A new alien-planet–hunting telescope has just come online in Chile, and it could help scientists peer into the atmospheres of relatively small planets circling nearby stars.
The Next-Generation Transit Survey (NGTS for short) — located at the European Southern Observatory's (ESO) Paranal Observatory — is designed to seek out planets two to eight times the diameter of Earth as they pass in front of their stars. Such a planet will cause the light of the star to dip ever so slightly when passing in front of it, allowing the telescope to detect the planet during its transit.
"We are excited to begin our search for small planets around nearby stars," Peter Wheatley, an NGTS project lead from the University of Warwick, U.K., said in as statement. "The NGTS discoveries, and follow-up observations by telescopes on the ground and in space, will be important steps in our quest to study the atmospheres and composition of small planets such as the Earth."
The instrument is designed to measure the brightness of stars more accurately than any other ground-based wide-field survey, ESO officials said. The NGTS is made up of 12 telescopes that will operate robotically, according to ESO. Astronomers using the survey hope to find small, bright planets in order to learn more about the densities of them.
In the hunt for extraterrestrial life, scientists started by searching for a world orbiting a star just like the sun. After all, the steady warmth of that glowing yellow ball in the sky makes life on Earth possible.
But as astronomers continue to discover thousands of planets, they’re realizing that if (or when) we find signs of extraterrestrial life, chances are good that those aliens will orbit a star quite different from the sun—one that’s redder, cooler, and at a fraction of the sun’s size and mass. So in the quest for otherworldly life, many astronomers have set their sights on these small stars, known as red dwarfs or M dwarfs.
At first, planet-hunting astronomers didn’t care so much about M dwarfs. After the first planet outside the solar system was discovered in 1995, scientists began hunting for a true Earth twin: a rocky planet like Earth with an orbit like ours around a sun-like star. Indeed, the search for that kind of system drove astronomers through most of the 2000s, says astronomer Phil Muirhead of Boston University.
But then astronomers realized that it might be technically easier to find planets around M dwarfs. Detecting another planet is really hard, and scientists rely on two main methods. In the first, they look for a drop in a star’s brightness when a planet passes in front of it. In the second, astronomers measure the slight wobble of a star, caused by the gentle gravitational tug of an orbiting planet. With both of these techniques, the signal is stronger and easier to detect for a planet orbiting an M dwarf. A planet around an M dwarf also orbits more frequently, increasing the chances that astronomers will spot it.
M dwarfs got a big boost from the Kepler space telescope, which launched in 2008. By staring at small patch of the sky, the telescope searches for suddenly dimming stars when a planet passes in front of them. In doing so, the spacecraft discovered a glut of planets—more than 1,000 at the latest count—it found a lot of planets around M dwarfs. “Kepler changed everything,” Muirhead said. Because M-dwarf systems are easier to find, the bounty of such planets is at least partly due to a selection effect. But, as Muirhead points out, Kepler is also designed to find Earth-sized planets around sun-like stars, and the numbers so far suggest that M-dwarfs may offer the best odds for finding life.
“By sheer luck you would be more likely to find a potentially habitable planet around an M dwarf than a star like the sun,” said astronomer Courtney Dressing of Harvard. She led an analysis to estimate how many Earth-sized planets—which she defined as those with radii ranging from one to one-and-a-half times Earth’s radius—orbit M dwarfs in the habitable zone, the region around the star where liquid water can exist on the planet’s surface. According to her latest calculations, one in four M dwarfs hosts such a planet.
That’s higher than the estimated number of Earth-sized planets around a sun-like star, she says. For example, an analysis by astronomer Erik Petigura of UC Berkeley suggests that fewer than 10 percent of sun-like stars have a planet with a radius between one and two times that of Earth’s.
This illustration shows Kepler-186f, the first rocky planet found in a star’s habitable zone. Its star is an M dwarf. NASA Ames/SETI Institute/JPL-Caltech
M dwarfs have another thing going for them. They’re the most common star in the galaxy, comprising an estimated 75 percent of the Milky Way’s hundreds of billions of stars. If Dressing’s estimates are right, then our galaxy could be teeming with 100 billion Earth-sized planets in their stars’ habitable zones.
