Guess who’s coming for dinner! Three astronauts from three different countries arrived at the International Space Station on Thursday, bringing the compliment of crewmembers on board the orbiting laboratory back to six. Mike Fossum (US), Sergei Volkov (Russian) and Satoshi Furukawa (Japan) were greeted by fellow Expedition 28 members Andrey Borisenko, Ron Garan, and Alexander Samokutyaev after their launch two days ago from the Baikonur Cosmodrome in Kazakhstan. The video includes some stunning views of the Soyuz edging closer to the ISS with the bright limb of Earth in the background, and glittering solar arrays bidding welcome to the crew.
Voyagers Find Giant Jacuzzi-like Bubbles at Edge of Solar System
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The barrier at the edge of our Solar System may not be the smooth shield that scientists once thought. The venerable Voyager spacecraft have detected a huge, turbulent sea of magnetic bubbles in the heliosheath — the interface between the heliosphere and interstellar space — similar to an actively bubbling Jacuzzi tub. At a briefing today, scientists said the finding is significant as “we now will have to change our view of how the Sun interacts with the Solar System,” said Arik Posner, Voyager program scientist at NASA Headquarters. But it also means that the “force field” that surrounds the entire Solar System may be letting in more harmful cosmic rays and energetic particles than previously thought.
Over 30 years into their mission, the Voyagers are still monitoring their environment and sending back data. In 2007, scientists noticed that Voyager 1 recorded dramatic dips and rises in the amount of electrons it encountered as it traveled through the heliosphere, the barrier that surrounds the entire Solar System and is created by the Sun’s magnetic field. Voyager 2 made similar observations of these charged particles in 2008.
Using a new computer model to analyze the data, scientists found the Sun’s distant magnetic field is likely made up of bubbles approximately 100 million miles (160 million kilometers) wide — “like long sausages,” said Merav Opher at the briefing, an astronomer at Boston University who is the lead author of a paper published in the Astrophysical Journal.
And the bubbles are moving around, with oscillations of plus or minus 10 to 20 km. “It is very bubbly as far as we can tell,” Jim Drake from the University of Maryland said at the press conference. “The entire thing is bubbly, like where the jets come out from a Jacuzzi.”
Opher said the bubbles, while not visible from Earth, cover a large portion of the sky at about 38 degrees latitude and as the solar winds “bumps” up against the heliopause, the bubbles fill up the entire region next to the heliopause.
Like Earth, our Sun has a magnetic field with a north pole and a south pole. The field lines are stretched outward, and as the sun rotates, the solar wind twists them into a spiral as they are carried outward.
The bubbles are created when magnetic field lines reorganize. The new model suggests the field lines are broken up into self-contained structures disconnected from the solar magnetic field.
These magnetic bubbles should act as electron traps, so the spacecraft would experience higher than normal electron bombardment as they traveled through the bubbles.
But the implications of this new finding, said Opher, is also that the heliosheath is very different from what scientists expected. She prefaced by saying that any earlier ideas about the region was only conjecture since no spacecraft has been there before. “We thought heliopause would be a smooth surface and shield us from intergalactic cosmic rays,” she said. “It is not a shield but more like a membrane that is a sea of bubbles.”
One argument would say the bubbles would seem to be a very porous shield, allowing lots of cosmic rays through the gaps. But another view would be that cosmic rays could get trapped inside the bubbles, making the bubbling froth a very good shield indeed.
However, the scientists are still working on figuring out exactly what these bubbles are. The Voyagers’ instruments, while still working fine, are being tested in this new region of space. “The magnetic instruments on Voyager were designed to measure magnetic fields, but they are right at very edge of what the instruments are capable of sensing,” said Drake. “The magnetic field is very weak. While trying to find out what these magnetic bubbles are, we haven’t reached that moment where we say, ‘yes, that is it.’ We’d like to be able to pin it down much better.”
This video from NASA’s Goddard Spaceflight Center helps to visually explain the new findings:
Sources: NASA press conference, NASA’s Sun/Earth briefing materials, press release, more videos and visuals can be found at this Goddard webpage
You can follow Universe Today senior editor Nancy Atkinson on Twitter: @Nancy_A. Follow Universe Today for the latest space and astronomy news on Twitter @universetoday and on Facebook.
