what is the ovality and how to find out it
Inside the dark heart of the Eagle
Inside the dark heart of the Eagle
Herschel has peered inside an unseen stellar nursery and revealed surprising amounts of activity. Some 700 newly-forming stars are estimated to be crowded into filaments of dust stretching through the image. The image is the first new release of ‘OSHI’, ESA’s Online Showcase of Herschel Images.
This image shows a dark cloud 1000 light-years away in the constellation Aquila, the Eagle. It covers an area 65 light-years across and is so shrouded in dust that no previous infrared satellite has been able to see into it. Now, thanks to Herschel’s superior sensitivity at the longest wavelengths of the infrared, astronomers have their first picture of the interior of this cloud.
It was taken on 24 October using two of Herschel’s instruments: the Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE). The two bright regions are areas where large newborn stars are causing hydrogen gas to shine.
The new OSHI website that goes live today will become the library of Herschel’s best images. Stunning views of the infrared sky will be made available as the mission progresses. Each will be captioned in a way to make them accessible to media representatives, educators and the public.
Embedded within the dusty filaments in the Aquila image are 700 condensations of dust and gas that will eventually become stars. Astronomers estimate that about 100 are protostars, celestial objects in the final stages of formation. Each one just needs to ignite nuclear fusion in its core to become a true star. The other 600 objects are insufficiently developed to be considered protostars, but these too will eventually become another generation of stars.
This cloud is part of Gould’s Belt, a giant ring of stars that circles the night sky – the Solar System just happens to lie near the centre of the belt. The first to notice this unexpected alignment, in the mid-19th century, was England’s John Herschel, the son of William, after whom ESA’s Herschel telescope is named. But it was Boston-born Benjamin Gould who brought the ring to wider attention in 1874.
Gould’s Belt supplies bright stars to many constellations such as Orion, Scorpius and Crux, and conveniently provides nearby star-forming locations for astronomers to study. Observing these stellar nurseries is a key programme for Herschel, which aims to uncover the demographics of star formation and its origin, or in other words, the quantities of stars that can form and the range of masses that such newborn stars can possess. Apart from this region of Aquila, Herschel will target 14 other star-forming regions as part of the Gould’s Belt Key Programme.
The scientific rights of these Herschel observations are owned by the consortium of the Gould Belt Key Programme, led by P. André (CEA Saclay). A total of 15 nearby star-forming regions such as Aquila will be studied as part of this Programme.
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Colliding Auroras Produce an Explosion of Light
A network of cameras deployed around the Arctic in support of NASA's THEMIS mission has made a startling discovery about the Northern Lights. Sometimes, vast curtains of aurora borealis collide, producing spectacular outbursts of light. Movies of the phenomenon were unveiled at the Fall Meeting of the American Geophysical Union today in San Francisco."Our jaws dropped when we saw the movies for the first time," said space scientist Larry Lyons of the University of California-Los Angeles (UCLA), a member of the team that made the discovery. "These outbursts are telling us something very fundamental about the nature of auroras."
The collisions occur on such a vast scale that isolated observers on Earth -- with limited fields of view -- had never noticed them before. It took a network of sensitive cameras spread across thousands of miles to get the big picture.
NASA and the Canadian Space Agency created such a network for THEMIS, short for "Time History of Events and Macroscale Interactions during Substorms." THEMIS consists of five identical probes launched in 2006 to solve a long-standing mystery: Why do auroras occasionally erupt in an explosion of light called a substorm?
Twenty all-sky imagers (ASIs) were deployed across the Alaskan and Canadian Arctic to photograph auroras from below while the spacecraft sampled charged particles and electromagnetic fields from above. Together, the on-ground cameras and spacecraft would see the action from both sides and be able to piece together cause and effect-or so researchers hoped. It seems to have worked.
The breakthrough came earlier this year when UCLA researcher Toshi Nishimura assembled continent-wide movies from the individual ASI cameras. "It can be a little tricky," Nishimura said. "Each camera has its own local weather and lighting conditions, and the auroras are different distances from each camera. I've got to account for these factors for six or more cameras simultaneously to make a coherent, large-scale movie."
The first movie he showed Lyons was a pair of auroras crashing together in Dec. 2007. "It was like nothing I had seen before," Lyons recalled. "Over the next several days, we surveyed more events. Our excitement mounted as we became convinced that the collisions were happening over and over."
The explosions of light, they believe, are a sign of something dramatic happening in the space around Earth-specifically, in Earth's "plasma tail." Millions of kilometers long and pointed away from the sun, the plasma tail is made of charged particles captured mainly from the solar wind. Sometimes called the "plasma sheet," the tail is held together by Earth's magnetic field.
The same magnetic field that holds the tail together also connects it to Earth's polar regions. Because of this connection, watching the dance of Northern Lights can reveal much about what's happening in the plasma tail.
THEMIS project scientist Dave Sibeck of NASA's Goddard Space Flight Center, Greenbelt, Md. said, "By putting together data from ground-based cameras, ground-based radar, and the THEMIS spacecraft, we now have a nearly complete picture of what causes explosive auroral substorms."
Lyons and Nishimura have identified a common sequence of events. It begins with a broad curtain of slow-moving auroras and a smaller knot of fast-moving auroras, initially far apart. The slow curtain quietly hangs in place, almost immobile, when the speedy knot rushes in from the north. The auroras collide and an eruption of light ensues.
How does this sequence connect to events in the plasma tail? Lyons believes the fast-moving knot is associated with a stream of relatively lightweight plasma jetting through the tail. The stream gets started in the outer regions of the plasma tail and moves rapidly inward toward Earth. The fast knot of auroras moves in synch with this stream.
Meanwhile, the broad curtain of auroras is connected to the stationary inner boundary of the plasma tail and fueled by plasma instabilities there. When the lightweight stream reaches the inner boundary of the plasma tail, there is an eruption of plasma waves and instabilities. This collision of plasma is mirrored by a collision of auroras over the poles.