To be sure, these estimates have lots of limitations. They depend on what you mean by the habitable zone, which isn’t well defined. Generally, the habitable zone is where it’s not too hot or too cold for liquid water to exist. But there are countless considerations, such as how well a planet’s atmosphere can retain water. With a more generous definition that widens the habitable zone, Petigura’s numbers for Earth-sized planets around a sun-like star go up to 22 percent or more. Likewise, Dressing’s numbers could also go up. Astronomers were initially skeptical of M-dwarf systems because they thought a planet couldn’t be habitable near this kind of star. For one, M dwarfs are more active, especially during within the first billion years of its life. They may bombard a planet with life-killing ultraviolet radiation. They can spew powerful stellar flares that would strip a planet of its atmosphere.
And because a planet will tend to orbit close to an M dwarf, the star’s gravity can alter the planet’s rotation around its axis. When such a planet is tidally locked, as such a scenario is called, part of the planet may see eternal daylight while another part sees eternal night. The bright side would be fried while the dark side would freeze—hardly a hospitable situation for life.
But none of these are settled issues, and some studies suggest they may not be as big of a problem as previously thought, says astronomer Aomawa Shields of UCLA. For example, habitability may depend on specific types and frequency of flares, which aren’t well understood yet. Computer models have also shown that an atmosphere can help distribute heat, preventing the dark side of a planet from freezing over.
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Excerpt from theregister.co.uk New research suggests planets similar to Earth are much more common across the galaxy than previously thought.
And the boffins behind this revelation have also come up with a simple chemical recipe for creating habitable worlds suitable for use by advanced super-powered intelligences and/or deities etc.
"Our solar system is not as unique as we might have thought," says Courtney Dressing, graduate student at the Harvard-Smithsonian Center for Astrophysics.
Ms Dressing bases this assertion on data from the HARPS-North (High-Accuracy Radial velocity Planet Searcher, Northern) instrument on the 3.6-metre Telescopio Nazionale Galileo in the Canary Islands. This is designed to accurately measure the masses of small, Earthish-sized worlds. Once you have mass and volume, as any fule kno, you have density and thus a fair notion of what a given alien world is made of - and this tells you whether it can be much like Earth.
So chuffed are the Harvard boffins with this discovery that they've come up with a handy "recipe" for cooking up a world with Earth-esque life on it, thus:
1 cup magnesium 1 cup silicon 2 cups iron 2 cups oxygen ½ teaspoon aluminum ½ teaspoon nickel ½ teaspoon calcium ¼ teaspoon sulfur dash of water delivered by asteroids
Blend well in a large bowl, shape into a round ball with your hands and place it neatly in a habitable zone area around a young star. Do not over mix. Heat until mixture becomes a white hot glowing ball. Bake for a few million years. Cool until color changes from white to yellow to red and a golden-brown crust forms. It should not give off light anymore. Season with a dash of water and organic compounds. It will shrink a bit as steam escapes and clouds and oceans form. Stand back and wait a few more million years to see what happens.
If you are lucky, a thin frosting of life may appear on the surface of your new world.
Excerpt from bbc.comAstronomers have proved that they can accurately tell the age of a star from how fast it is spinning. We know that stars slow down over time, but until recently there was little data to support exact calculations. For ...
msn.com When Russian miners pulled a strange red and green stone out of the ground, they immediately knew it was different to the thousands of tons of ore they process every day.
In fact, what workers at Alrosa 's Udachnaya diamond mine had unearthed was a 30mm rock that contained 30,000 diamonds - a conentration 1m times higher than normal.
However, despite the rare find the company donated the rock to the Russian Academy of Sciences, as the diamonds are so small that they cannot be used as gems.
After scanning the rock with X-rays, scientists found that the diamonds inside measure just 1mm and are octahedral in shape - similar to two pyramids stuck together at the base. The red and green colouring comes from larger crystals of garnet, olivine and pyroxene.