Mathematics Explain Dynamics of Superfluid
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At nearly the coldest temperature possible – mercury (with the aid of liquid helium) – forms a state called superconductivity. At the extreme, electrons flow unencumbered through what is known as a superfluid. But the hows and whys of superfluid behavior defied explanation. Until now…
When taken to within a few degrees of absolute zero on the Kelvin scale (minus 273 Celsius or minus 460 Fahrenheit), liquid helium-4 turns into the remarkable superfluid state. It swirls, it curls, and it’s lack of body has been baffling scientists for nearly a century. Now a team led by a University of Washington physicist, using the most powerful supercomputer available for open science, has cooked up a theoretical picture which explains the real-time behavior of superfluid. Just who is the responsible party here? Try subatomic particles called fermions.
Femions are a much a part of the natural equation as electrons, protons and neutrons… just as superfluids are part of neutron stars. Rotating between one and 1,000 times a second, neutron stars – or pulsars – superfluid surface acts much differently than its counterpart here on Earth. As the speed increases, it forms a series of small vortices which group in a triangular pattern… which in turn forms a braid within the superfluid structure. “When you reach the correct speed, you’ll create one vortex in the middle,” Bulgac said. “And as you increase the speed, you will increase the number of vortices. But it always occurs in steps.”
Can science recreate it? Yes. Laboratory models utilizing a vacuum chamber and a laser beam to create a high-intensity electrical field have managed to chill a small sample, perhaps 1 million atoms, to temperatures near absolute zero. Then a “laser spoon” is employed to stir the superfluid fast enough to create vortices.
“In trying to understand the odd behavior, scientists have attempted to devise descriptive equations, such as ones they might use to describe the swirling action in a cup of coffee as it is stirred.” Bulgac said. “But to describe the action in a superfluid made of fermions, a nearly limitless number of equations is needed. Each describes what happens if just one variable – such as velocity, temperature or density – is changed. Because the variables are linked, if one changes others will change as well.”
One of the major challenges in formulating a mathematical hypothesis is the amount of computing power it would take to work through a problem with a number of variable changes that reached 1 trillion or more. So how did they do it? The team used the JaguarPF computer at Oak Ridge National Laboratory in Tennessee, one of the largest supercomputers in the world, for the equivalent of 70 million hours, which would require almost 8,000 years on a single-core personal computer (JaguarPF has nearly a quarter-million cores). Just try to cool that!
“This tells you the complexity of these calculations and how difficult this is,” Bulgac said. To make matters even more complex, the faster the superfluid is stirred causes it to lose its properties – but not as fast as hypothesized. “The work means that researchers can ‘to some extent’ study the properties of a neutron star using computer simulations.” Bulgac said. .”It also opens new directions of research in cold-atom physics.”
And more homework on our part.
Original Story Source: University of Washington.
Rosetta… Stoned Again
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About 163 million kilometers and three more years separate brave little ESA spacecraft – Rosetta – from comet Churyumov-Gerasimenko. But this seemingly huge distance isn’t stopping determined scientists from the Max Planck Institute for Solar System Research (MPS) in Germany. Their target might be a million times fainter than the faintest star we can see here on Earth with our eyes, but Rosetta has them covered. It has succeeded in imaging the distant comet and it’s right on target.
Using the onboard camera system OSIRIS, Rosetta took its snapshots during testing over the last couple of weeks in preparation for its three year hibernation period. These first images of the tiny, flying space stone only covered a few pixels; “But the pictures already give us a good idea of where we are headed”, says Dr. Holger Sierks from MPS, OSIRIS Lead Investigator. “In addition, they are a remarkable proof of the camera’s performance. We had not expected to be able to create first images from so far away”.
But now it’s going to be a long wait until Rosetta spots the stone again…
“We sent the command via NASA’s 70 m Deep Space Network station in Canberra, Australia, ensuring the signal was transmitted with enough power to reach Rosetta, which is now 549 million km from Earth,” said ESA’s Spacecraft Operations Manager Andrea Accomazzo. “We’ll monitor via ESA’s 35 m station at New Norcia in Australia for a few days to see if any problems occur, but we expect to receive no radio signal until 2014. Rosetta’s on her own now.”
Is there a handsome prince waiting in Rosetta’s future? Yes, in the form of a timer which will wake the slumbering spacecraft princess. When the moment arrives a signal will be transmitted back to Earth and mission control will then take command. Over a period of weeks Rosetta will “warm up” again in preparation for its landmark arrival at the distant, icy space stone. “Hibernation is a necessary step to reach the final target.” says Ferri. “We are now looking forward to 2014, when Rosetta becomes the first spacecraft to track the life of a comet as it arcs in toward the Sun.”
Rosetta? Rock on!
Original Story Sources: Max Planck Institute for Solar System Research and ESA Space Science.
