Tag: imaging (page 2 of 3)

Hubble Juiced! ~ CU-Boulder to Design Space Telescope 1000 Times Sharper than Hubble



CU-Boulder to Design Space Telescope 1000 Times Sharper than Hubble
The Hubble Space Telescope


Excerpt from utahpeoplespost.com


Researchers from the Department of Astrophysical and Planetary Sciences at the University of Colorado Boulder are currently working on an improved version of space telescope that could provide space images nearly 1,000 times sharper than those provided by long-running Hubble.

The new space telescope, dubbed the Aragoscope, is named after a French astronomer called Francois Arago. The new telescope is exclusively designed by the CU- Boulder scientists and involves a brand new technology developed by the university. According to its designers, the space optical instrument would be lighter, slimmer, and sharper than Hubble.

Additionally, the Aragoscope will involve several independent pieces that can be later assembled in space. So, the launching costs of these smaller building blocks will be significantly reduced.
Traditionally, space telescopes have essentially been monolithic pieces of glass like the Hubble Space Telescope. But the heavier the space telescope, the more expensive the cost of the launch,”
said Anthony Harness, one of the researchers involved in the project and doctoral student at the CU-Boulder.

However, the new instrument will not replace Hubble, which is scheduled to be shut down in 5 years time. Last year, Hubble had its fifth and final maintenance service, and it was still in a pretty good shape although one of its six gyroscopes couldn’t be stabilized. Despite Hubble has been operating since 1990, NASA engineers hope that it will make it to its 30th anniversary.

If Hubble remains operational, NASA plans to use it along with its successor, the James Webb Space Telescope, which is scheduled to be launched in October 2018. Astronomers hope that the two space telescopes, which use two different imaging methods, would help them better understand the origins and early evolution of the universe.

But the UC-Boulder team claim that their new space telescope would surpass Hubble with its enhanced capacity of spotting distant Earth-like planets in the depths of a remote universe...

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The Weirdest, Coolest Stuff We’ve Learned About Rosetta’s Comet So Far


Various features on a smooth part of the comet's surface in the region named Imhotep.


Excerpt from wired.com

The Rosetta spacecraft has been studying comet 67P/Churyumov-Gerasimenko up close since August, collecting data of unprecedented detail and taking pictures of a starkly beautiful comet-scape. While the Philae lander has enjoyed much of the spotlight—partly thanks to its now-famous triple landing—Rosetta has been making plenty of its own discoveries.  

One of the biggest came last month, when scientists found that the chemical signature of the comet’s water is nothing like that on Earth, contradicting the theory that crashing comets supplied our planet with water. Comet 67P belongs to the Jupiter family of comets, and the findings also imply that these kinds of comets were formed at a wider range of distances from the sun than previously thought, says Michael A’Hearn, a planetary scientist at the University of Maryland, College Park, and member of the Rosetta science team.  

Today, scientists have published the first big set of results from Rosetta in a slew of papers in the journal Science. The results include measurements and analyses of the comet’s shape, structure, surface, and the surrounding dust and gas particles. Here are just a few of the amazing things they’ve discovered about Rosetta’s comet so far: 

The surface is fantastically weird  

The comet has quite the textured landscape, covered with steep cliffs, boulders, weird bumps, cracks, pits, and smooth terrain. There are fractures of all sizes, including one that’s several yards wide and stretches for more than half a mile along the comet’s neck. Researchers don’t yet know what caused these cracks.  The pits have steep sides and flat bottoms, ranging in size from a few tens to hundreds of feet wide. Jets of dust shoot out from some of the pits, suggesting that the ejection of material formed these features.  Another strange feature is what scientists are calling goosebumps—weird bumpy patches found particularly on steep slopes.

While other features such as pits and fractures range in sizes, all of the goosebumps are about 10 feet wide. No one knows what kind of process would make the bumps, but whatever it is could have played an important part in the comet’s formation. It may be breezy  Rosetta spotted dune- and ripple-like patterns,wind tails behind rocks, and even moats surrounding rocks, suggesting that a light breeze may blow dust along the surface. Such a gentle wind would have to come from gases leaking from below.

