology of this kind,” Schweickart said in late September, during a presentation at Caltech in Pasadena, Calif., called “Moving an Asteroid.”

Humanity has already demonstrated the know-how to pull off such a mission. Multiple probes have met up with faraway asteroids in deep space, including NASA’s Dawn spacecraft, which is currently orbiting the huge space rock Vesta.

And in 2005, the Japanese Hayabusa probe even plucked some pieces off the asteroid Itokawa, sending them back to Earth for analysis.

Smash ’em up

We could also be more aggressive with our asteroid rendezvous craft, relying on brute force rather than a gentle gravitational tug. That is, we could simply slam a robotic probe into the threatening space rock to change its orbit.

We know how to do this, too. In 2005, for example, NASA sent an impactor barreling into the comet Tempel 1 to determine the icy object’s composition.

The impactor approach would not be as precise as the gravity tractor technique, Schweickart said, but it could still do the job.

There’s also the possibility of blowing the asteroid to smithereens with a nuclear weapon. The nuclear option could come into play if the dangerous space rock is too big to knock around with a kinetic impactor,  but it would likely be a weapon of last resort.

For one thing, blasting an asteroid to bits might end up doing more harm than good, said fellow presentation panelist Bill Nye, executive director of the Planetary Society.

“Momentum is conserved,” Nye said. “If you blow it up, then the whole giant spray of rocks is coming at the Earth instead of one.”

The politics involved in mobilizing use of a nuke could also be a cause for concern, Schweickart said. It will likely be hard enough to convince the world to mount any sort of asteroid-deflection mission in time, and adding nuclear missiles to the equation would make things much stickier.

“The potential use of nuclear explosives for deflection cannot currently be ruled out,” Schweickart said. “But it is an extremely low probability that they will be needed.”

Close Encounters of the Comet Kind: A Brief History
This image of Comet Tempel 1 was taken by NASA’s Deep Impact spacecraft on July 4, 2005, 67 seconds after a probe crashed into the comet.
CREDIT: NASA/JPL-Caltech/UMD

‘Mirror bees’ and foil wrap

While we’re pretty sure that gravity tractors and kinetic impactor probes would work, researchers are also looking into several other ideas. [Photos: Asteroids in Deep Space]

There’s the “mirror bee” concept, for example, which would launch a swarm of small, mirror-bearing spacecraft to a dangerous asteroid. These mini-probes would aim reflected sunlight at one spot on the space rock, heating it up so much that rock is vaporized, creating propulsive jets.

“The reaction of that gas or material being ejected from the asteroid would nudge it off-course,” Nye said.

The Planetary Society is helping fund research into mirror bees, Nye said. And while he said the concept isn’t yet ready for deployment or demonstration, he stressed that it’s not too far off, either.

“Maybe five years,” Nye told SPACE.com. “It’s not 30 years.”

Nye also floated another, more speculative idea. It might be possible to move an asteroid, he said, by wrapping it in reflective foil, like a giant baked potato. Photons from the sun might then nudge the space rock away from Earth, in much the same way they propel spacecraft equipped with solar sails.

“This might work, even if the thing is rotating,” Nye said. “OK, make no promises. But it’s something to invest in.”

Passing the intelligent life test

The biggest key to deflecting dangerous asteroids, researchers say, is detecting them with plenty of lead time to take appropriate action. We’d like to have a least a decade of notice, NASA scientists have said.

It’ll take awhile, after all, to mobilize and launch a deflection mission, and for that mission to do its job, especially if we go the gravity tractor route.

We need to make sure we can rise to the challenge when a big, threatening asteroid shows up on our radar, Schweickart and Nye said. Civilization’s very survival depends on it.

“If there is a community of intelligent life out in the universe … those intelligent beings will have already conquered this challenge,” Schweickart said. “Our entrance exam to that community of intelligent life is to pass this test.”

You can follow SPACE.com senior writer Mike Wall on Twitter: @michaeldwall. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

Big Asteroid to Cross Earth-Moon Orbit Tuesday 11/8/11

Big Asteroid to Cross Earth-Moon Orbit Tuesday | Wired Science | Wired.com.