Zoom into the Epic Images of Endeavour Docked to the ISS
Credit: NASA
Are you enjoying the historic images of space shuttle Endeavour docked to the ISS? Here’s a wonderful new way to experience them. John Williams of Terrazoom and StarryCritters has created an amazing “zoomable” slide show of these images, which allows viewers to quickly zoom into whatever part of the picture you want to see close up. Want to take a good look at Endeavour’s heat tiles or examine a module of the ISS? Just choose a picture and slide the scale (between the plus and minus sign) at the bottom of the application to zoom in.
Thanks to John for sharing his “Zoomify” technology with Universe Today!
See the slideshow on Terrazoom for the option for a full screen version.
Continue reading “Zoom into the Epic Images of Endeavour Docked to the ISS”
New VLT Survey Telescope Opens Wide Eyes to the Universe
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There’s a new telescope at the Paranal Observatory in Chile and what big eyes it has! The VLT Survey Telescope (VST) is a wide-field survey telescope with a field of view twice as broad as the full Moon, enabling new, spectacular views of the cosmos. It is the largest telescope in the world designed to exclusively survey the sky in visible light. Over the next few years the VST and its camera OmegaCAM will make several very detailed surveys of the southern sky.
The first image released from these new eyes on the Universe is a spectacular view star-forming region Messier 17, also known as the Omega Nebula or the Swan Nebula, shown above. The VST field of view is so large that the entire nebula, including its fainter outer parts, is captured — and retains its superb sharpness across the entire image.
The second image is the globular star cluster Omega Centauri. This is the largest globular cluster in the sky, but the very wide field of view of VST and OmegaCAM allows even the faint outer regions to be seen clearly. This view includes about 300,000 stars.
Here’s a look at the new telescope:
Below is a timelapse sequences of the VST enclosure at night:
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Comet Elenin: Just Passing By
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It starts out innocently enough: a small speck against a field of background stars, barely noticeable in the image data. But… it’s a speck that wasn’t there before. Subsequent images confirm its existence – there’s something out there. Something bright, something large, and it’s moving through our solar system very quickly. The faint blur indicates that it’s a comet, an icy visitor from the outermost reaches of the solar system. And it’s headed straight toward Earth.
Exhaustive calculations are run and re-run. Computer simulations are executed. All possibilities are taken into consideration, and yet there’s no alternative to be found; our world will face a close encounter with a comet in mere months’ time. Phone calls are made, a flurry of electronic messages fly between computer terminals across the world, consultations are held with top experts in the field. We are unprepared… what can we do? What does this mean for civilization as we know it? What will this speeding icy bullet from outer space do to our planet?
The answer? Nothing.
Nothing at all. In fact, it probably won’t even be very interesting to look at – if you can even find it when it passes by.
(Sorry for the let-down.)
There’s been a lot of buzz in the past several months regarding Comet Elenin, a.k.a. C/2010 X1, which was discovered by Russian astronomer Leonid Elenin on December 10, 2010. Elenin spotted the comet using a telescope in New Mexico remotely from his location in Lyubertsy, Russia. At that time it was about 647 million kilometers (401 million miles) from Earth… in the time since it has closed the distance considerably, and is now around 270 million km away. Elenin is a long-period comet, which means it has a rather large orbit around the Sun… it comes in from a vast distance, swings around the Sun and heads back out to the depths of the solar system – a round trip lasting over 10,000 years. During its current trip it will pass by Earth on October 16, coming as close as 35 million km (22 million miles).
Yes, 22 million miles.
That’s pretty far.
Way too far for us to be affected by anything a comet has to offer. Especially a not-particularly-large comet like Elenin.
Some of the doomy-gloomy internet sites have been mentioning the size of Elenin as being 80,000 km across. This is a scary, exaggerated number that may be referring to the size of Elenin’s coma – a hazy cloud of icy particles that surrounds a much, much smaller nucleus. The coma can be extensive but is insubstantial; it’s akin to icy cigarette smoke. Less than that, in fact… a comet’s coma and tail are even more of a vacuum than can be reproduced in a lab on Earth! In reality most comets have a nucleus smaller than 10km…that’s less than a billionth the mass of Earth (and a far cry from 80,000 km.) We have no reason to think that Elenin is any larger than this – it’s most likely smaller.