Because of the extremely low gravity on the comet, it wouldn’t take a strong gust to blow things around. It may have formed from two separate pieces  Or not. The most distinct feature of comet 67P is its odd, two-lobed shape, which resembles a duck. Although scientists have seen this lobed structure in other comets before, namely Borrelly and Hartley 2, none are as pronounced as comet 67P’s. Borrelly and Hartley 2 look more like elongated potatoes while 67P has a clearly defined head and body. The strange shape suggests the comet was once two separate pieces called cometesimals—what are now the duck’s head and body—that stuck together. 

The other possibility is that erosion ate away the parts around the neck. Preliminary evidence points to the first hypothesis.

“Probably most of us on the OSIRIS team lean toward thinking it was two cometesimals,” A’Hearn said. (OSIRIS is one of Rosetta’s imaging instruments.) But the scientists won’t have conclusive evidence until they study the comet in more detail. For example, they now see layering along the neck—if erosion carved out the comet’s duck shape, they should find the same same layering pattern continuing onto the other side of the neck. 

Black, with a tinge of red  

Even Rosetta’s color pictures show a grayish comet, but if you were to see it in person, you would see a pitch-black chunk of dust and ice, as it reflects only six percent of incoming light. By comparison, the moon reflects 12 percent of incoming light and Earth reflects 31 percent. But comet 67P’s not completely black, as it has a hint of red. Water, water, nowhere?  The comet’s covered in opaque, organic compounds. Although comet 67P is undoubtedly icy, it hardly shows any water ice on its surface at all. 

Which isn’t too surprising, as comets Tempel 1 and Hartley 2 didn’t have much ice on their surfaces either, A’Hearn says. Rosetta has yet to see sunlight reach every side of the comet yet, so there may still be some icy patches hidden from view.  But, researchers do see the comet spraying water vapor into space, which means water ice likely lies just beneath the surface. The ice doesn’t have to be more than a centimeter deep to be invisible from the infrared instruments that detect the ice. Indeed, the data from Philae’s first bounce suggested that there’s a hard layer of ice beneath 4 to 8 inches of dust. 

This duck floats  

If you could find a big enough pond, that is. Like other known comets, the density of comet 67P is about half that of water ice. Initial measurements reveal that it’s also very porous—as much as 80 percent of it may be empty space. Rosetta has found depressions, which may have formed when the surface collapsed over particularly porous material underneath. 

Different from every angle

As the comet nears the sun, it heats up, and ices and other volatile chemicals sublimate, spraying gases into space. So far, the most prominent gases that have been ejected are water vapor, carbon dioxide, and carbon monoxide. They spew out in different amounts from different parts of the comet. In particular, a lot of the water has been observed gushing out from the neck.

The comet will continue to get more active as it reaches its closest approach to the sun in mid-August. It will burst with stronger jets of gas and dust, and maybe even blast off chunks of itself. If the comet is this interesting now, A’Hearn says, just wait until it gets to its nearest point to the sun, when it’s just 1.29 times farther from the sun than Earth is.

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Spacecraft found on Mars – and it’s ours




Computer image of the Beagle 2


Excerpt from skyandtelescope.com
By Kelly Beatty  


On December 25, 2003, a British-built lander dropped to the Martian surface and disappeared without a trace. Now we know what happened to it.  It's hard to overstate how valuable the main camera aboard the Mars Reconnaissance Orbiter has been. The craft's High-Resolution Imaging Science Experiment, or HiRISE, uses a 20-inch (0.5-m) f/24 telescope to record details on the Martian surface as small as 0.3 m (about 10 inches). 