"The exciting thing for me is there are 30,000 itty-bitty, perfect octahedrons, and not one big diamond," said Larry Taylor, a geologist at the University of Tennessee, who presented the findings at the American Geophysical Union 's annual meeting. "It's like they formed instantaneously. This rock is a strange one indeed."
Scientists are excited at the finding as they hope it will shed further light on how diamonds are made. They know diamonds are crystals of pure carbon that form under crushing pressures and intense heat, mostly formed in the Earth's mantle, the layer beneath the crust or surface layer, at a depth of about 150km. However, certain processes in their creation remain a mystery.
"The [chemical] reactions in which diamonds occur still remain an enigma," Mr Taylor told Live Science, which first reported the story.
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A better understanding of how the universe was formed comes from what is left of a meteorite. The meteorite is named Semarkona, and it touched down in India in the 1940′s. Arizona State University’s School of Earth and Space Exploration wanted to measure the magnetic levels of the meteorite, and in doing so, they have shown we are closer to understanding how the solar system was formed.
It would seem rather insignificant given its size of just one and a half pounds, but it was formed over four and a half billion years ago. Researchers admit the magnetic flux of the rock mimics the magnetic forces here on the planet.
Every magnetic fluctuation of Semarkona has been mapped and the fluctuations of the magnetic field recorded in a study that is the first of its kind. This has given researchers more insight into the magnetic fields that were pivotal in forming the universe.
The study, aptly named Solar nebula magnetic fields recorded in the Semarkona meteorite was published in the November 13 issue of the journal Science.
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...
NEW YORK—The Obama administration announced Thursday that it will create the largest marine reserve in the world by expanding an existing monument around U.S.-controlled islands and atolls in the central Pacific.
The Pacific Remote Islands Marine National Monument will now be nearly 490,000 square miles, nearly three times the size of California and six times larger than its previous size. Commercial fishing, dumping, and mining will be prohibited in the reserve, but recreational fishing will be allowed with permits, and boaters may visit the area.
The protected area that Secretary of State John Kerry announced this morning is actually smaller than the 782,000 square miles that the president initially considered. But environmentalists, preservationists, and conservation groups that had pushed for the expansion called President Barack Obama's designation a historic victory in their efforts to limit the impact of fishing, drilling, and other activities that threaten some of the world's most species-rich waters.
MAGGIE SMITH, NG STAFF. SOURCES: U.S. FISH AND WILDLIFE SERVICE; USGS; MARINE CONSERVATION INSTITUTE
"What has happened is extraordinary. It is history making. There is a lot of reason we should be celebrating right now," said Elliott Norse, founder and chief scientist of the Seattle-based Marine Conservation Institute.
Enric Sala, an ocean scientist and National Geographic Explorer-in-Residence, called the newly expanded monument "a great example of marine protection."
During the past several years, Sala and National Geographic's Pristine Seas project—which aims to explore, survey, and protect several of the last wild places in the world's oceans—have been key players in expeditions to the region that helped to put a spotlight on its biodiversity. Sala also met with White House officials to make the scientific case for expanding the Pacific Remote Islands monument.
Tentacles of a sea anemone provide cover for a transparent shrimp in Kingman Reef, which is part of the existing marine sanctuary. Photograph by Brian Skerry, National Geographic Creative
In announcing the expansion of protected marine areas, Kerry said, “We’re committed to protecting more of the world's ocean. Today, one to three percent of the ocean is protected, that's it. That's why President Obama will sign a proclamation today that will create one of the largest maritime protected areas in the world. It will be protected in perpetuity.”
Michael Boots, chairman of the White House's Council on Environmental Quality, made clear that by expanding protected areas, the administration sought to balance the need to preserve a range of marine species with concerns from the fishing industry, which had warned about the economic impact of curtailing deep-sea fishing areas.
"We thought [the monument decision] was a good way to balance what the science was telling us was important to protect and the needs of those who use the area," Boots said.
The administration said in a statement late Wednesday that "expanding the monument will more fully protect the deep coral reefs, seamounts, and marine ecosystems unique to this part of the world, which are also among the most vulnerable areas to the impacts of climate change and ocean acidification."