National Science Foundation-funded radars located in Poker Flat, Alaska, and Sondrestrom, Greenland, confirm this basic picture. They have detected echoes of material rushing through Earth's upper atmosphere just before the auroras collide and erupt. The five THEMIS spacecraft also agree. Last winter, they were able to fly through the plasma tail and confirm the existence of lightweight flows rushing toward Earth.
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Quiet Sun Means Cooling of Earth’s Upper Atmosphere
New measurements from a NASA satellite show a dramatic cooling in the upper atmosphere that correlates with the declining phase of the current solar cycle. For the first time, researchers can show a timely link between the Sun and the climate of Earth’s thermosphere, the region above 100 km, an essential step in making accurate predictions of climate change in the high atmosphere.Scientists from NASA's Langley Research Center and Hampton University in Hampton, Va., and the National Center for Atmospheric Research in Boulder, Colo., presented these results at the fall meeting of the American Geophysical Union in San Francisco from Dec. 14 to 18.
Earth's thermosphere and mesosphere have been the least explored regions of the atmosphere. The NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) mission was developed to explore the Earth’s atmosphere above 60 km altitude and was launched in December 2001. One of four instruments on the TIMED mission, the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, was specifically designed to measure the energy budget of the mesosphere and lower thermosphere. The SABER dataset now covers eight years of data and has already provided some basic insight into the heat budget of the thermosphere on a variety of timescales.
The extent of current solar minimum conditions has created a unique situation for recent SABER datasets, explains Stan Solomon, acting director of the High Altitude Observatory, National Center for Atmospheric Research in Boulder, Colo. The end of solar cycle 23 has offered an opportunity to study the radiative cooling in the thermosphere under exceptionally quiescent conditions.
"The Sun is in a very unusual period," said Marty Mlynczak, SABER associate principal investigator and senior research scientist at NASA Langley. "The Earth’s thermosphere is responding remarkably — up to an order of magnitude decrease in infrared emission/radiative cooling by some molecules."
The TIMED measurements show a decrease in the amount of ultraviolet radiation emitted by the Sun. In addition, the amount of infrared radiation emitted from the upper atmosphere by nitric oxide molecules has decreased by nearly a factor of 10 since early 2002. These observations imply that the upper atmosphere has cooled substantially since then. The research team expects the atmosphere to heat up again as solar activity starts to pick up in the next year.
While this warming has no implications for climate change in the troposphere, a fundamental prediction of climate change theory is that the upper atmosphere will cool in response to increasing carbon dioxide. As the atmosphere cools the density will increase, which ultimately may impact satellite operations through increased drag over time.
The SABER dataset is the first global, long-term, and continuous record of the Nitric oxide (NO) and Carbon dioxide (CO2) emissions from the thermosphere.
"We suggest that the dataset of radiative cooling of the thermosphere by NO and CO2 constitutes a first climate data record for the thermosphere," says Mlynczak.
The TIMED data provide a climate record for validation of upper atmosphere climate models, which is an essential step in making accurate predictions of climate change in the high atmosphere. SABER provides the first long-term measurements of natural variability in key terms of the upper atmosphere climate.
"A fundamental prediction of climate change theory is that upper atmosphere will cool in response to greenhouse gases in the troposphere," says Mlynczak. "Scientists need to validate that theory. This climate record of the upper atmosphere is our first chance to have the other side of the equation."
James Russell III, SABER principal investigator and co-director of the Center for Atmospheric Sciences at Hampton University in Hampton, Va., agrees adding, "The atmosphere is a coupled system. If you pick up one end of the stick, you automatically pick up the other – they're intrinsically linked. To be as accurate as possible, scientists have to understand global change throughout the atmosphere."
As the TIMED mission continues, these data derived from SABER will become important in assessing long term atmospheric changes due to the increase of carbon dioxide in the atmosphere.
TIMED is the first mission in the Solar Terrestrial Probes Program within the Heliophysics Division in NASA's Science Mission Directorate in Washington.
Related Links:
› TIMED Mission
› SABER Instrument
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NASA Calculates a Carbon Budget for the State of California
While world organizations struggle to find a benchmark and tracking standards for greenhouse gas (GHG) emissions, NASA has been supporting California’s new carbon emissions inventory report, using its satellite imaging data and computer models of the state’s natural ecosystems.
Researchers report that in 2004, the state’s natural ecosystems absorbed as much carbon dioxide from the atmosphere as fossil fuel carbons emitted into the atmosphere. They also discovered that during periods of above normal rainfall, ecosystems trapped significant amounts of carbon dioxide from the atmosphere in forests and soils. For these reasons, researchers suggest the ecosystems should be more extensively protected and conserved, and their emissions be monitored as closely as fossil fuel sources of GHG emissions. The results, based largely on a computer model called the NASA-Carnegie Ames Stanford Approach (CASA), will be presented this morning at the 2009 American Geophysical Union Fall meeting in San Francisco.
"One way to facilitate emissions reductions is by using regional and national carbon budgets," explained Christopher Potter, senior research scientist at NASA Ames Research Center, Moffett Field, Calif., and author of this study. "California’s growing population and demand for all forms of energy make it essential to maintain an accurate and complete accounting of the state’s greenhouse emissions inventory," Potter added.
California’s population is more than 10 percent of the total population in the United States, and produces 13 percent of the U.S. gross domestic product, according to 2000 U.S. Census Bureau data. Because of its large population, the state also contributes significantly to global GHG emissions. If California was a country, it would rank among the top 20 national GHG emitters worldwide.
The carbon budget of a region is determined by the amounts of carbon dioxide and methane gases absorbed or released by “green” vegetative ground cover, as observed by NASA satellites. These fluctuations are important to quantify, because they originate from both natural and anthropogenic processes.