Beagle 2 seen from orbit by HiRISE
An overhead view of Beagle 2's landing site on Isidis Planitia shows a bright reflection from the long-lost spacecraft. Apparently it landed safely on December 25, 2003, and had begun to operate when it failed. NASA's Mars Reconnaissance Orbiter recorded this image on December 15, 2014. NASA / JPL / Univ. of Arizona / Univ. of Leicester - See more at: http://www.skyandtelescope.com/astronomy-news/beagle-2-lander-found-on-mars-01192015/#sthash.5KSZ8V6W.dpuf


Primarily it's a powerful tool for studying Martian geology at the smallest scales, and NASA scientists sometimes use it to track the progress (and even the arrivals) of their rovers. Beagle 2 on Mars  The clamshell-like Beagle 2 lander weighed just 30 kg, but it was well equipped to study Martian rocks and dust — and even to search for life. Beagle 2 consortium  But the HiRISE team has also been on a years-long quest to find the remains of Beagle 2, a small lander that had hitchhiked to the Red Planet with the European Space Agency's Mars Express orbiter. It descended to the Martian surface on Christmas Day in 2003 and was never heard from again. Space aficionados have debated its fate ever since. Did parachute failure lead to a crash landing? Did strong surface winds flip the saucer-shaped craft upside down? Did the Martians take it hostage?  Now, thanks to HiRISE, we know more of the story.  
An overhead view of Beagle 2's landing site on Isidis Planitia shows a bright reflection from the long-lost spacecraft. Apparently it landed safely on December 25, 2003, and had begun to operate when it failed. NASA's Mars Reconnaissance Orbiter recorded this image on December 15, 2014. NASA / JPL / Univ. of Arizona / Univ. of Leicester 


Images taken in February 2013 and June 2014 of the landing area in Isidis Planitia showed promising blips near the edge of each frame. A follow-up color view, acquired on December 15th and released three days ago, show a bright spot consistent with Beagle 2. The fully-opened lander would have been less than 2 m (6½ feet) across, so the craft is only barely resolved. Apparently the spacecraft made it to the surface intact, opened its clamshell cover, and had partially deployed its four petal-shaped solar-cell panels before something went awry. Beagle 2 seen from orbit by HiRISE  

One encouraging clue is that the bright reflection changes position slightly from image to image, consistent with sunlight reflecting off different lander panels. Two other unusual spots a few hundred meters away appears to be the lander's parachute and part of the cover that served as a shield during the 5½-km-per-second atmospheric descent...


On December 25, 2003, a British-built lander dropped to the Martian surface and disappeared without a trace. Now we know what happened to it.
It's hard to overstate how valuable the main camera aboard the Mars Reconnaissance Orbiter has been. The craft's High-Resolution Imaging Science Experiment, or HiRISE, uses a 20-inch (0.5-m) f/24 telescope to record details on the Martian surface as small as 0.3 m (about 10 inches). Primarily it's a powerful tool for studying Martian geology at the smallest scales, and NASA scientists sometimes use it to track the progress (and even the arrivals) of their rovers.
Beagle 2 on Mars
The clamshell-like Beagle 2 lander weighed just 30 kg, but it was well equipped to study Martian rocks and dust — and even to search for life.
Beagle 2 consortium
But the HiRISE team has also been on a years-long quest to find the remains of Beagle 2, a small lander that had hitchhiked to the Red Planet with the European Space Agency's Mars Express orbiter. It descended to the Martian surface on Christmas Day in 2003 and was never heard from again. Space aficionados have debated its fate ever since. Did parachute failure lead to a crash landing? Did strong surface winds flip the saucer-shaped craft upside down? Did the Martians take it hostage?
Now, thanks to HiRISE, we know more of the story. Images taken in February 2013 and June 2014 of the landing area in Isidis Planitia showed promising blips near the edge of each frame. A follow-up color view, acquired on December 15th and released three days ago, show a bright spot consistent with Beagle 2. The fully-opened lander would have been less than 2 m (6½ feet) across, so the craft is only barely resolved. Apparently the spacecraft made it to the surface intact, opened its clamshell cover, and had partially deployed its four petal-shaped solar-cell panels before something went awry.
Beagle 2 seen from orbit by HiRISE
An overhead view of Beagle 2's landing site on Isidis Planitia shows a bright reflection from the long-lost spacecraft. Apparently it landed safely on December 25, 2003, and had begun to operate when it failed. NASA's Mars Reconnaissance Orbiter recorded this image on December 15, 2014.
NASA / JPL / Univ. of Arizona / Univ. of Leicester
One encouraging clue is that the bright reflection changes position slightly from image to image, consistent with sunlight reflecting off different lander panels. Two other unusual spots a few hundred meters away appears to be the lander's parachute and part of the cover that served as a shield during the 5½-km-per-second atmospheric descent.
The initial images didn't just show up. They'd been requested and searched by Michael Croon of Trier, Germany, who'd served on the Mars Express operations team. Croon had asked for specific camera targeting through a program called HiWish, through which anyone can submit suggestions for HiRISE images. Read more about this fascinating sleuthing story.
"Not knowing what happened to Beagle 2 remained a nagging worry," comments Rudolf Schmidt in an ESA press release about the find. "Understanding now that Beagle 2 made it all the way down to the surface is excellent news." Schmidt served as the Mars Express project manager at the time.
Built by a consortium of organizations, Beagle 2 was the United Kingdom's first interplanetary spacecraft. The 32-kg (73-pound) lander carried six instruments to study geochemical characteristics of the Martian surface and to test for the presence of life using assays of carbon isotopes. It was named for HMS Beagle, the ship that carried a crew of 73 (including Charles Darwin) on an epic voyage of discovery in 1831–36.
- See more at: http://www.skyandtelescope.com/astronomy-news/beagle-2-lander-found-on-mars-01192015/#sthash.5KSZ8V6W.dpuf