    By Mark Brown, Wired UK

    An asteroid the size of an aircraft carrier is to soar past the Earth this week and, while NASA is certain that the space rock will not hit us, it will be our closest encounter with such a large chunk of rock in three decades.

    The 400-yard-wide asteroid is called 2005 YU55and at the point of closest approach it will graze our planet at 201,700 miles — about 10 percent closer to Earth than the Moon’s typical orbit.It is the “closest approach by an asteroid, that large, that we’ve known about in advance,” said principal investigator Lance Benner, from NASA’s Jet Propulsion Laboratory, in an educational announcement. This gives the space agency an unprecedented view of such a rare flyby — and it will take full advantage.

     

    NASA will track 2005 YU55 from the Deep Space Network at Goldstone California, and provide radar observations from the Arecibo Planetary Radar Facility in Puerto Rico. This should reveal a wealth of detail about the asteroid’s surface features, shape, and dimensions.

    The Arecibo radar telescope spotted the asteroid back in April 2010, and those observations provided the ghostly image of YU55, above. NASA hopes to get higher resolution snaps — with details as fine as two meters per pixel — this month.

    But what about amateur astronomers, will they be able to see it? “Absolutely,” said NASA astronomer and YU55 investigator Marina Brozovic in the announcement. “8 November is when it becomes a nighttime object and that is when you can see it.”

    “400 meters, I’d say, is a moderate size asteroid, but it’s still small and very far away. You’ll need at least a six-inch telescope in order to be able to observe it. You’ll see it buzzing really fast along the sky,” said Brozovic.

    “The pass’ track is especially favorable for western Europe and North America. But you’ll need to know exactly where and when to look,” wrote Kelly Beatty, senior contributing editor of Sky and Telescope magazine.

    The when is 23:28 UK time on 8 November. As for the where, Beatty wrote that, “the object will traverse the 70 degrees of sky eastward from Aquila to central Pegasus in just 10 hours, clipping along at seven arcseconds per second.” A star chart is available here.

    2005 YU55 is trapped in an orbit that frequently brings it back to Earth and our nearby neighboring planets — but the 2011 encounter with Earth is the closest this space rock has come for at least the last 200 years. NASA is certain that it will miss us, and “the gravitational influence of the asteroid will have no detectable effect on anything here on Earth, including our planet’s tides or tectonic plates.”

    Plus, “we have a very good idea about its orbit for the following hundred years and there is no chance of impact,” said Brozovic in the announcement. “We believe with these upcoming measurements at Arecibo and Goldstone we will remove this threat even further — probably for many centuries.”

    Updated: Nov. 7, 2011; 12:40 p.m. EST

    Image: NASA/Cornell/Arecibo/JPL-Caltech

    Asteroid Yu55 on course for close encounter with Earth

    Asteroid Yu55

    An image of asteroid Yu55, made from radar data taken in April 2010. Photograph: AP

    Astronomers around the world have readied their telescopes to catch a glimpse of a speeding ball of rock that will hurtle past the Earth on Tuesday night.

    Scientists say the asteroid, which is about a quarter of a mile wide, will pass inside the moon’s orbit and come within 198,000 miles (319,000km) of Earth at 23.28GMT. This is the closest a tracked object this size has come to the planet.

    Nasa calculates the 400-metre (1,312ft) wide asteroid, known as 2005 YU55, has roughly a one in 10m chance of hitting Earth in the next century. Were it to strike, the collision would unleash the equivalent of several thousand megatonnes of TNT.

    Even with clear skies the asteroid will not be visible to the naked eye, but professional and amateur astronomers will turn their telescopes on the rock to learn about its surface and chemical composition.

    Because the asteroid is approaching from the sun’s direction, there will be too much glare to observe the rock with optical or infra-red telescopes until the day of closest approach.

    “Most of the asteroids we see are so far out that we only get a small amount of information from the light reflected off them,” said Kevin Yates, at the Near Earth Objects Information Centre at the National Space Centre in Leicester. “Because this one is coming in so close we’ll be able to get more radar observations, which will give us a detailed surface map, and be able to get more of a chemical signature on the minerals it’s made up from.”

    The Arecibo telescope in Puerto Rico last year revealed the asteroid to be remarkably spherical while its surface is very dark, suggesting it is rich in carbon.

