News this Week

Science  08 Jul 2011:
Vol. 333, Issue 6039, pp. 140

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  1. Around the World

    1 - Paris
    Shuffle Results in New Research Minister
    2 - South Korea
    Korean Students Are Top Digital Readers
    3 - Sacramento, California
    State Universities Reeling After More Cuts
    4 - Darmstadt, Germany
    Scientists Reconnect With Cluster Mission
    5 - Zagreb, Croatia
    Medical Journal Editors Resign Amid Acrimony


    Shuffle Results in New Research Minister


    The arrest in New York City of former International Monetary Fund (IMF) Managing Director Dominique Strauss-Kahn on charges of sexual assault has had a ripple effect in the French cabinet. As a result, France has a new minister for higher education and research.

    After finance minister Christine Lagarde replaced Strauss-Kahn as IMF chief on 29 June, Valérie Pécresse, who had held the research post for 4 years, was appointed junior budget minister and government spokesperson. Her place was in turn filled by Laurent Wauquiez, formerly in charge of European affairs. Wauquiez, who at 36 is the youngest member of the cabinet, studied history, English, German, and Arabic, and graduated from two of France's most elite higher education institutions, the École Normale Supérieure and the École Nationale d'Administration.

    Bertrand Monthubert, national secretary for higher education and research of the opposition French Socialist Party, calls Wauquiez a surprising choice. He will have “a tough job quelling the research and academic communities' deep fears for the future,” Monthubert says.

    South Korea

    Korean Students Are Top Digital Readers

    South Korean teenagers beat out their peers from 18 other countries in the first assessment of digital literacy. The Paris-based Programme for International Student Assessment (PISA) added a computer component to its 2009 reading test for 15-year-olds, and Korea chalked up a score of 568, 31 points above New Zealand and Australia and 49 points ahead of Japan. The average was 500. (The United Kingdom, Germany, and the United States did not participate.) Girls scored higher than boys in every country—an average of 24 points overall—but the difference was less marked than in assessments of print reading. One surprising finding: Greater use of the computer at home didn't necessarily translate into a better score.

    The digital assessment measured a student's ability to follow hyperlinks to obtain information on, for example, how to find a summer job. The test is part of a plan to expand PISA beyond pencil-and-paper assessments; future assessments will include computer-based tests of problem-solving skills.

    Sacramento, California

    State Universities Reeling After More Cuts

    California Governor Jerry Brown signed a budget last week that will inflict yet another round of steep cuts on the state's already cash-strapped university systems. The budget will reduce payments for the next academic year by $650 million each to the 10-school University of California (UC) system and to the 23 campuses that make up the California State University. The UC system has seen state funding drop from $15,020 per student in 2000–01 to $8220 in 2010–11, revenue that the institutions have tried to recoup by raising tuition substantially. Some administrators say the cuts have already hurt the university's ability to recruit and retain top researchers.

    California is not alone in its fiscal pain. This year neighboring Arizona cut its contributions to its three state universities by $170 million, or about 20%. Pennsylvania State University will take a 19% cut. In Michigan, state universities will see a 15% drop for the 2011–12 academic year. To make ends meet, university administrators across the country will have to choose from an unappetizing menu of layoffs, salary caps, enrollment limits, and tuition hikes.

    Darmstadt, Germany

    Scientists Reconnect With Cluster Mission


    The European Space Agency's Cluster mission is back in the fold after controllers fixed a serious glitch.

    Cluster is comprised of four identical satellites that have been studying Earth's space environment and the solar wind since 2000. They pirouette around each other as they orbit, enabling scientists to map space in 3D. Each craft carries 11 sensors, of which five make up the Wave Experiment Consortium. But in March the five on satellite 3 failed to respond to ground commands.

    Several weeks of intense work traced the problem to the simultaneous locking of all five power switches to the instruments—an eventuality that designers thought too unikely to consider. But Cluster's control team came up with a scheme to use a power cable and its backup cable simultaneously—normally forbidden in satellite operations. During a tense day last month, controllers sent up a series of commands that successfully flipped each of the power switches.

    “We were lucky to get it back on,” says deputy project scientists Arnaud Masson. Team members are working to ensure that something similar doesn't happen again.

    Zagreb, Croatia

    Medical Journal Editors Resign Amid Acrimony

    The two editors-in-chief of the Croatian Medical Journal (CMJ) resigned on 28 June, along with the majority of the journal's editorial board, in the latest episode of a decadelong, bitter fight between the journal's editors and its management board.

    Founded in 1991, CMJ has the highest-impact factor of any Croatian journal, and it has won international plaudits. But its editors have long battled the University of Zagreb's medical faculty, which, along with three other medical schools, owns the journal (Science, 18 April 2008, p. 304). The current editors-in-chief, Ana Marušić of the University of Split School of Medicine and Ivan Damjanov of the University of Kansas School of Medicine, say they threw in the towel because “obstruction” by the management board has made running the journal virtually impossible. A proposed change in the journal's management structure may have cost them their jobs anyway.