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Liftoff! SpaceX Gets $1 Billion From Google and Fidelity

 Excerpt from  nbcnews.com SpaceX, the California-based rocket company that now has its sights set on a globe-spanning satellite constellation, says it has received a $1 billion investment from Google and Fidelity that values the c...

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Using X-rays, scientists read 2,000 year old scrolls charred by Mount Vesuvius


Mount Vesuvius today



By Amina Khan 
Excerpt from latimes.com

Talk about reading between the lines! Scientists wielding X-rays say they can, for the first time, read words inside the charred, rolled-up scrolls that survived the catastrophic eruption of Mt. Vesuvius nearly two millenniums ago.
Testing the scroll
Researchers Daniel Delattre, left, and Emmanuel Brun observe the scroll before X-ray phase contrast imaging begins. (J. Delattre)
The findings, described in the journal Nature Communications, give hope to researchers who have until now been unable to read these delicate scrolls without serious risk of destroying them.
The scrolls come from a library in Herculaneum, one of several Roman towns that, along with Pompeii, was destroyed when Mt. Vesuvius erupted in AD 79. This library, a small room in a large villa, held hundreds of handwritten papyrus scrolls that had been carbonized from a furnace-like blast of 608-degree-Fahrenheit gas produced by the volcano.

“This rich book collection, consisting principally of Epicurean philosophical texts, is a unique cultural treasure, as it is the only ancient library to survive together with its books,” the study authors wrote. “The texts preserved in these papyri, now mainly stored in the Officina dei Papiri in the National Library of Naples, had been unknown to scholars before the discovery of the Herculaneum library, since they had not been copied and recopied in late Antiquity, the middle ages and Renaissance.”
So researchers have tried every which way to read these rare and valuable scrolls, which could open a singular window into a lost literary past. The problem is, these scrolls are so delicate that it’s nearly impossible to unroll them without harming them. That hasn’t kept other researchers from trying, however – sometimes successfully, and sometimes not.

“Different opening techniques, all less effective, have been tried over the years until the so-called ‘Oslo method’ was applied in the 1980s on two Herculaneum scrolls now in Paris with problematic results, since the method required the rolls to be picked apart into small pieces,” the study authors wrote. (Yikes.)