    Observatories at Nasa’s Goldstone Deep Space Communications Complex, in the Mojave desert of California, and at Green Bank, West Virginia, will join forces with Arecibo to watch the asteroid pass this week. Operators have called on scores of amateur astronomers to help with observations, using 10-12in telescopes with special filters.

    A similar flyby will not happen until 2028 when asteroid 2001 WN5 swings past the Earth at a distance of 143,000 miles.

    “We are finding a whole variety of unusual shapes out there and this asteroid is particularly spherical. If we can characterise them more and understand them more, then if we ever do have a threat from one, understanding the structure and the materials they’re made from would better equip us to divert one. It may be that there are materials on board that could be used as a fuel to drive an engine that would push it into a different orbit over 20 years,” Yates added.

    The asteroid is among the most ancient objects in the solar system, having formed from the dust and gas disc that surrounded the sun 4.5bn years ago. Though born in the asteroid belt between Mars and Jupiter the rock was pulled by gravity or nudged by collisions on to its new orbital course.

    “These are the building blocks left over from when the solar system formed and this particular carbonaceous asteroid is one of the most primitive types,” Yates said. “Understanding its chemical composition is like looking into the ingredients book to see how it was put together.”

    The asteroid will pass close to Venus in 2029, which will disturb its orbit to mean its next passage past Earth, in 2041, could be between 198,000 miles and nearly 30m miles from the planet. The close encounter after that will be with Mars in 2072.

     

     

    Space Junk Collision Could Set Off Catastrophic Chain Reaction, Disable Earth Communications

    Pentagon: A Space Junk Collision Could Set Off Catastrophic Chain Reaction, Disable Earth Communications | Popular Science.

     

    Orbital Debris The dots on this NASA-generated chart represent known pieces of large orbital debris. NASA

    Every now and again someone raises a stern warning about the amount of space junk orbiting Earth. Those warnings are usually met with general indifference, as very few of us own satellites or travel regularly to low Earth orbit. But the DoD’s assessment of the space junk problem finds that perhaps we should be paying attention: space junk has reached a critical tipping point that could result in a cataclysmic chain reaction that brings everyday life on Earth to a grinding halt.

    Our reliance on satellites goes beyond the obvious. We depend on them for television signals, the evening weather report, and to find our houses on Google Earth when we’re bored at work. But behind the scenes, they also inform our warfighting capabilities, keep track of the global shipping networks that keep our economies humming, and help us get to the places we need to get to via GPS.

    According to the DoD’s interim Space Posture Review, that could all come crashing down. Literally. Our satellites are sorely outnumbered by space debris, to the tune of 370,000 pieces of junk up there versus 1,100 satellites. That junk ranges from nuts and bolts lost during spacewalks to pieces of older satellites to whole satellites that no longer function, and it’s all whipping around the Earth at a rate of about 4.8 miles per second.

    The fear is that with so much junk already up there, a collision is numerically probable at some point. Two large pieces of junk colliding could theoretically send thousands more potential satellite killers into orbit, and those could in turn collide with other pieces of junk or with satellites, unleashing another swarm of debris. You get the idea.

    To give an idea of how quickly a chain reaction could get out hand consider this: in February of last year a defunct Russian satellite collided with a communications satellite, turning 2 orbiting craft into 1,500 pieces of junk. The Chinese missile test that obliterated a satellite in 2007 spawned 100 times more than that, scattering 150,000 pieces of debris.

    If a chain reaction got out of control up there, it could very quickly sever our communications, our GPS system (upon which the U.S. military heavily relies), and cripple the global economy (not to mention destroy the $250 billion space services industry), and whole orbits could be rendered unusable, potentially making some places on Earth technological dead zones.

    Epic Geomagnetic Storm Erupts

    Epic Geomagnetic Storm Erupts : Discovery News.

    Right this moment, there’s an epic magnetic battle raging above our heads.

    On Monday, at around 2 p.m. ET, a coronal mass ejection (CME) slammed into the Earth’s magnetosphere. According to NASA’s Space Weather Laboratory, the conditions were just right for the CME’s magnetic field to compress the Earth’s magnetosphere so much that, for a short time (between 3:06 p.m and 3:11 p.m. ET), energetic solar wind particles penetrated as deep as geosynchronous orbit — home to hundreds of communication satellites.