Ok, but how about the gravitational and/or magnetic effect of a comet passing by Earth? That’s surely got to do something, right? To Earth’s crust, or the tides? For the answer to that, I will refer to Don Yeomans, a researcher at NASA’s Near-Earth Object Program Office at JPL:
“Comet Elenin will not only be far away, it is also on the small side for comets. And comets are not the most densely-packed objects out there. They usually have the density of something akin to loosely packed icy dirt,” said Yeomans. “So you’ve got a modest-sized icy dirtball that is getting no closer than 35 million kilometers. It will have an immeasurably miniscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean’s tides than comet Elenin ever will.”
“It will have an immeasurably miniscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean’s tides than comet Elenin ever will.”
– Don Yeomans, NASA / JPL
And as far as the effect from Elenin’s magnetic field goes… well, there is no effect. Elenin, like all comets, doesn’t have a magnetic field. Not much else to say there.
But the claims surrounding Elenin have gone much further toward the absurd. That it’s going to encounter another object and change course to one that will cause it to impact Earth, or that it’s not a comet at all but actually a planet – Nibiru, perhaps? – and is on a collision course with our own. Or (and I particularly like this one) that alien spaceships are trailing Elenin in such a way as to remain undetected until it’s too late and then they’ll take over Earth, stealing our water and natural resources and turning us all into slaves and/or space munchies… or however the stories go. (Of course the government and NASA and Al Gore and Al Gore’s hamster are all in cahoots and are withholding this information from the rest of us. That’s a given.) These stories are all just that – stories – and have not a shred of science to them, other than a heaping dose of science fiction.
“We live in nervous times, and conspiracy theories and predictions of disaster are more popular than ever. I like to use the word cosmophobia for this growing fear of astronomical objects and phenomena, which periodically runs amuck on the Internet. Ironically, in pre-scientific times, comets were often thought to be harbingers of disaster, mostly because they seemed to arrive unpredictably – unlike the movements of the planets and stars, which could be tracked on a daily and yearly basis.”
– David Morrison, planetary astronomer and senior scientist at NASA’s Ames Research Center
The bottom line is this: Comet C/2010 X1 Elenin is coming, and it will pass by Earth at an extremely safe distance – 100 times the distance from Earth to the Moon. It will not be changing direction between now and then, it will not exert any gravitational effect on Earth, its magnetic field is nonexistent and there are no Star Destroyers cruising in its wake. The biggest effect it will have on Earth is what we are able to learn about it as it passes – after all, it is a visitor from the far reaches of our solar system and we won’t be seeing it again for a very, very long time.
I’m sure we’ll have found something else to be worried about long before then.
“This intrepid little traveler will offer astronomers a chance to study a relatively young comet that came here from well beyond our solar system’s planetary region. After a short while, it will be headed back out again, and we will not see or hear from Elenin for thousands of years. That’s pretty cool.”
– Don Yeomans
For more information about Elenin, check out this JPL news release featuring Don Yeomans, and there’s a special public issue of Astronomy Beat, a newsletter from the Astronomical Society of the Pacific, that features David Morrison of NASA’s Ames Research Center discussing many of the misconceptions about Elenin.
An updated chart of Elenin’s orbit and statistics can be viewed here.
Top image © Jason Major
SpacePod: Tour of Atlantis and the Launchpad
Jason Rhian had the chance to see Atlantis up close and personal — both in the Vehicle Assembly Building and on the launchpad. Since this is the last shuttle to go through processing and rolling to the pad, his closeup shots are especially poignant. It’s been busy at KSC: within a thirteen-hour period Kennedy Space Center saw the final rollout of the shuttle program as Atlantis headed to Launch Complex 39A, the final landing of space shuttle Endeavour as well as Endeavour’s tow back to her OPF. And inclement weather played a role, too. Jason said, “This was an amazing couple of days, a real whirlwind of activity. I, like many, am both thrilled and saddened to be covering such an important historical milestone.”
Young Supernova Has Bright Future
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Way back in 1987 we received a present from our neighboring galaxy, the Large Magellanic Cloud. It was an unprecedented event and the most exciting thing astronomers had seen in nearly four hundred years. It was a chance to study stellar evolution first-hand – with details allowed by modern equipment. Just what was it? The closest supernova explosion to date…
On June 8, 2011 a team of astronomers announced the supernova debris of SN 1987A, which has dimmed with time, is brightening again. The observations conclude a different power source is igniting the debris – beginning the transition from a supernova to a supernova remnant. “Supernova 1987A has become the youngest supernova remnant visible to us,” said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics (CfA) and leader of the long-term SN 1987A study with NASA’s Hubble Space Telescope.