Any further attempts to physically open these scrolls were called off since then, they said, “because an excessive percentage of these ancient texts was irretrievably lost by the application of such methods.”
This is where a technique like X-ray computed tomography, which could penetrate the rolled scrolls, would come in handy. The problem is, the ancient writers used ink made of carbon pulled from smoke residue. And because the papyrus had been carbonized from the blazing heat, both paper and ink are made of roughly the same stuff. Because the soot-based ink and baked paper have about the same density, until now it’s been practically impossible to tell ink and paper apart.

But a team led by Vito Mocella of the Institute for Microelectronics and Microsystems in Naples, Italy, realized they could use a different technique called X-ray phase-contrast tomography. Unlike the standard X-ray CT scans, X-ray phase-contrast tomography examines phase shifts in the X-ray light as it passes through different structures.
Using the technique, the scientists were able to make out a few words and letters from two scrolls, one of them still rolled.

Reading these scrolls is difficult; computer reconstructions of the rolled scroll reveal that the blast of volcanic material so damaged its once-perfect whorls that its cross section looks like a half-melted tree-ring pattern. The paper inside has been thoroughly warped, and some of the letters on the paper probably distorted almost beyond recognition.
Nonetheless, the researchers were able to read a number of words and letters, which were about 2 to 3 millimeters in size. On an unrolled fragment of a scroll called “PHerc.Paris. 1,” they were able to make up the words for “would fall” and “would say.” In the twisted, distorted layers of the rolled-up papyrus called “PHerc.Paris. 4,” they could pick out individual letters: alpha, nu, eta, epsilon and others.

The letters in “PHerc.Paris. 4” are also written in a distinctive style with certain decorative flourishes that seemed very similar to a scroll called “PHerc. 1471,” which holds a text written by the Epicurean philosopher Philodemus. The researchers think they were written in the second quarter of the first century BC.


Ultimately, the researchers wrote, this work was a proofof concept to give other researchers a safe and reliable way to explore ancient philosophical works that were until now off-limits to them.

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The Whispering Mind: The Enduring Conundrum of Consciousness

It's an old question: what is consciousness? Today, sophisticated brain imaging technologies, clinical studies, as well as the newfound ability to listen to the whisper of even an individual nerve cell, are bringing scientists closer than ever to t...

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Philae comet lander eludes discovery

Artist's conceptionExcerpt from bbc.comEfforts to find Europe's lost comet lander, Philae, have come up blank. The most recent imaging search by the overflying Rosetta "mothership" can find no trace of the probe. Philae touched down on 67...

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Ghost Bomber Captured on Google Earth?

An Avro Lancaster World War 2 era bomber is captured through Google Earth satellite imaging over Stukeley Meadows, Huntingdon, England. What is so mysterious about this image is that no air shows, where such an outdated flying machine may be resurrecte...

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Titanic Mystery Solved ~ 2014 Documentary

The RMS TitanicAs the 100th anniversary of the sinking of the Titanic approaches, a team of scientists, engineers, archaeologists and imaging experts have joined forces to answer one of the most haunting questions surrounding the legendary disaster:...

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NASA captures high-resolution images of comet Sliding Spring


 Diagrams show how comet will approach Mars.


The Mars Reconnaissance Orbiter captures images of Comet C/2013 A1, also known as Sliding Spring after the observatory which discovered it, as it flies past Mars on October 19th. The comet originated in the Oort Cloud, which is located in the distant reaches of our solar system.

These images were taken by the Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera while the comet flew approximately 86,000 miles from Mars at a speed of 35,700 miles per hour (57,400 km/h) relative to the planet.
Greg Giles



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How can there be ice on Scorching Mercury? NASA Report

NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washingtonnasa.govMESSENGER Finds New Evidence for Water Ice at Mercury's Poles Mercury's North Polar Region Acquired By The Arecibo Observatory A Mosaic of MESSEN...