    ANALYSIS: Epic Aurora Caught Cross Country — Share YOUR photos of the aurora!

    Although the interactions between solar plasma and Earth’s magnetic field are often invisible, tonight is an exception. Vast aurorae are rippling through the atmosphere at very low latitudes.

    At time of writing, the US was being given a dazzling show as Spaceweather.com reports:

    Northern Lights have spilled across the Canadian border into the contiguous USA. Sighting reports have come from as far south as Arkansas, Wisconsin, Michigan, Tennessee, Missouri, Illinois, Nebraska, Kentucky, Indiana, Oklahoma, Kansas, Maryland, New York, Ohio and central California.

    Yes, central California! To see some of the auroral displays, the Universe Today has a few reader’s photos featured. My personal favorite is an earlier photograph taken in Norway.

    SCIENCE CHANNEL: VIDEO: Jupiter’s Storms

    Why is this happening? And why now?

    It is well known that the sun is building in activity toward “solar maximum” — the peak is predicted to occur by around 2013 — and we have witnessed some huge solar flares recently.

    Flaring activity and the eruption of CMEs are both symptomatic of the extreme magnetic stresses torturing the sun’s interior.

    So, we’ve just experienced a CME punch — solar plasma contained within the CME and solar wind have streamed into the magnetosphere. Usually these energetic particles would follow the magnetic field lines and be confined to the North and South Polar Regions, creating the familiar Aurora Borealis and Aurora Australis, respectively — as the solar particles rain down through the atmosphere, impacts with atmospheric gases cause the atmosphere to glow. But this time the conditions were just right that the powerful CME impact caused a geomagnetic storm to ripple across the globe, extending the aurorae.

    ANALYSIS: How Does the Sun Affect the Earth?

    Scientists are able to measure when a geomagnetic storm is underway by using the “Kp index.” This measurement is derived by measuring how much the horizontal component of the Earth’s magnetic field varies over a 3-hour period. Depending on the intensity of fluctuations, the Kp index is assigned values between 0 to 9. If the value hits 5, this means a geomagnetic storm is occurring and auroral displays can be expected.

    At its peak, the Kp index hit a “7” — a strong geomagnetic storm!

    Kp

    Apart from generating beautiful auroral displays at lower latitudes than would be expected, strong geomagnetic storms can have a sinister side. As energetic particles wash through our orbital neighborhood, vulnerable satellites can be damaged and huge electrical currents can be induced through the upper atmosphere, potentially overloading entire power grids.Watch movie online The Transporter Refueled (2015)

    SLIDE SHOW: Extreme Space Weather

    Last year, the much-publicized “zombiesat” was caused by a solar storm knocking out a satellite’s ability to communicate with Earth. Its brains were, quite literally, “fried.”

    And if you think it’s not possible for the sun to damage a power grid, think again. In 1989, Hydro-Québec power grid was knocked out by a geomagnetic storm caused by a CME hitting the Earth. Just before the grid was knocked out — leaving millions of customers without power for several hours — aurorae were spotted as far south as Texas.

    It is unlikely that the current geomagnetic storm will cause satellite harm or power grid mayhem, but as society becomes ever more dependent on delicate electronics and constant mains electricity, we become increasingly vulnerable to the awesome violence of solar eruptions.

    Space Weather Forecasters Get Closer to worthwhile predictions

    Space Weather Forecasters Get Serious – ScienceNOW.

     

    A new forecast model simulates the approach of a coronal mass ejection (boomerang of color) to Earth (green dot) that would trigger a solar storm.

    It took a while, but space physicists who predict immense balls of solar debris smashing into Earth have finally caught up with their brethren who forecast terrestrial weather. Rather than simply relying on rules of thumb, space weather forecasters have begun running a computer model that actually simulates the development of conditions between the sun and Earth. They’re following the lead of atmospheric weather forecasters, who have been using computer models since the 1960s. Warnings of when solar storms will strike Earth are already much improved.