In June, when he first announced his intent to expand the monument, Obama said, "I'm using my authority as president to protect some of our nation's most pristine marine monuments, just like we do on land."
The June announcement was followed by a public comment period and further analysis by the White House, officials said. Thousands of people submitted comments, with many conservation groups and scientists offering their support. Some fishing and cannery groups, as well as a few members of the U.S. Congress opposed the expansion, citing the potential a loss of commercial fishing grounds.
Norse said that the newly protected areas will safeguard endangered seabirds and other key species, including five endangered sea turtle species (such as loggerheads and leatherbacks), sooty terns and other terns, silky sharks and oceanic whitetip sharks, beaked whales, manta rays, red-tailed tropic birds, and deep-sea corals.
The expanded monument will help ensure that "there are some places that are as pristine as possible for as long as possible," Norse said. "I think a hundred years from now, people will be praising Barack Obama for having the vision to protect the Pacific remote islands."
"A Big Step"
Obama's Democratic administration is building on a national monument that was first created by his predecessor, Republican President George W. Bush, suggesting that "ocean protection may be one of the last bipartisan issues" in the politically divided United States, says David Helvarg, the author of several books on the ocean and the founder of the advocacy group Blue Frontier Campaign.
Democratic and Republican presidents going all the way back to Teddy Roosevelt, a Republican who served from 1901 to 1909, have used the 1906 Antiquities Act to designate national monuments. The law requires simply that an area be unique and considered worthy of protection for future generations. This is the 12th time Obama has used his authority under the Antiquities Act to protect environmental areas.
The area being protected by the administration will expand the protected areas from 50 miles offshore to 200 miles offshore around three areas—Wake Island, Johnston Atoll, and Jarvis Island—the maximum reach of the United States’ exclusive economic zone. The current 50-mile offshore protections around the Howland and Baker islands, and Kingman Reef and Palmyra Atoll, will not change.
"Although 71 percent of our planet is covered with saltwater, we have protected much more of the land than the ocean," Helvarg said. But the newly expanded monument is a big step in the right direction, he added.
Enforcing fishing bans in the monument will be a big challenge, Kerry acknowledged. "Agreements won't matter if no one is enforcing them," he said. "It's going to take training and resources." Kerry said one measure that could help deter illegal fishing in the region, as well as around the world, would be to implement the Port State Measures Agreement, an international treaty that requires member nations to prevent illegally caught fish from entering the market. Eleven nations or parties have ratified the agreement, but a total of 25 must sign before the treaty will take effect.
"Our goal is to get this done this year," Kerry said.
Meanwhile, efforts to preserve more biologically diverse waters continue.
This week, National Geographic Society announced that it is dramatically expanding its campaign to help protect marine areas, with a goal of persuading governments to officially safeguard more than 770,000 square miles.
The plan, announced by former President Bill Clinton, includes programs that target the Seychelles—an archipelago in the Indian Ocean—northern Greenland, and South America's Patagonia region. The program builds on National Geographic's Pristine Seas project, which has financed ten scientific expeditions to remote areas of ocean around the world, including in the South Pacific and off Africa, Russia, and South America.
Excerpt from the journal Naturenature.comTransmission spectroscopy has so far detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) pla...
Human brains are about three times as large as those of our early australopithecines ancestors that lived 4 million to 2 million years ago, and for years, scientists have wondered how our brains got so big. A new study suggests social competition could be behind the increase in brain size. Credit NIH, NADA
There are many ways to try to explain why human brains today are so big compared to those of early humans, but the major cause may be social competition, new research suggests.
But with several competing ideas, the issue remains a matter of debate.
Compared to almost all other animals, human brains are larger as a percentage of body weight. And since the emergence of the first species in our Homo genus (Homo habilis) about 2 million years ago, the human brain has doubled in size. And when compared to earlier ancestors, such as australopithecines that lived 4 million to 2 million years ago, our brains are three times as large. For years, scientists have wondered what could account for this increase.
The three major hypotheses have focused on climate change, the demands of ecology, and social competition. A new statistical analysis of data on 175 fossil skulls supports the latter hypothesis.