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Cosmic dust may have distorted cosmic inflation breakthrough


The 10-meter South Pole Telescope and the BICEP (Background Imaging of Cosmic Extragalactic Polarization) Telescope at Amundsen-Scott South Pole Station, which detected evidence of gravitational waves, is seen against the night sky with the Milky Way in this National Science Foundation picture taken in August 2008.

By Ben P. Stein, Inside Science

Harvard researchers rocked the science community last March with an apparent discovery of gravitational ripples that gave credence to cosmic inflation theory – a finding that met as much skepticism as enthusiasm. Now, further analysis raises more doubts.


"Extraordinary claims require extraordinary evidence." This phrase, popularized by the late Carl Sagan, kept going through my head on March 17, the day that researchers involved with BICEP2, a telescope in Antarctica, made a big announcement at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

The researchers reported that BICEP2 detected gravitational waves from the first moments after the big bang, a feat, which if confirmed, would open up a new field of study and would surely be recognized in a future Nobel Prize.

Gravitational waves are ripples in space and time. They're created when any object with mass accelerates. However, they're extremely weak, making them very hard to detect directly. Even for the most massive and cataclysmic events, such as the collision of two black holes, their effects, observed from Earth, are very hard to detect.

If you're looking for a detectable gravitational wave signal, what bigger event can there be than cosmic inflation? According to inflation theory, the universe multiplied its size by as much as 10 trillion trillion trillion times in the first fractions of a second after the big bang.  Inflation would have generated lots of gravitational waves. In turn, gravitational waves can subtly change the properties of light that they pass through. Specifically, they can slightly affect the polarization of light, the direction in which light's electric fields vibrate. The universe's rapid expansion during inflation would have amplified the waves' imprint on the early light in the universe.

The state-of-the-art BICEP2 experiment, which uses super-sensitive superconducting sensors, could detect tiny changes in polarization in the cosmic microwave background, the very first light released in the universe, which is still reaching us today. The BICEP2 researchers reported a very high polarization signal, known as B-mode polarization after its characteristics, in the cosmic microwave background, which they interpreted as a strong gravitational wave signal in the early universe.

Detecting this polarization signal was a striking result, announced in a series of scientific talks and a press conference shortly after a preprint of the paper was posted online. Notice these last two points: announced at a press conference, and a preprint posted online. A preprint is a written paper that has not been formally reviewed by independent peers or published in a scientific journal.

Nonetheless, scientists and reporters alike reported excitement over the results. If true, they would provide the greatest experimental support yet of cosmic inflation, and the first direct detection of gravitational waves. Previously, gravitational waves have been detected indirectly, such as in observations of pairs of stars falling towards each other: they were losing energy in the form of gravitational waves.

On the day of the BICEP2 announcement, and for many days afterward, people were largely accepting the results as correct and already jumping to the implications of the BICEP2 results for what appeared to be a new era of gravitational-wave cosmology.
In writing my story for Inside Science News Service, I was fortunate to get an early voice of skepticism from David Spergel, a theoretical cosmologist at Princeton University in New Jersey. He commented:

"Given the importance of this result, my starting point is to be skeptical. Most importantly, there are several independent experimental groups that will test this result in the next year."
Spergel explained that the new gravitational wave measurements did not appear to agree with those of previous experiments, known as WMAP and Planck, unless the simplest models of inflation were replaced by more complicated ones. On the first day and week of coverage, I became very disappointed with the many commentators who disregarded or underemphasized that the earlier measurements from instruments on WMAP and Planck, which had been reported and covered for years.

Sure enough, in the weeks that followed, other researchers pointed out that the signal that BICEP2 detected may have been attributable to the polarization of light caused by dust in our galaxy. The BICEP2 team certainly knew that dust could also polarize light in a similar way to gravitational waves, but they used a model, based on the data that was available from the Planck satellite, that, the other researchers pointed out, may have underestimated the amount of dust in the part of the sky they were studying.

The BICEP2 paper underwent peer review and was published in Physical Review Letters. As a result of the peer-review process, the researchers made revisions, including removing the model that contained the lower estimates of dust based on the earlier Planck data, and thereby reducing the certainty with which they could state that they accounted for signals from interstellar dust.