    The better the warning of major solar storms, the better earthlings can prepare for the consequences, which can include electrically fried satellites, degraded GPS navigation, and widespread blackouts. The culprit is a magnetic bubble of tens of millions of tons of protons and the like blown off the sun at several million kilometers per hour. It might seem easy enough to keep track of something that big, but observation platforms between the sun and Earth are few and far between. And the choppy sea of magnetic fields and charged particles that the ejected bubbles plow through can slow and deflect the bubbles.

    Drawing on the typical behavior of previous bubbles, called coronal mass ejections (CMEs), forecasters at the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) in Boulder, Colorado, had been predicting the arrival of CMEs at Earth with an accuracy of plus or minus 15 hours. They would usually say which day a storm might strike but not much more.

    The new forecasting system, developed by a consortium of 11 institutions led by Boston University and refined by SWPC, has been in routine operation since the beginning of the month. It includes a computer simulation that calculates how a particular CME will move out from the sun and through the evolving interplanetary “weather” on its way to Earth. One model component handles a particular CME moving from the sun’s surface into interplanetary space, and another simulates its progress in three dimensions out to Earth’s orbit and beyond.

    The new model components allowed SWPC forecasters to shrink their timing error from 15 hours to 6 hours. “From a space weather standpoint, that’s a pretty big deal,” says space physicist Daniel Baker of the University of Colorado, Boulder. “The forecast model gives some confidence in predictions” for the vicinity of Earth.

    Not that forecasts couldn’t use a lot more improvement. For instance, there’s no sign as yet that the advent of physics-based forecasting will improve predictions of the power of a solar storm inside Earth’s magnetic cocoon where it matters, notes forecaster Douglas Biesecker of SWPC. To anticipate that, researchers will have to understand much more about the innards of CMEs.

     

    NASA satellite fiery demise

    Heads up! NASA satellite descends toward fiery doom | The Space Shot – CNET News.

    A chart showing the latest predicted entry point for the Upper Atmosphere Research Satellite, based on data from U.S. Strategic Command. Because of uncertainty about the satellite’s behavior as it approaches the discernible atmosphere, the timing of the re-entry could change by several hours either way.

    (Credit: William Harwood/MacDoppler Pro)

    “As of 10:30 a.m. EDT on Sept. 23, 2011, the orbit of UARS was 100 miles by 105 miles (160 km by 170 km),” NASA said in a brief update. “Re-entry is expected late Friday, Sept. 23, or early Saturday, Sept. 24, Eastern Daylight Time. Solar activity is no longer the major factor in the satellite’s rate of descent. The satellite’s orientation or configuration apparently has changed, and that is now slowing its descent.

    Related story
    Track NASA’s crashing satellite to avoid getting hit by space junk

    “There is a low probability any debris that survives re-entry will land in the United States, but the possibility cannot be discounted because of this changing rate of descent. It is still too early to predict the time and location of re-entry with any certainty, but predictions will become more refined in the next 12 to 18 hours.”

    A subsequent update from U.S. Strategic Command, which operates a global radar network used to monitor more than 20,000 objects in low-Earth orbit, predicted the satellite would re-enter sometime around 11:34 p.m. EDT Friday as the spacecraft flies over the southern Indian Ocean. But the prediction was uncertain by several hours and at orbital velocities of 5 miles per second, just 10-minutes of uncertainty translates into 3,000 miles of uncertainty in position.

    For comparison, some 42.5 tons of wreckage from the shuttle Columbia hit the ground in a footprint stretching from central Texas to Louisiana when the orbiter broke apart during re-entry in 2003. No one on the ground was injured and no significant property damage was reported.

    Tracking data is expected to improve as the day wears on, and subsequent updates should be more precise.

    The centerpiece of a $750 million mission, the Upper Atmosphere Research satellite was launched from the shuttle Discovery in September 1991. The solar-powered satellite studied a wide variety of atmospheric phenomena, including the depletion of Earth’s ozone layer 15 to 30 miles up.

    The long-lived satellite was decommissioned in 2005 and one side of its orbit was lowered using the last of its fuel to hasten re-entry and minimize the chances of orbital collisions that could produce even more orbital debris. No more fuel is available for maneuvering and the satellite’s re-entry will be “uncontrolled.”