In California, the main sources of carbon dioxide emissions are energy consumption in commercial, residential, industrial, and transportation sectors, production of cement and lime, and waste treatment. The main sources of methane emission are derived from landfills and agricultural (principally livestock-based) systems.
Scientists believe that California’s carbon budget is of special interest because the state may represent a U.S. national carbon budget; both have diversified lands, similar consumption of natural resources, and urban lifestyles. Other similarities include a mix of fossil fuel emissions, alternative energy sources, and ecosystem sinks.
Each year, California is required by law to compile a new carbon emission inventory, which is conducted by the California Energy Commission and California’s Air Resources Board. To refine the state’s emission inventory, NASA was asked to provide NASA satellite imaging data and carbon models. To locate the largest ecosystem sources and carbon sinks in California, scientists used the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the NASA Terra satellite. The vegetation “greenness” data from the MODIS sensor was directly downloaded into the CASA ecosystem simulation model. Scientists used the data to estimate monthly variations in the accumulated biomass of wood and other plant materials, such as the accumulated dead leaf biomass transferred into soil carbon pools. Inventory data from the California Energy Commission also was used to model the carbon dioxide emissions from fossil fuel combustion and greenhouse gas emissions from agricultural lands throughout the state.
This project was funded by NASA as part of a long-term research program dedicated to understanding how human-induced and natural changes affect our global environment.
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Cato’s Pat Michaels on Copenhagen, says thankfully they won’t accomplish much of anything
Leading libertarian Global Warming critic Pat Michaels, predicts that Obama and his International Socialist allies will likely fail on all fronts at the summit.
From Fox News, Dec. 17, "With Climate Deal Up in Air, Obama Takes Lowered Expectations to Denmark":
"What we are seeing is the can being kicked down the road to the next meeting of parties" in Mexico, said Pat Michaels, a senior fellow in environmental studies at the libertarian Cato Institute. Michaels said he didn't believe Obama's appearance at the summit would accomplish much, making it "an injudicious use of fossil fuel."
You can read Pat Michaels regular columns at Cato.org
50-50 Chance of Climate Deal
The Guardian feels there is a 50-50 chance there will be a binding deal signed on Friday in Copenhagen. Temperaments and anxiety levels of diplomats and entire countries were analyzed.
Brown and Clinton yuk it up in Copenhagen
“So, deal or no deal? As 120 presidents and prime ministers sat down to eat at the Queen of Denmark’s palace in Copenhagen tonight, the chances of both appeared equally high. Or low.
Depending on your temperament, within 24 hours or so, the world will have a climate change agreement that should limit carbon emissions and restrict temperatures to a 2C rise; or the talks will fall apart and the chance of an agreement will be lost for ever.
Gordon Brown was upbeat, while the usually chipper climate secretary, Ed Miliband, was distinctly cooler. The Bangladeshi negotiators were optimistic, the Maldivians were anxious; China was saying nothing, and Poland was resisting the EU’s plans to increase its offer of emission cuts to 30%. Then European MEPs rode in to declare that the EU offer should be raised to 40% cuts.
Meanwhile, some people are anxiously and cautiously optimistic. Here is another person who sees a ray of light, the representative from the WWF. Just 24 hours to go and WWF’s Head of Delegation Kim Carstensen is feeling more optimistic than he did a day ago. (video after the break)
He feels we have all been removed from the Valley of Death. That’s quite a statement, and some of that removal was due to Hillary Clinton. After her statement (see post below this for video) that included a possible promise of $100 billion in 2020 for the world’s poor countries (contingent upon open and verifiable emissions cuts in other countries), China also moved a bit, which was good news. Friday is the last day of the summit, and there will either be a deal or not, but the world will go on turning either way.
Then maybe we can all work on eco-socialism instead of moving money around from rich to poor countries, who should not have to beg for this help. The poor countries are as firmly attached to the planet and under the same dome of our polluted atmosphere as the rich countries. We all have an equal stake in fixing the climate, we all breath the same air, and this is why ’smoking sections’ in restaurants never worked.
More good Copenhagen videos here.
Obama to give NASA an extra $1B? | Bad Astronomy
The Science magazine blog is quoting unnamed sources who say that Obama, after a meeting with NASA Administrator Charles Bolden, has pledged $1 billion to NASA in 2011 to work on a heavy lift rocket to take astronauts to the Moon and Mars.
If this is true, that’s very interesting news indeed. I’ll stress that I personally look at this as unconfirmed leaked info, so take it with a grain of salt. Science is saying it’ll be announced officially as early as next week, or as late as the State of the Union address in January. If it is true, it comes on top of a more than $900 million bump by Congress for next year (which is official).
The report is unclear about some things, like what happens to the Constellation program to build Ares rockets. A lot of people in the space business (but outside of NASA) say the Ares 1-X test recently amounted to little more than fraud. Buzz Aldrin is one of them (note: Link to Huffington Post). I have heard the same from the Space Frontier Foundation as well. Dropping Ares-1, as Science is reporting might happen, is maybe not a bad thing. But what about the next generation rocket, the Ares V? That’s not mentioned, but I would expect that would be ditched too.
Here’s the money shot:
According to knowledgeable sources, the White House is convinced that scarce NASA funds would be better spent on a simpler heavy-lift vehicle that could be ready to fly as early as 2018. Meanwhile, European countries, Japan, and Canada would be asked to work on a lunar lander and modules for a moon base, saving the U.S. several billion dollars. And commercial companies would take over the job of getting supplies to the international space station.
I suspect this would be very good news indeed. Still and all, I note two things: 1) private companies still have not put much into orbit, so it’s premature to know how well they will do (though I have very high hopes, especially for SpaceX), and 2) just to reinforce this, this story is not yet confirmed.
So my take on this is wait and see. I have my opinions about space travel, but I lack the experience in this field to know specifically what is best for NASA and what is best for space exploration. I’ll be very interested to hear what others in the business have to say.