Supernova remnants are made up of material ejected from the parent exploding star and interstellar matter picked up along the way. Long before the cataclysmic event, a ring of material is ejected – spreading out about one light-year (6 trillion miles) across. Inside the circle, the inner workings of the host star are rushing out to form the expanding debris cloud. It is lit by radioactive decay and brightening points towards a new power source. “It’s only possible to see this brightening because SN 1987A is so close and Hubble has such sharp vision,” Kirshner said.
What can we expect in SN1987A’s future? Right now it’s able to give us valuable information about the last few thousand years of a star’s life. By studying the unusual clumps and bumps in the ring’s structure, astronomers may be able to decode its history… History that will be lost as debris expansion wipes out the structure. “Young supernova remnants have personality,” Kirshner agreed.
For now, this young supernova is allowing us to take a look at a future so bright, it’s gotta’ wear shades.
Original Story Source: Harvard-Smithsonian Center for Astrophysics.
New Class of Stellar Explosion Sings the Blues
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A team of astronomers led by the California Institute of Technology (Caltech) have discovered a new, ultra-bright class of supernova – and it really sings the blues. Possibly one of the most luminous observable objects in the Cosmos, these new types of stellar explosions may help us better understand the origins of starbirth, unravel the mysteries of distant galaxies and even look back into the beginnings of our Universe…
“We’re learning about a whole new class of supernovae that wasn’t known before,” says Robert Quimby, a Caltech postdoctoral scholar and the lead author on a paper to be published in the June 9 on-line issue of the journal Nature. Not only did the team locate four instances of this new class, but the study also helped them unravel the questions behind two previously known supernovae which apparently belong in the same category.
As a graduate student at the University of Texas, Austin, Quimby came to the astronomy forefront in 2007 when he reported the brightest supernova ever found: 100 billion times brighter than the sun and 10 times brighter than most other supernovae. At the time, it was a record. Categorized as 2005ap, it had a rather strange spectral signature – a lack of hydrogen. But Quimby wasn’t the only one in the “class” doing homework, because the Hubble Space Telescope also detected an enigmatic event listed as SCP 06F6. It, too, had an unusual spectrum, but nothing led researchers to surmise it to be similar to 2005ap.
Enter Shri Kulkarni, Caltech’s John D. and Catherine T. MacArthur Professor of Astronomy and Planetary Science and a coauthor on the paper. They enlisted Quimby as a a founding member of the Palomar Transient Factory (PTF) – a project which scans the skies for unrecorded incident flashes of light which could signal possible supernova. With the eye of the 1.2-meter Samuel Oschin Telescope at Palomar Observatory, the colleagues went on to discover an additional four new supernovae events. Measuring the spectra with the 10-meter Keck telescopes in Hawaii, the 5.1-meter telescope at Palomar, and the 4.2-meter William Herschel Telescope in the Canary Islands, the astronomers discovered that all four objects had an unusual spectral signature. Quimby then realized that if you slightly shifted the spectrum of 2005ap—the supernova he had found a couple of years earlier—it looked a lot like these four new objects. The team then plotted all the spectra together. “Boom—it was a perfect match,” he recalls.
From there it didn’t take long to learn to sing the blues. The astronomers quickly figured out that by shifting the spectrum of SCP 06F6 caused it to align with previous findings. The results showed all six supernovae to be a similar type – all with very blue spectra – with the brightest wavelengths shining in the ultraviolet. This was the missing link that connected the two previously unexplained supernovae. “That’s what was most striking about this—that this was all one unified class,” says Mansi Kasliwal, a Caltech graduate student and coauthor on the Nature paper.
Even though astronomers now know these supernovae are related, the rest remains a mystery. “We have a whole new class of objects that can’t be explained by any of the models we’ve seen before,” Quimby says. “What we do know about them is that they are bright and hot—10,000 to 20,000 Kelvin; that they are expanding rapidly at 10,000 kilometers per second; that they lack hydrogen; and that they take about 50 days to fade away—much longer than most supernovae, whose luminosity is often powered by radioactive decay. So there must be some other mechanism that’s making them so bright.”
What could they be? One simulation leads to a pulsational pair-instability and the next points towards a magnetar. No matter what the answer is, the result is the illumination aids astronomers in studying distant dwarf galaxies, allowing them to measure the spectrum of the interstellar gas and uncover their composition. The findings could also “shed light” on what ancient stars may have been like… stretching back into the very beginnings of our Universe. “It is really amazing how rich the night sky continues to be,” Kulkarni says. “In addition to supernovae, the Palomar Transient Factory is making great advances in stellar astronomy as well.”
Original Story Source: California Institute of Technology.