Behind the hypotheses
The climate idea proposes that dealing with unpredictable weather and major climate shifts may have increased the ability of our ancestors to think ahead and prepare for these environmental changes, which in turn led to a larger, more cognitively adept brain. The ecology hypothesis states that, as our ancestors migrated away from the equator, they encountered environmental changes, such as less food and other resources. "So you have to be a little bit more clever to figure it out," said David Geary, a professor from the University of Missouri. Also, less parasite exposure could have played a role in the makings of a bigger brain. When your body combats parasites, it cranks up its immune system, which uses up calories that could have gone to boost brain development. Since there are fewer parasites farther away from the equator, migrating north or south could have meant that our predecessors had more opportunity to grow a larger brain because their bodies were not fighting off as many pathogens. Finally, other researchers think that social competition for scarce resources influenced brain size. As populations grow, more people are contesting for the same number of resources, the thinking goes. Those with a higher social status, who are "a little bit smarter than other folks" will have more access to food and other goods, and their offspring will have a higher chance of survival, Geary said.
Those who are not as socially adept will die off, pushing up the average social "fitness" of the group. "It's that type of process, that competition within a species, for status, for control of resources, that cycles over and over again through multiple generations, that is a process that could easily explain a very, very rapid increase in brain size," Geary said. Weighing the options To examine which hypothesis is more likely, Geary and graduate student Drew Bailey analyzed data from 175 skull fossils — from humans and our ancestors — that date back to sometime between 10,000 ago and 2 million years ago. The team looked at multiple factors, including how old the fossils were, where they were found, what the temperature was and how much the temperature varied at the time the Homo species lived, and the level of parasites in the area. They also looked at the population density of the region in order to measure social competition, "assuming that the more fossils you find in a particular area at a particular time, the more likely the population was larger," Geary said. They then used a statistical analysis to test all of the variables at once to see how well they predicted brain size. "By far the best predictor was population density," Geary said. "And in fact, it seemed that there was very little change in brain size across our sample of fossil skulls until we hit a certain population size. Once that population density was hit, there was a very quick increase in brain size," he said. Looking at all the variables together allowed the researchers to "separate out which variables are really important and which variables may be correlated for other reasons," added Geary. While the climate variables were still significant, their importance was much lower than that of population density, he said. The results were published in the March 2009 issue of the journal Human Nature. Questions linger
The social competition hypothesis "sounds good," said Ralph Holloway, an anthropologist at Columbia University, who studies human brain evolution. But, he adds: "How would you ever go about really testing that with hard data?"
He points out that the sparse cranium data "doesn’t tell you anything about the differences in populations for Homo erectus, or the differences in populations of Neanderthals." For example, the number of Homo erectus crania that have been found in Africa, Asia, Indonesia and parts of Europe is fewer than 25, and represent the population over hundreds of thousands of years, he said.
"You can't even know the variation within a group let alone be certain of differences between groups," Holloway said. Larger skulls would be considered successful, but "how would you be able to show that these were in competition?"
However, Holloway is supportive of the research. "I think these are great ideas that really should be pursued a little bit more," he said.
Alternative hypotheses
Holloway has another hypothesis for how our brains got so big. He thinks that perhaps increased gestation time in the womb or increased dependency time of children on adults could have a played role. The longer gestation or dependency time "would have required more social cooperation and cognitive sophistication on the part of the parents," he said. Males and females would have needed to differentiate their social roles in a complementary way to help nurture the child. The higher level of cognition needed to perform these tasks could have led to an increase in brain size.
Still other hypotheses look at diet as a factor. Some researchers think that diets high in fish and shellfish could have provided our ancestors with the proper nutrients they needed to grow a big brain. And another idea is that a decreased rate of cell death may have allowed more brain neurons to be synthesized, leading to bigger noggins.
Ultimately, no theory can be absolutely proven, and the scant fossil record makes it hard to test hypotheses. "If you calculate a generation as, let's say, 20 years, and you know that any group has to have a minimal breeding size, then the number of fossils that we have that demonstrates hominid evolution is something like 0.000001 percent," Holloway said. "So frankly, I mean, all hypotheses look good."