Soaring Pessimism Alters Views of Copenhagen
The following video was apparently made on December 15th. Copenhagen is full of lots of “fed up” people with hugely unresolved issues on various topics in Copenhagen. Are they helping or getting in the way of climate negotiations?
No one has tried harder to keep the human toll of climate change at the forefront than DemocracyNow and people like Naomi Klein. Unfortunately they are also the most cynical and pessimistic about the hundreds of conversations and negotiations that we are engaged in at Copenhagen and can’t see a single bright point anywhere. At this point, it’s easy to vent frustration about it and throw in the towel completely but I can’t see how that helps anyone. Even if all this convention does is to end deforestation in critical forests, it’s been worth something. It will take months to decide just what it has all accomplished, but it’s obvious now that the Copenhagen summit was never designed to “save the world”. I think it was overhyped. Too-high expectations are no doubt contributing to its ultimate “failure”. There will be future conferences and agreements on climate change.
The pessimistic cynicism reached a peak the other day when Klein said that Obama should “not bother” going to Copenhagen, mainly because the U.S. is harming the process, and wasting an opportunity. I’m sure Hillary’s “extraordinarily manipulative” announcement about financing didn’t help her mood. Here is Clinton’s announcement on possible $100 billion in financing, from Thursday morning.
Of course, everyone in government, and probably every single speech-giver at the conference is “manipulative”. So is Klein herself. So what? It strikes me as juvenile and counter-productive to dwell on that at this point. But then, Naomi Klein has disliked Clinton for a long time. Now she is turning on Obama. I’m still holding out some optimism that Obama will wake up and do the right thing just in the nick of time, but then, I have a belief in superheros that is quite unhealthy. The point is, pessimism certainly doesn’t help. It can even shorten your life. Klein isn’t going to last long at this rate.
This morning on DemocracyNow, Klein, a DM favorite, was summed up like this:
“And here’s a second segment, in which Klein calls out Secretary of State Hillary Clinton’s extraordinarily manipulative announcement from Copenhagen today that the US will contribute to a $100 billion dollar fund only if all UN member states reach a US-approved consensus–and declares it “blackmail.”
See both segments at The Nation here.
Not quite pessimistic enough, she was heard telling Obama to stay home.
“The US has lowered the bar and set goals so low, it’s been destructive. I think it would be better if the US had continued to stay out of it. I don’t see any point in US politicians coming here.”
She said.
OK, but that also accomplishes nothing. So what do pessimists suggest? Ultimately — survival.
But if that is your “solution” then why go to Copenhagen in the first place, obviously [...]
Navigenics for 23andMe prices?
Yes, That is correct. As if this stuff couldn't get any cheaper. It does.
"Happy, healthy holidays! Holiday offer: Our #genetic service for $499 (half off). Use code naviholiday2009 at checkout. http://bit.ly/roe95"
That straight from the mouths of the Navigenics Babes, Seriously. Do you know Katie Kihourany?
Everyone including Daniel MacArthur is yelping about the DeCodeMe free analysis offer, but I have yet to hear anyone screming about the 500 USD drop in price of Navigenics service. Ladies and Gentlemen, this is a 50% price cut.
In what world do you cut your service cost in half? This didn't even happen with the iPhone. Seriously?
This is a bad, bad sign coming from the team at Navigenics. Nearly a year ago they launched Annual Insight for 499.....Now the whole ship is up for 499........
I have yet to see how this market is the market for Whole Genome Testing. In fact, my assessment is that whole genome sequencing will not be used widely until it costs less than 300 USD.
Why? Can your genome data play crazy videos of Will Smith? What about making a phone call and downloading songs? No?
Well, what can a whole genome do for you? Good question. The iPhone wins because in it's ads it shows you what it can do......
These tests and the whole genome have not shown that utility. That's why they are cutting their costs.....because the can't show that they have use........
And that is precisely why deCode is offering its analysis service for free. They want to show you what they do........
The Sherpa Says: Like I said before, climbing Everest with one Crampon a windbreaker and a map is not what most rational people want to do......
Space tourism as “the final undiscovered frontier”?
A survey released yesterday by World Travel Market, a UK-based travel industry event organization, offers a somewhat pessimistic take on the space tourism market. The study, based on a poll of 1,030 Britons who took a summer vacation in 2009, found that only 27% said they would be interested in traveling into space; 50% said they were not and 23% said they might be interested. In addition, 74% said “they feared space travel would remain too expensive and exclusively for the super rich”, and only 4% thought it would became an “affordable mass-market travel product” within 30 years.
The numbers at first glance don’t sound promising: the press release leads off by claiming that “price concerns are turning holidaymakers off from becoming space tourists”. However, the numbers aren’t that surprising. First of all, the poll doesn’t appear to have limited their polling to people with the means to pay for a spaceflight at currently-planned prices. Second, the numbers aren’t that different from previous polls that did put such limits on respondents: for example, the 2002 Futron/Zogby poll found that 19% of people with the means to pay for a space tourism flight were either “definitely” or “very” likely to take a suborbital spaceflight (a number that rose to 28% when given a more rosy description of such a flight). Even that more pessimistic number resulted in a forecast of thousands of potential tourists a year after just a few years of operation.
“It’s disappointing holidaymakers fear they will be priced out of becoming space tourists,” Fiona Jeffery, chairman of World Travel Market, said in the release. “However, I’m confident the price will drop dramatically the more space tourism takes off.” Even if there isn’t a dramatic drop in prices, though, there’s still a potentially lucrative market to be tapped.
Orion Propulsion acquired
Any entrepreneurial venture, space or otherwise, needs an exit strategy: how those who invested into the company get their money back (plus, hopefully, a healthy return on that investment). These days that means, primarily, an acquisition by a larger company, given the difficulties of going public. The emerging NewSpace field has only seen a few such deals: Northtop Grumman’s purchase of Scaled Composites in 2007, Space Adventures acquisition of Zero-G Corporation in 2008, and Sierra Nevada Corporation’s purchase of SpaceDev, which took place one year ago today.