During the summer, the BICEP2 and Planck collaborations agreed to work together to analyze their data, to help determine if gravitational waves had really been detected.

This week, the Planck team issued a preprint, based on an analysis of much additional data, showing a comprehensive map of dust in the sky. According to their analysis, the signal in the part of sky that BICEP2 analyzed could be completely attributable to dust and not to gravitational waves.

But, the story is not over. For starters, keep in mind the new preprint, like all newly posted publications, still needs to undergo formal peer review.

And the latest data do not completely rule out the possibility that the BICEP2 group detected a gravitational wave signal. If the evidence holds up at all, it would likely be a weaker signal, after accounting for the dust. Or, the gravitational-wave signal may completely turn to dust.

It may be possible to detect primordial gravitational waves in a different, less dusty part of the sky, or with new measurements by BICEP2, Planck or the many other experiments that are looking for them.  Just as the first reported detections of exoplanets turned out to be false, perhaps this is a prelude to an actual detection of gravitational waves.

"You cannot ignore dust," he quotes from Planck scientist Charles Lawrence of NASA’s Jet Propulsion Laboratory in Pasadena, California.

The biggest lesson, to me, is that no one should rush to make announcements and pronouncements, whether big or small, even in the face of intense competition and the alluring prospects of launching a new field of study and winning a Nobel Prize. 

Scientists, and the rest of the public, should follow the time-tested scientific practice of subjecting claims to sufficient levels of scrutiny, and waiting for other groups to validate results, before making bold statements. At the very least, there have been major caveats and qualifiers in announcing new data with potentially huge implications.

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Criticism of Study Detecting Ripples From Big Bang Continues to Expand

The lab housing the Bicep2 telescope near the South Pole. Credit Steffen Richter, Harvard University
nytimes.com

Stardust got in their eyes.
In the spring a group of astronomers who go by the name of Bicep announced that they had detected ripples in the sky, gravitational waves that were the opening notes of the Big Bang. The finding was heralded as potentially the greatest discovery of the admittedly young century, but some outside astronomers said the group had underestimated the extent to which interstellar dust could have contaminated the results — a possibility that the group conceded in its official report in June.

Now a long-awaited report by astronomers using data from the European Space Agency’s Planck satellite has confirmed that criticism, concluding that there was enough dust in Bicep’s view of the sky to produce the swirly patterns without recourse to primordial gravitational waves.
“We show that even in the faintest dust-emitting regions there are no ‘clean’ windows in the sky,” the Planck collaboration, led by Jean-Loup Puget of the Astrophysical Institute in Paris, wrote in a paper submitted to the journal Astronomy & Astrophysics and posted online Monday.
As a result, cosmologists like the Bicep crew cannot ignore dust in their calculations. “However,” said Jonathan Aumont, another of the Planck authors, also from the Paris institute, “our work does not imply that they did not measure at all a cosmological signal.

Moreover, due to the very different observation techniques and signal processing in the Bicep2 and Planck experiments, we cannot say how much of the signal they measured is due to dust” and how much to gravitational waves.

So this is not the end of the story, both the Planck scientists and the Bicep group agree. But the original euphoria that the secrets of inflation and quantum gravity might be at hand has evaporated. Planck and Bicep are now collaborating on a detailed comparison of their results.

John M. Kovac of the Harvard-Smithsonian Center for Astrophysics, lead author of the Bicep paper, said the new report confirmed in greater detail the trend suggested by the first Planck papers in the spring, which indicated there is more dust even in the cleanest parts of the galaxy than anyone had thought.

Raphael Flauger of the Institute for Advanced Study in Princeton, N. J., who first raised the issue of dust in the Bicep report, said it confirmed what he had thought. “It doesn’t leave a lot of wiggle room,” he wrote in an email, “and it seems clear that at least the majority of the signal is caused by dust.”