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A great article from www.pakalertpress.comIsn’t it obvious that there is a significant global awakening happening? Just as the Mayans predicted so many years ago, the apocalypse would become apparent in 2012. But many misinterpret the apocalypse to be the end of the world, when in fact it actually means an “un-covering, a revelation of something hidden.”As many continue to argue the accuracy of the Mayan calendar, it can no longer be argued that a great many people are finally [...]
Friday, July 18, 2014, 12:24 PM - For over 75 years, tiny Pluto enjoyed its status as the most distant planet in our solar system, but in 2006, it was demoted down to a 'dwarf planet' and its title was passed on to Neptune. Now, though, the editor of Astronomy magazine is sounding the rallying cry to re-open the debate about Pluto's nature, which could potentially redefine what it means to be a planet.
In 2006, when the International Astronomical Union (IAU) set down an official definition for what a 'planet' is, they came up with three rules: 1) The object must be in orbit around the Sun, 2) The object must be massive enough to be a sphere by its own gravitational force. More specifically, its own gravity should pull it into a shape of hydrostatic equilibrium, and 3) It must have cleared the neighborhood around its orbit. Everything in the solar system technically orbits around the Sun, of course. Something like the Moon doesn't qualify, though, even though it's massive enough to be roughly spherical and its 'neighborhood' is as clear as Earth's is, because it only goes around the Sun as a consequence of being in orbit around Earth. Same goes for the moons of the other planets. Asteroids and comets don't qualify because they're not big enough to become spherical by their own gravity. Even Ceres (which is roughly spherical) doesn't make the cut, because it's in the asteroid belt, thus its 'neighborhood' isn't clear. Pluto suffers the same problem as Ceres. It's definitely in orbit around the Sun (or at least the common gravitational focus it shares with Charon is in orbit around the Sun). It is massive enough to be a sphere. It just isn't considered to have cleared its neighborhood. So, not a planet, at least by the IAU rules.
However, while the first two rules are pretty clear and easy to determine, third isn't. According to Prof. Abel Méndez, of the University of Puerto Rico at Arecibo, "there is no standard 'cleared' metric." It seems that due to the very existence of the Kuiper Belt, Pluto loses its status. However, exactly how cleared does the neighborhood have to be? There are millions of near-Earth asteroids flying around us, and there are even some asteroids that are locked into the same orbit as Earth ('Earth trojans'). There are even more asteroids near Mars' orbit, due to its proximity to the asteroid belt. Jupiter has an extremely large collection of asteroids in its orbit, both preceding it (the Greeks) and following behind (the Trojans). Even discounting these cases, as it is, when you go further out into the solar system, it gets harder and harder for an object to clear its neighborhood. This is simply because it makes fewer orbits around the Sun compared to objects closer to the Sun, and thus it encounters the other objects in its orbit far less often. Consider Earth, going around the Sun once every year, with Pluto orbiting every 247 years. So, whereas Earth has made roughly 4.5 billion trips around the Sun since it formed, Pluto has only made 18 million similar trips (if it formed at roughly the same time). As Astronomy magazine editor David Eicher said: "At the Pluto-like distance of 40 astronomical units — 40 times farther away from the Sun then we are now — Earth would not clear its orbit of asteroids, and so would Earth then not be classified as a planet?" Also, since recent evidence has pointed to the fact that there may be two super-Earth-sized objects out beyond Pluto, both of them would be considered 'dwarf planets' as well, despite one potentially being 10 times the mass of Earth and the other being up to 100 times the mass of Earth. So, when it comes to Pluto, what's the case for making it a planet again? Based on the facts above and Eicher's own thoughts: 1) the definition of what 'cleared the neighborhood around its orbit' is, itself, unclear 2) it seems unjustifiable that an object even larger than the Earth would not be considered a planet, simply because it orbits far out in our solar system 3) an object's intrinsic characteristics should dictate what kind of object it is, not its location. Indeed, if you take the IAU's definition and attempt to apply it to all objects we know about, the multitude of worlds that we've discovered outside our solar system aren't technically planets, despite being large enough and even if they've cleared their orbit, because they don't orbit around the Sun. So, perhaps it's time to revise the IAU's definition, not only to reconsider Pluto for planetary status, but also to make the definition applicable to a wider range of objects. Even if they changed the first rule to have 'a star' instead of 'the Sun' and changed the emphasis of the third rule to be that the object is large enough compared to the rest of the objects in its orbit to be capable of clearing its neighborhood (given enough time), it might be a much better set of conditions to measure everything against. As Astronomy's editors offer up their time and efforts to host a renewed debate about Pluto, what do you think about its status? Should it be a planet again, remain as a dwarf planet, or perhaps something else? Leave your ideas in the comments below.