    Nick Johnson, chief scientist with NASA’s Orbital Debris Program at the Johnson Space Center in Houston, told reporters last week he expects most of the satellite to burn up as it slams into the dense lower atmosphere at more than 17,000 mph. But computer software used to analyze possible re-entry outcomes predicts 26 pieces of debris will survive to impact the surface in a 500-mile-long down-range footprint.

    “We looked at those 26 pieces and how big they are and we’ve looked at the fact they can hit anywhere in the world between 57 north and 57 south and we looked at what the population density of the world is,” he said. “Numerically, it comes out to a chance of 1-in-3,200 that one person anywhere in the world might be struck by a piece of debris. Those are obviously very, very low odds that anybody’s going to be impacted by this debris.”

    For comparison, some 42.5 tons of wreckage from the shuttle Columbia hit the ground in a footprint stretching from central Texas to Louisiana when the orbiter broke apart during re-entry in 2003. No one on the ground was injured and no significant property damage was reported.

    NASA finds 90 percent of largest near-Earth asteroids

    NASA finds 90 percent of largest near-Earth asteroids; finds fewer medium-sized asteroids – The Washington Post.

    LOS ANGELES — If you’re worried about a killer asteroid wiping out Earth, NASA has some good news.

    The space agency said Thursday it has identified more than 90 percent of giant near-Earth asteroids, including ones as big as the one thought to have killed the dinosaurs eons ago. None poses a danger to the planet in the next several centuries.

    Comments

    (no/Associated Press) – In this undated artist’s rendition released Thursday Sept. 29,2011 by NASA/Jet Propulsion Laboratory, showing WISE, (Wide-field Infrared Survey Explorer), NASA on Thursday Sept. 29,2011 said its sky-mapping spacecraft called WISE has discovered 911 of 981 of the largest asteroids and has found more than 90 percent of the biggest asteroids that might pose a threat to Earth.

    “We know now where most of them are and where most of them are going. That really has reduced our risk” of an impact, said Amy Mainzer of the NASA Jet Propulsion Laboratory.

    NASA researchers also downgraded their estimate of the number of medium-sized asteroids, saying there are 44 percent fewer than previously believed. The downside is that scientists have yet to find many of these mid-sized asteroids, which could destroy a metropolitan city.

    “Fewer does not mean none,” Mainzer said. “There are still tens of thousands out there that are left to find.”

    The updated census comes from data from NASA’s sky-mapping spacecraft named Wide-field Infrared Survey Explorer, or WISE, which launched in 2009 to seek out near-Earth objects, galaxies, stars and other cosmic targets.

    Unlike previous sky surveys, WISE has sensitive instruments that can pick out both dark and light objects, allowing it to get the most accurate count yet of near-Earth asteroids. The spacecraft takes a small sample of asteroids of varying sizes and then estimates how large the population would be.

    For the largest asteroids — bigger than 3,300 feet across — NASA said 911 of the 981 thought to exist have been found. None poses a threat to Earth in the near future, the space agency said.

    Previous estimates put the number of medium-sized asteroids at 35,000, but WISE data indicate there are about 19,500 between 330 and 3,300 feet wide. Only about 5,200 have been found and scientists said there is still a lot of work left to identify the potentially hazardous ones.

    Results were published in the Astrophysical Journal.

    WISE is not equipped to detect the more than a million smallest asteroids that could cause damage if they impact Earth. The spacecraft recently ran out of coolant and is currently in hibernation.

    By locating most of the giant asteroids, NASA has fulfilled a goal set by Congress in 1998. More recently, the space agency has been asked to find 90 percent of asteroids that are at least 460 feet in diameter — slightly smaller than the Superdome in New Orleans — by 2020.

    Don Yeomans, who heads NASA’s Near-Earth Object Program Office, said that goal is about 35 percent complete.

    Huge Sun Storm Should Super-Charge Northern Lights

    Huge Sun Storm Should Super-Charge Northern Lights Tonight | Solar Storms & Northern Lights | The Sun & Space Weather | Space.com.