Yesterday saw another such deal: Huntsville-based Dynetics annoucned it was acquiring Orion Propulsion, a small developer of rocket propulsion systems, for an undisclosed sum. Tim Pickens, who founded Orion in 2004, will now become “chief propulsion engineer” for Dynetics, a company that does space as part of a broader portfolio that includes information techology, automotive, and other fields. It’s also become a home for some former NASA officials: former NASA Marshall Space Flight Center director David King joined Dynetics in May as executive vice president, while Steve Cook, who managed the Ares program at Marshall, became director of space technologies at Dynetics in September.
Orion Propulsion, founded by Pickens after he returned to Alabama after working at Scaled to design the hybrid propulsion system for SpaceShipOne, has worked on a variety of government and commercial projects. This includes roll and reaction control systems for the Ares 1 to the forward propulsion system for Bigelow Aerospace’s Sundancer module. The latter system is designed to be a “green” system, using hydrogen and oxygen generated from water water: “burning urine”, as Pickens put it during a presentation at the 2009 ISDC in Orlando in May.
Solar Storms and Radiation Exposure on Commercial Flights
Scientists at NASA’s Langley Research Center have completed a first attempt to accurately calculate the level of damaging radiation flight crews and passengers are exposed to on commercial airline flights. The work is an early step toward developing a model to observe radiation exposure for all commercial flights, particularly for pilots and crews who spend their careers airborne and who are at greater risk of developing certain cancers.The study considered not only everyday radiation emanating from space, but also the additional energy unleashed during a solar storm, which can be profound. NASA scientists say not including geomagnetic effects on solar radiation in modeling radiation exposure could underestimate the dosage by 30 to 300 percent.
Researchers looked at passengers and crew on typical flights from Chicago to Beijing, Chicago to Stockholm and London to New York, during what is known as the Halloween 2003 Storm. These flights were chosen because of their long flight paths near the North Pole, where the Earth’s natural protection from radiation is weakest. Earth’s magnetic field approaches zero above the poles. The Halloween 2003 event was chosen because it was both a large and a complex storm, making it a good test for the model.
The study found that aircrew and passengers during the Chicago to Beijing flight, for example, would have been exposed to about 12 percent of the annual radiation limit recommended by the International Committee on Radiological Protection. But these exposures were greater than on typical flights at lower latitudes, and confirmed the concerns about commercial flights at high latitudes.
“The upshot is that these international flights were right there at that boundary where many of these events can take place, where radiation exposure can be much higher,” said Chris Mertens, senior research scientist at NASA’s Langley Research Center, who is leading the research effort. Mertens will present his latest results at the American Geophysical Union fall meeting in San Francisco on Dec. 16.
Piecing together the radiation exposure on these typical flights is the first step toward developing a real-time system that researchers hope will become a standard component of commercial airline cockpits. Radiation exposure could one day be taken into account in the same way weather conditions are considered before deciding to fly or deciding what exact route to fly and at what altitude.
Flying above and beyond Earth’s natural protection
The number of international flights that skirt the north pole are increasing. Airlines save massive amounts of fuel on flights such as Chicago-to-Shanghai by simply flying “over the top” – it is a far shorter route than following the latitude lines. But while saving fuel, these flight paths take planes and their passengers to the thinner layers of Earth’s magnetosphere, which shields potentially harmful solar and cosmic radiation.
On a typical day, the Sun is quiet and “background radiation,” the cumulative effect of radiation from cosmic sources reaching Earth, is the only other source. But when the Sun is not quiet, violent storms on the star’s surface eject powerful bursts of radiation to the Earth. It is these events that have never been truly accounted for in studies of how much radiation pilots and airline passengers are exposed to.
Pilots Await Results
While the flights studied appear to have not put passengers in danger of exceeding the safe radiation limit in an individual flight, concerns remain, Mertens said. Many workers whose jobs expose them to consistent radiation sources log that exposure to keep a record over one’s career. People who work on commercial airline flights are technically listed as “radiation workers” by the federal government – a classification that includes nuclear plant workers and X-ray technicians. But unlike some others in that category, flight crews do not quantify the radiation they are exposed to.
Mike Holland, an American Airlines captain and vice chairman for radiation and environmental issues with the Allied Pilots Association, said he is following Mertens’ research with interest. The pilots association has written a formal letter in support of the research. Holland cited studies that show pilots face a four-times greater risk of melanoma than the general population. But because pilots and flight crews do not wear radiation-measuring badges like other radiation workers, the only estimates about their career-long exposure come from models.
Up until now, most of those models only attempted to capture the amount of cosmic background radiation that reaches airliners in flight. Holland said he believes including solar radiation, especially during solar storms, is important. He looks forward to having answers for the pilots who contact him with questions about radiation and cancer risk.
“When I talk to epidemiologists, they have two questions for me: What is your exposure? And what is your health for 20 to 30 years after you retire?” Holland said. The second question he and other pilots can answer, in time. But as of now, they can’t measure their exposure.
“We’re excited that Chris is doing this,” Holland said, “and we hope it can answer the epidemiologists first question, which is, ‘What is your exposure?’”
Related Links:
> NAIRAS at Space Environment Technologies
> Advanced Satellite Aviation Weather Products (ASAP)
> NASA's Applied Sciences Program
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Global Digital Elevation Model
This Global Digital Elevation Model, or GDEM, is a product of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), a joint program of NASA and Japan's Ministry of Economy, Trade and Industry. The image was released on June 29, 2009, and was created by processing and stereo-correlating the 1.3 million-scene ASTER archive of optical images, covering Earth's land surface between 83 degrees North and 83 degrees South latitudes. The GDEM is produced with 98-feet postings, and is formatted as 23,000 one-by-one-degree tiles. In this colorized version, low elevations are purple, medium elevations are greens and yellows, and high elevations are orange, red and white.
With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 50 to 300 feet, ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite.