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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.”
Spreading seeds of awareness on this site and within its many forms since 2006.
14 Annual Spins rounds Sol 071120
thank U Mission Control with the way of gratitude for the co-creation and presentation of every piece of information needed in order to complete this mission to disarm dysfunctional patterns Thank you and I’m grateful that I was able to help provide this resource to me and myself and all those who may have you sit and understand it and made it one day find resonate within your field of Attraction so that we may need to maybe get a team there I decided to take another job occupation of your next transition or whatever you choose to focus on next but thank you so much to all the support world-wise that she my homeboys and homegirls over in the Netherlands and Gaia and dr. Diana loopy Philip from France, Alison Maclean, Tolosa Diane Abigail the gfol federation’s confederations and I’ll local Earth groups, dashiki Niro’s the Blu-rays anybody who has been a contributor on this site directly or indirectly providing you help spread through email a different means information that will help raise and lift anybody by not telling him what to do and I appreciate you that I’m not the only religion that may be planting seeds and invited them to investigate for themselves and come to their own understanding and then have the ability to take ownership of their own creation through their own understanding that’s the siren Divinity is about and that’s why we were created to be enough to human beings are it’s time we finish his transition and stop playing games with our probability feels acting like what maybe I’ll be able to work around it there isn’t all roads lead to Rome in the end so he was a program eyelash it’s not going to your face and this is the truth of your life except it start creating from it responsibility for every creation you make all the way down to the thought that’s truly what it’s about we’re about to make a tremendous leap and jump so to speak, was kind of like when the universe itself has created this imagine I can’t even put it into words cuz I don’t have words given no Credence but I invite you I’m honored to have this experience I have one things I cannot even comprehend could cheap or contemplated are received before and it will definitely have any impact in my next transition are eBay’s Road focus on my next project but anyways thank you grateful 14 years they playing and at times her moment of reflection in celebration anytime the turbulence and frequency shift and lots of communication because they’re over there and you’re over here and you’re just too far apart there’s too much interference in between you because of the separation that’s occurring in our own evolutionary stages so many ways to love you like Battlefield thank you president and of course feels cool tribe.net the new entry for fun and have to cancel our society and that’s all I can pull off the top of my head right now in New Zealand and Australia especially the code writers who wrote text eons ago to speak to us right now today and I first had conversation is Remembrance and everybody involved with integrating new variables and help me decide collectively let the new 0 0 1 0 1 1 0 reality in our new home everything will be like more sooner than from here to there were already here there’s nowhere to go nowhere to be no way that she the only thing we have to do is be there now. InJoY!
NASA Ames/SETI Institute/JPL-Caltech
U.S. Creates Largest Protected Area in the World ~ 3X Larger than California
"We thought [the monument decision] was a good way to balance what the science was telling us was important to protect and the needs of those who use the area," Boots said.
The area being protected by the administration will expand the protected areas from 50 miles offshore to 200 miles offshore around three areas—Wake Island, Johnston Atoll, and Jarvis Island—the maximum reach of the United States’ exclusive economic zone. The current 50-mile offshore protections around the Howland and Baker islands, and Kingman Reef and Palmyra Atoll, will not change.
Kerry said one measure that could help deter illegal fishing in the region, as well as around the world, would be to implement the Port State Measures Agreement, an international treaty that requires member nations to prevent illegally caught fish from entering the market. Eleven nations or parties have ratified the agreement, but a total of 25 must sign before the treaty will take effect.
"Our goal is to get this done this year," Kerry said.