    Sunspot 1302 has already produced two X-class flares.
    Sunspot 1302 has already produced two X-flares (X1.4 on Sept. 22nd and X1.9 on Sept. 24th). Each of the dark cores in this image from SDO is larger than Earth, and the entire active region stretches more than 100,000 km from end to end. The sunspot’s magnetic field is currently crackling with sub-X-class flares that could grow into larger eruptions as the sunspot continues to turn toward Earth.
    CREDIT: NASA/SDO/HMI

    Particles that were blasted from the sun by a huge eruption over the weekend have reached Earth, causing geomagnetic storms on our planet, which will likely trigger a stunning northern lights show for some lucky skywatchers.

    The particles reached at Earth at 8:37 a.m. EDT (1237 GMT) today (Sept. 26), kicking off moderate geomagnetic storms at lower latitudes and more serious storms closer to the Earth’s poles, according to the U.S. National Oceanic and Atmospheric Administration (NOAA). These storms can disrupt GPS signals, radio communications and power grids, but no such effects have yet been reported, NOAA officials said.

    The storms should also give skywatchers in select locations a treat, creating dazzling auroras (phenomena also known as the northern and southern lights). [Photos: Auroras Dazzle Northern Observers]

     

    “Aurora watchers in Asia and Europe are most favorably positioned for this event, though it may persist long enough for viewers in North America,” officials with NOAA’s Space Weather Prediction Center (SWPC) wrote in an update today.

    A powerful solar eruption

    The sun unleashed a powerful solar flare and an event known as a coronal mas ejection (CME) on Saturday (Sept. 24). CMEs are massive clouds of solar plasma that can streak through space at 3 million miles per hour (5 million kilometers per hour) or more.

    Luckily, this CME delivered a glancing blow. If it had hit Earth directly, the geomagnetic storms — and, possibly, the damage — could have been more serious. But we’re not out of the woods yet, SWPC officials said.

     

    The storm erupted from a region known as sunspot 1302. Sunspots are temporary dark patches on the solar surface caused by intense magnetic activity. The area around sunspot 1302 may be brewing up more trouble. [Photos: Sunspots on Earth’s Closest Star]

    “Region 1302 remains capable of producing more activity and will be in a favorable position for that activity to have impacts on Earth for the next 3-5 days,” SWPC officials said.

    For now, however, the biggest effect of the geomagnetic storms may be the auroras, so skywatchers in favorable locations should look up when they get the chance.

    People in the mid- to high-latitudes should be alert for auroras after nightfall. The best hours to spot the northern and southern lights tend to be around local midnight, according to the website Spaceweather.com.

    Sun ramping up

    Sunspot 1302 has been particularly active lately, spouting off multiple X-class fares — the most poweful type — over the last few days. And that restlessness is part of a larger pattern, experts say.

    Sunspot 1302 poses a continued threat for X-class solar flares.
    Sunspot 1302 poses a continued threat for X-class solar flares.
    CREDIT: SDO/HMI

    Solar activity has been ramping up over the last few months as the sun has roused itself from an extended quiescent phase in its 11-year cycle of activity.

    Just last month, for example, the sun let loose with an X6.9 solar flare, which was the most powerful solar storm since December 2006, NASA scientists said.

    And the storms should keep coming over the next few years. Scientists expect activity in the current cycle — known as Solar Cycle 24 — to peak around 2013.

    Satellite problem causes phone and Internet outage

    Satellite problem causes phone and Internet outage – North – CBC News.

    Posted: Oct 6, 2011 9:56 AM CT

    Last Updated: Oct 6, 2011 10:15 AM CT

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    A malfunctioning satellite is affecting long distance telephone and Internet service in communities across the north.

    Northwestel said all communities across Nunavut, N.W.T. and Yukon that receive their long distance calling and data service via satellite are affected by the outage, which began at about 6:30 a.m. ET.

    People in Iqaluit are reporting they are without cell phone service and long-distance calling, bank machines and debit-card machines. At least one bank in the city has not opened today as a result. Flights are also being delayed.

    The service disruption appears to be due to problems Telesat is having with its Anik F2 satellite.

    At the present time, the satellite is pointing in the wrong direction, away from the Earth.

    Telesat is working to regain proper Earth lock, which may take 12 to 18 hours.

    'Old Faithful' Sunspot to Fire Off More Flares

    ‘Old Faithful’ Sunspot to Fire Off More Flares, Scientists Say | Solar Flares & Coronal Mass Ejections | The Sun & Space Weather | Space.com.