The gravitational waves may exist, although they would be weaker than the Bicep analysis indicated, causing theorists to reshuffle their ideas. As Richard Bond, an early universe expert at the University of Toronto and a Planck team member, put it: “Planck showed that dust could possibly be the entire Bicep2 signal, but Planck alone cannot decide. We have to do this in combination with Bicep2.”

The joint comparison and Planck’s own polarization maps are due at the end of the year.

If true, Bicep’s detection of gravitational waves would confirm a theory that the universe began with a violent outward antigravitational swoosh known as inflation, the mainspring of Big Bang theorizing for the last three decades.

The disagreement over the Bicep finding will not mean the end of inflation theory; it just means it will be harder for cosmologists to find out how it worked. The Bicep group and an alphabet soup of competitors are soldiering on with new telescopes and experiments aimed at peeling away the secrets of the sky.

Michael S. Turner, a cosmologist at the University of Chicago, said: “This is going to be a long march, but the goal of probing the earliest moments of the universe makes it well worth the effort. Dust is the bane of the existence of astrophysicists — and cosmologists. It is everywhere, and yet our understanding of it is very poor.”

Others are less optimistic. Paul J. Steinhardt of Princeton University, a critic of the Bicep paper — and of inflation theory — said in an email that the Bicep paper should be retracted, “and we should return to good scientific practice.”

The Bicep observations are the deepest look yet into a thin haze of microwaves, known as cosmic background radiation, left over from end of the Big Bang, when the cosmos was about 380,000 years old.

According to theory, the onset of inflation, less than a trillionth of a second after time began, should have left ripples in space-time known as gravitational waves. They would manifest as corkscrew patterns in the direction of polarization of the cosmic microwaves.
The Bicep group — its name is an acronym for Background Imaging of Cosmic Extragalactic Polarization — is led by Dr. Kovac; Jamie Bock of Caltech; Clement Pryke of the University of Minnesota; and Chao-Lin Kuo of Stanford. They have deployed a series of radio telescopes at the South Pole in search of the swirl pattern. Their most recent, Bicep2, detected a signal in the sweet spot for some of the most popular models of inflation, leading to a splashy news conference and a summer of controversy and gossip.
As the critics pointed out, things besides quantum ripples from the beginning of time could produce those swirls, including light from interstellar dust polarized by magnetic fields in space.
Planck, launched in 2008 to survey the cosmic microwave sky, can distinguish the characteristic signature of dust by comparing the sky brightness in several radio frequencies, as well as measuring its direction of polarization. Bicep2, in contrast, looked at only one frequency, 150 gigahertz.

The Bicep astronomers asked for Planck data on their patch of sky, but it was not available until now because of suspected instrument problems, Dr. Aumont said. So they extrapolated from existing data to conclude that there was little dust interfering with their observations.

The new Planck report has knocked the pins out from under that. But there are still large uncertainties that leave room for primordial gravitational waves at some level. For example, the Planck team had to extrapolate some of its own measurements.

As the Planck report says, “This result emphasizes the need for a dedicated joint Planck-Bicep2 analysis.”

The group hopes this analysis will include data from the latest Bicep telescope, called the Keck Array, which has been gathering data for several months. In an interview this summer, Dr. Kovac said, “It’s been a funny year to be in the spotlight like this.” He said the group stood behind its work, even if the ultimate interpretation of the measurements is up for grabs.

Acknowledging that dust would not be as sexy a discovery as ripples from inflation, Dr. Kovac said, “It’s really important as an experimentalist that you can divorce yourself from an investment in what the answer is.”

He went on: “One thing that would distress me bitterly is if a major mistake in the measurement or of the analysis would come to light. The most pressing question is, what are the dust contributions to the signal?”

Stay tuned.

Lyman Page, an astrophysicist at Princeton, said the episode illustrated the messy progress of science.

“Taking a step back,” he said by email, “it is amazing that a precise measurement of the cosmos can be made, discussed in fullness, and refuted by another measurement in such a short amount of time. It is testament to a healthy field.”

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