The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change.
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Hubble’s Festive View of a Grand Star-Forming Region
NASA, ESA, and F. Paresce (INAF-IASF, Bologna, Italy), R. O'Connell (University of Virginia, Charlottesville), and the Wide Field Camera 3 Science Oversight Committee.
› Larger image
› Larger image
Just in time for the holidays: a Hubble Space Telescope picture postcard of hundreds of brilliant blue stars wreathed by warm, glowing clouds. The festive portrait is the most detailed view of the largest stellar nursery in our local galactic neighborhood.
The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. There is no known star-forming region in our galaxy as large or as prolific as 30 Doradus.
Many of the diamond-like icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun. These hefty stars are destined to pop off, like a string of firecrackers, as supernovas in a few million years.
The image, taken in ultraviolet, visible, and red light by Hubble's Wide Field Camera 3, spans about 100 light-years. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the stars' birth and evolution.
The brilliant stars are carving deep cavities in the surrounding material by unleashing a torrent of ultraviolet light, and hurricane-force stellar winds (streams of charged particles), which are etching away the enveloping hydrogen gas cloud in which the stars were born. The image reveals a fantasy landscape of pillars, ridges, and valleys, as well as a dark region in the center that roughly looks like the outline of a holiday tree. Besides sculpting the gaseous terrain, the brilliant stars can also help create a successive generation of offspring. When the winds hit dense walls of gas, they create shocks, which may be generating a new wave of star birth.
The movement of the LMC around the Milky Way may have triggered the massive cluster's formation in several ways. The gravitational tug of the Milky Way and the companion Small Magellanic Cloud may have compressed gas in the LMC. Also, the pressure resulting from the LMC plowing through the Milky Way's halo may have compressed gas in the satellite. The cluster is a rare, nearby example of the many super star clusters that formed in the distant, early universe, when star birth and galaxy interactions were more frequent. Previous Hubble observations have shown astronomers that super star clusters in faraway galaxies are ubiquitous.
The LMC is located 170,000 light-years away and is a member of the Local Group of Galaxies, which also includes the Milky Way.
The Hubble observations were taken Oct. 20-27, 2009. The blue color is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, and is an International Year of Astronomy 2009 program partner.
Images and more information are available at:
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Deposits in Martian Trough Point to Complex Hydrological Past
Variations in composition of light-toned deposits in troughs on Mars suggest a diversity of water-related processes, based on analysis of observations by NASA's Mars Reconnaissance Orbiter.View this site car shipping
NASA Outlines Recent Greenhouse Gas Research
Researchers studying carbon dioxide, a leading greenhouse gas and a key driver of global climate change, now have a new tool at their disposal: daily global measurements of carbon dioxide in a key part of our atmosphere. The data are courtesy of the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft. Moustafa Chahine, the instrument's science team leader at NASA's Jet Propulsion Laboratory, Pasadena, Calif., unveiled the new product at a briefing on recent breakthroughs in greenhouse gas, weather and climate research from AIRS at this week's American Geophysical Union meeting in San Francisco. The new data have been extensively validated against both aircraft and ground-based observations. They give users daily and monthly measurements of the concentration and distribution of carbon dioxide in the mid-troposphere--the region of the atmosphere located between 5 and 12 kilometers, or 3 to 7 miles, above Earth's surface, and track its global transport. Users can also access historical AIRS carbon dioxide data spanning the mission's entire seven-plus years in orbit. The product represents the first-ever release of global daily carbon dioxide data that are based solely on observations.
"AIRS provides the highest accuracy and yield of any global carbon dioxide data set available to the research community, now and for the immediate future," said Chahine. "It will help researchers understand how this elusive, long-lived greenhouse gas is distributed and transported, and can be used to develop better models to identify 'sinks,' regions of the Earth system that store carbon dioxide. It's important to study carbon dioxide in all levels of the troposphere."
Chahine said previous AIRS research data have led to some key findings about mid-tropospheric carbon dioxide. For example, the data have shown that, contrary to prior assumptions, carbon dioxide is not well mixed in the troposphere, but is rather "lumpy." Until now, models of carbon dioxide transport have assumed its distribution was uniform.
Carbon dioxide is transported in the mid-troposphere from its sources to its eventual sinks. More carbon dioxide is emitted in the heavily populated northern hemisphere than in its less populated southern counterpart. As a result, the southern hemisphere is a net recipient, or sink, for carbon dioxide from the north. AIRS data have previously shown the complexity of the southern hemisphere's carbon dioxide cycle, revealing a never-before-seen belt of carbon dioxide that circles the globe and is not reflected in transport models.
In another major finding, scientists using AIRS data have removed most of the uncertainty about the role of water vapor in atmospheric models. The data are the strongest observational evidence to date for how water vapor responds to a warming climate.
"AIRS temperature and water vapor observations have corroborated climate model predictions that the warming of our climate produced as carbon dioxide levels rise will be greatly exacerbated -- in fact, more than doubled -- by water vapor," said Andrew Dessler, a climate scientist at Texas A&M University, College Station, Texas.
Dessler explained that most of the warming caused by carbon dioxide does not come directly from carbon dioxide, but from effects known as feedbacks. Water vapor is a particularly important feedback. As the climate warms, the atmosphere becomes more humid. Since water is a greenhouse gas, it serves as a powerful positive feedback to the climate system, amplifying the initial warming. AIRS measurements of water vapor reveal that water greatly amplifies warming caused by increased levels of carbon dioxide. Comparisons of AIRS data with models and re-analyses are in excellent agreement.
"The implication of these studies is that, should greenhouse gas emissions continue on their current course of increase, we are virtually certain to see Earth's climate warm by several degrees Celsius in the next century, unless some strong negative feedback mechanism emerges elsewhere in Earth's climate system," Dessler said.