    Sunspot 1283 Storms
    A giant plume of ionized gas called plasma (to the right) leaps off the sun from sunspot 1283 in this photo snapped by NASA’s Solar Dynamics Observatory. This sunspot spouted four solar flares and three coronal mass ejections from Sept. 6-8, 2011.
    CREDIT: NASA/SDO/AIA

    An active region of the sun that blasted out powerful solar storms four days in a row last week likely isn’t done yet, scientists say.

    Officially, the flare-spouting region is called sunspot 1283. But space weather experts have dubbed it “Old Faithful,” after the famous geyser in the United States’ Yellowstone National Park that goes off like clockwork. And the solar Old Faithful should erupt again before it dissipates, researchers said.

    “It still has a fair amount of complexity,” said solar physicist C. Alex Young of NASA’s Goddard Space Flight Center in Greenbelt, Md. “So we still have a pretty good chance of seeing some more stuff from this one.” [Photos: Sunspots on Earth’s Closest Star]

     

    An active sunspot

    Sunspots are temporary dark patches on the solar surface caused by intense magnetic activity. Some last for hours before disappearing; others linger for days, weeks or even months.

    Powerful solar storms often erupt from sunspots. These include radiation-flinging solar flares and phenomena known as coronal mass ejections (CMEs) — massive clouds of solar plasma that can streak through space at up to 3 million mph (5 million kph).

    From Sept. 5-8, sunspot 1283 produced four big flares and three CMEs. Two of the flares were X-class events and two were M-class flares. (Strong solar flares are classified according to a three-tiered system: X-class are the most powerful, M-class are of medium strength and C-class are the weakest.)

    While the rapid motion previously observed in sunspot 1283 seems to have died down a bit, Young said, the sunspot looks poised to erupt again sometime soon.

    “There’s a good probability that we’re still going to see at least another M-class flare, possibly another X-class flare,” Young told SPACE.com.

    It’s not uncommon for sunspots to pop off a number of powerful flares in quick succession the way 1283 has done, he added. That seems to be the natural order of things.

    “When you see one big flare, your chances of seeing another one are pretty good,” Young said.

    A photo of a sunspot taken in May 2010, with Earth shown to scale. The image has been colorized for  aesthetic reasons. This image with 0.1 arcsecond resolution from the Swedish 1-m Solar  Telescope represents the limit of what is currently possible in te
    A photo of a sunspot taken in May 2010, with Earth shown to scale. The image has been colorized for aesthetic reasons. This image with 0.1 arcsecond resolution from the Swedish 1-m Solar Telescope represents the limit of what is currently possible in terms of spatial resolution.
    CREDIT: The Royal Swedish Academy of Sciences, V.M.J. Henriques (sunspot), NASA Apollo 17 (Earth)

    Learning more about solar storms

    Solar flares directed at Earth can cause temporary radio-communication blackouts. CMEs have even greater destructive potential; they can spawn geomagnetic storms that disrupt GPS signals, radio communications and power grids. [Sun’s Wrath: Worst Solar Storms in History]

    So researchers are working hard to better understand sun storms, with the aim of one day being able to predict them with a great deal of accuracy and a long lead time. But they’re not there yet.

    “We still have a long way to go to really have the kind of forecasting capabilities that we have with terrestrial weather,” Young said.

    That’s not to say scientists aren’t making progress. Indeed, they’ve learned a lot about solar eruptions lately, Young said. And the knowledge base will continue to grow, he added, as a fleet of sun-watching spacecraft beam home more and more observations of Earth’s star.

    “We’re really in a great time right now in terms of the data that we have,” Young said, citing the contributions of spacecraft such as NASA’s STEREO and Solar Dynamics Observatory, as well as SOHO, a collaboration between NASA and the European Space Agency. “It’s going to be pretty exciting, from a solar physics and a space weather point of view.”

    All of these eyes on the sun should be treated to quite a show over the next several years. Solar activity has been ramping up over the last few months as the sun works toward a maximum in its 11-year activity cycle.

    Scientists expect the peak of the current cycle, which is known as Solar Cycle 24, to come in 2013.