Originally designed to observe atmospheric temperature and water vapor, AIRS data are already responsible for the greatest improvement to five- to six-day weather forecasts than any other single instrument, said Chahine. JPL scientists have shown a major consequence of global warming will be an increase in the frequency and strength of severe storms. Earlier this year, a team of NASA researchers showed how AIRS can significantly improve tropical cyclone forecasting. The researchers studied deadly Typhoon Nargis in Burma in May 2008. They found the uncertainty in the cyclone's landfall position could have been reduced by a factor of six had more sophisticated AIRS temperature data been used in the forecasts.
AIRS observes and records the global daily distribution of temperature, water vapor, clouds and several atmospheric gases including ozone, methane and carbon monoxide. With the addition of the mid-tropospheric carbon dioxide data set this week, a seven-year digital record is now complete for use by the scientific community and the public.
For more on AIRS, see http://airs.jpl.nasa.gov/ .
JPL is managed for NASA by the California Institute of Technology in Pasadena.
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Unexpected Wheel-Test Results
Diagnostic tests were run on Spirit's right-rear wheel and right-front wheel on Sol 2013 (Dec. 12, 2009). The right-rear wheel, which stalled during a drive two weeks earlier, continued to show no motion in the latest tests and exhibited very high resistance in the motor winding. The right-front wheel, which stopped operating on Sol 779 (March 13, 2006), surprised engineers by indicating normal resistance and turning slightly during a resistance test for that wheel. Small motion is expected during an electrical resistance test for an operating actuator, but the right-front actuator was expected to be non-operational. The right-front wheel was last checked just after its apparent failure in 2006 and at that time indicated an open circuit. Although no clear theory for failure had been established, the failure was generally regarded as permanent. It is important to remember that the Sol 2013 test of the right-front wheel was only a rotor resistance test, and no conclusions can be drawn at this point without further testing.
The plan for Spirit on Sol 2116 (Dec. 15) is to command a drive. This drive will further investigate functionality of the right-front and right-rear wheels. The results are expected Wednesday.
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New Results from a Terra-ific Decade in Orbit
December 18, 2009, marks the tenth year since the launch of Terra, one of NASA's "flagship" Earth observing satellites. But the decade is more than just a mechanical milestone. With each additional day and year that the satellite monitors Earth, scientists achieve a lengthened record of Earth's vital signs. It's that record that helps scientists assess the health of Earth's ocean, land, and atmosphere, and determine how these systems are changing."Earth system science is a relatively young science," said Marc Imhoff, project scientist for the mission and a researcher at NASA's Goddard Space Flight Center in Greenbelt, Md. "Terra's sensors have provided the first coordinated set of observations allowing us to link Earth system processes across space and time so we can better understand how they function together and how we interact with them."
Since Terra's five instruments officially saw "first light" on Feb 24, 2000, after a post-launch checkout, the data have continued to advance Earth system science. Here's a sample of the latest developments to be presented by Terra researchers at the Fall Meeting of the American Geophysical Union in San Francisco.
Droughts Slow Earth's Carbon Metabolism
Data from Terra's Moderate Resolution Imaging Spectroradiometer (MODIS) have turned up evidence that climate change may have negative effects for ecosystems earlier than we thought, according to Maosheng Zhao, an ecologist at the University of Montana in Missoula.
For the past several decades, photosynthesis by land plants and trees has absorbed, or acted as a "sink," for about one third of global carbon dioxide emissions, helping to slow the increase of the greenhouse gas in the atmosphere. But scientists have found that global carbon uptake by land plants is declining.
"This decreasing trend has very important implications for how much and how long humans should count on the carbon sink capacity of terrestrial ecosystems," Zhao said.
To arrive at their finding, Zhao and colleagues analyzed MODIS data from 2000 to 2008. Directly measuring carbon dioxide from space is difficult, so scientists rely on sensors to measure the photosynthetic activity of plants. That activity can then be translated to an estimate of how much carbon dioxide the plants are absorbing. "So far, MODIS is the best sensor we have for monitoring global vegetation dynamics," Zhao said.
A closer look reveals that carbon uptake is still on the rise in middle and high latitudes of the northern hemisphere. But that benefit is outweighed by changes in the tropics and southern hemisphere, where scientists observed less carbon being absorbed.
Zhao thinks that a major cause of the decrease is warming-related droughts, which impact crop yields, timber production, and expanses of natural vegetation.
Some computer models have predicted that by the middle of this century, carbon-climate feedbacks could cause terrestrial ecosystems to shift from being carbon sinks to sources, according to Zhao. "Our result is an early warning that we must take some actions to mitigate human-induced climate change."
Natural Hazards Tracked
There's no escaping the risk to human populations posed by natural hazards. But for almost 10 years, Terra has helped governments and local groups respond to and mitigate the consequences.
Just last month in El Salvador, Hurricane Ida brought heavy rains that triggered flooding and deadly mudslides. In another incident in November, a major algal bloom in Guatemala's Lake Atitlan had residents concerned about the lake's health and the safety of people who swim in and drink the water.
To help monitor these hazards, local governments and data processing groups turn to NASA for images from Terra's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER ). The instrument's spatial resolutions of about 15 to 90 meters produce detailed maps of land surface characteristics such as temperature, reflectance and elevation, which are key for helping decision-makers determine where and how to respond.
"The request for the mudslide and algal bloom images are typical of the types of requests we receive," said Michael Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We also work with the U.S. Forest Service to image active wildfires for logistical support and often for post-fire damage assessment and mitigation."
Instrument operators can point ASTER -- an instrument provided by Japan's Ministry of Economy Trade and Industry -- at specific targets and acquire about 500 images per day. Each day about 3,000 requests are active in the request database, ranging from field work, global maps, and regional monitoring. To decide where to point the instrument, an algorithm was developed to automatically prioritize requests.
For example, immediate threats such as the requests from El Salvador's Civil Protection Agency to monitor the flooding and mudslides and Guatemala's Ministry of Agriculture to monitor the algal bloom, receive higher priority. Lower priority targets include a project to obtain complete global maps of ASTER imagery at least 3-5 times during mission.
As part of its monitoring of natural hazards, ASTER has been keeping a long-term eye on more than 1,000 active volcanoes around the world. The extended archive will be used by researchers to characterize the historical behavior for each volcano.
"To improve prediction, we need to know which signals are important," Abrams said.
Pollution Travels High and Far
The Station wildfire that burned southern California in late August 2009 was the largest fire in the recorded history of Los Angeles County and its Angeles National Forest, with more than 160,577 acres burned. Pollution created by the wildfire traveled even further. Rising more than 4 miles (7 kilometers) above Earth's surface, smoke from the fire was carried over Nevada, Utah, and Colorado, and carbon monoxide from the fire traveled at least as far as Louisiana.
The measurement of smoke height was possible with Terra's Multiangle Imaging SpectroRadiometer (MISR ), which can resolve atmospheric components -- such as, clouds, dust and smoke plumes -- in three dimensions. MISR can also measure horizontal winds.
Scientists have used the instrument to develop a multi-year "climatology" or statistical database of the heights to which wildfires inject smoke into the atmosphere. The database now contains observations from more than 7,000 smoke plumes in North America, Siberia, and Africa.
"We discovered that for about one-fifth of wildfires, the smoke particles escape the low, turbulent part of the atmosphere and rise to a higher altitude, where they can remain concentrated for long periods and also be transported great distances " said David Diner, MISR principal investigator at JPL.
Researchers studying the dispersal of particulates from wildfires, volcanoes, and dust storms also use the data to test theoretical simulations against observed behavior. These simulations will help researchers understand, for example, what the effect of more fires in a warmer climate might have on air quality.
Other scientists are watching pollution that travels even greater distances, across international boundaries. Measurements of carbon monoxide from the Measurements of Pollution in the Troposphere instrument MOPITT -- provided by the Canadian Space Agency -- and of aerosols from the MISR and MODIS instruments allow scientists to observe both the sources and transport of pollution on a global scale.
"The Terra satellite made it possible to track pollution plumes as they are transported across the ocean, allowing us to observe numerous plumes of Asian pollution transported to the United States," said Daniel Jacob, an atmospheric scientist at Harvard University in Cambridge, Mass. "The findings show that air pollution is a global issue, and thus that meeting air quality goals in the United States will increasingly require international cooperation."
Balancing the Energy Budget
As society considers carbon dioxide caps and geoengineering, open questions remain 
about exactly how, why, and where Earth is warming. Answering those questions requires a clear picture of how the Earth's energy budget is changing.
For a decade, researchers using the Clouds and the Earth's Radiant Energy System (CERES) experiment on Terra have been taking stock of how much solar energy is absorbed by the planet's atmosphere and surface, and how much infrared and heat energy is emitted back into space. CERES scientists also study how cloud properties influence the energy exchange from space to the atmosphere to the ground and back again.
"CERES has provided a decade of accurate observations that allow us to explore changes over time, to see how radiation at the top of the atmosphere varies seasonally and annually," said Kevin Trenberth, A CERES investigator from the National Center for Atmospheric Research in Boulder, Colo. "The longer the record, the more valuable it becomes."
The observations have shown that the world is cloudier than we thought, and changes in cloudiness can lead to regional and global fluctuations in the heat budget. For instance, albedo is decreasing in the Arctic as snow and sea ice melt, but there is also evidence of compensation from an increase in cloud cover.
Researchers including Norman Loeb of NASA's Langley Research Center, Hampton, Va., and principal investigator for the CERES instrument, have found that measurements of the energy budget from space correlate well with what is being observed by heat content observations in the ocean, where most solar heat retained by Earth is stored.
Most strikingly, the CERES science team has updated the numbers in the planetary budget ledger and found a gap between incoming and outgoing radiation. The Earth is estimated to be absorbing at a rate of about 0.9 Watts per square meter more than it is emitting -- large enough to provoke the question: what does it mean for climate change?
"Terra has allowed us to observe cloud heights with MISR; cloud density and coverage, with MODIS, as well as sea ice, glaciers and surface temperatures; and incoming and outgoing radiation with CERES," said Marc Imhoff, project scientist for Terra. "That's a very powerful combo for understanding how the atmosphere, land, and oceans work together in balancing heat."
Related AGU talks
Wednesday, Dec. 16
U31C-01 Tracking Earth's global energy
U31C-05 Terra at 10: CERES Results
U32A-01 Geological mapping and hazards monitoring using ASTER data
U32A-02 Using Terra observations to quantify sources and intercontinental transport of pollution
U32A-04 MISR at 10: Looking back, ahead, and in between
U32A-07 Variations and trends of terrestrial primary production observed by MODIS
Related links:
NASA's American Geophysical Union homepage
› http://www.nasa.gov/topics/earth/agu/index.html
Related story: Terra details urban heat islands
› http://www.nasa.gov/mission_pages/terra/news/heat-islands.html
Terra Tracks Ten Years of Change
› terra.nasa.gov/Ten
Terra: The EOS Flagship
› terra.nasa.gov
About Terra
› earthobservatory.nasa.gov/Features/AM1
World of Change
› earthobservatory.nasa.gov/Features/WorldOfChange
Landslides in El Salvador
› earthobservatory.nasa.gov/NaturalHazards/view.php?id=41365
Drought Cycles in Australia
› earthobservatory.nasa.gov/Features/WorldOfChange/australia.php
Tracking Nature's Contribution to Pollution
› earthobservatory.nasa.gov/Features/ContributionPollution
Climate and Earth's Energy Budget
› earthobservatory.nasa.gov/Features/EnergyBalance
Seasonal Changes in Global Net Radiation
› earthobservatory.nasa.gov/IOTD/view.php?id=35555
Earth's Energy Budget Animations
› svs.gsfc.nasa.gov/vis/a010000/a010300/a010395/index.html
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