  2. Random Sample


    >The National Institutes of Health's high-profile initiative to diagnose mystery illnesses has stopped taking new applications, likely for just a few months. The program, started in 2008, has been overwhelmed by some 5400 inquiries and nearly 2000 full applications. It has investigated around 350 cases and has built up a backlog of about 100 enrolled patients.

    They Said It

    “It's like piranha. They sense blood in the water.”

    —Gene Lucas, University of California, Santa Barbara's executive vice chancellor, said of other universities recruiting UC scientists, in an interview with the Los Angeles Times.

    A Final Plan for the Spotted Owl


    The decline of the northern spotted owl in the 1980s led to dramatic restrictions on logging in Oregon and Washington. But the population has continued to shrink by about 3% a year, and there may be as few as 7000 owls left. On 30 June, the U.S. Fish and Wildlife Service (FWS) released a final version of a recovery plan for the owl. Topping the list is protection of forest habitat, preventing forest fires, and dealing with the barred owl, which has invaded the spotted owls' territory. Federal officials will have to consult the recovery plan whenever they consider major actions that might impact the owl, such as revising how they manage forests.

    Controversy is far from over, however: FWS is considering an experimental killing of barred owls to see if that will benefit the spotted owls. And, as a result of a lawsuit, FWS will reexamine the amount and location of critical habitat before 15 November.

    By the Numbers

    12,000–24,000 — Tons of plastic that deep-dwelling North Pacific fish ingest each year, based on findings from the Scripps Environmental Accumulation of Plastic Expedition, known as SEAPLEX.

    €80.2 billion — Initial proposal by the European Commission for research and innovation funding in 2014–20 under the Horizon 2020 program (formerly called Framework). That would be a 46% increase over current spending.

    50% — Loss in the amount of land suitable for cultivating premium wine grapes in high-value areas of northern California by 2040 because of global warming, according to a projection in Environmental Research Letters.

    Miniature Art Masters


    Microbiologist Rosa María Montes Estellés once infected a church mural with bacteria. But it was for a good cause: The bacteria ate their way through 4 centuries of grime encrusted on a mural at Santos Juanes Church in Valencia, Spain, exposing the underlying colors.

    Bacteria are only the latest tool in the art restorer's arsenal. Restorers use microabrasion, burly bristles, and chemical washes to strip layers of pollution from buildings, statues, and paintings. But each method has shortcomings: They can put the underlying artwork at risk or poison workers, and they often require slow and painstaking manual labor. So in 2005, a group of Italian art restorers tried a new tack: They bred bacteria to remove an obstinate layer of collagen from the murals of Campo Santo di Pisa.

    At Santos Juanes, the offending material was a crusty white mixture of salt, sulfates, nitrates, and carbon, originating from centuries of rainwater mixing with deposits from nesting birds and insects in the roof above the murals. Over time, the material slid downward, encrusting the paintings, where it fermented together with atmospheric pollutants. Montes and colleagues at the Polytechnic University of Valencia selected and “trained” a nitrogen-loving type of bacteria, Pseudomonas stutzeri, to eat the noxious blend.

    How to apply the bacteria was a challenge. After testing different materials, Montes and biologist Pilar Bosch chose a gel that keeps the bacteria wet and alive but doesn't sink into the underlying paint. The team's preliminary results will appear in a forthcoming issue of Arché. Meanwhile, Montes hopes to develop more and better treatments customized for different surfaces and pollutants.

  3. Newsmakers

    Scientist-Entrepreneur Offers Origin-of-Life Prize

    Harry Lonsdale, a millionaire scientist who is an avowed atheist, has announced a $50,000 prize to promote research on the origin of life. He hopes that researchers working on the question will eventually prove that life's origins can be fully explained by physical and chemical processes without invoking a creator.

    Lonsdale, a 79-year-old retired chemist in Bend, Oregon, made a fortune as the founder of a drug development and research company. He ran for the U.S. Senate as a Democratic nominee in the 1990s.


    His award would provide $50,000 for the best proposal to study the origin of life and up to $2 million in potential research funding. Applicants are invited to submit “a cogent hypothesis for how life first arose, including its plausible chemistry, and for how primitive life could have evolved to modern biological cells, including the present genetic material and metabolism.” A panel of prominent origin researchers—such as Harvard Medical School Nobelist Jack Szostak and NASA astrobiologist Chris McKay—will review proposals starting this month. An award, or multiple, will be announced early next year.

  4. Nuclear Waste

    Waste Panel Expected to Back Interim Storage

    1. Eli Kintisch

    A blue-ribbon commission signals that spent nuclear fuel should cool above ground while the United States figures out long-term disposal.

    Hot stuff.

    Spent fuel being lowered into a storage cask at a commercial nuclear reactor in Virginia.


    After killing the project to establish a nuclear waste repository at Yucca Mountain, Nevada, last year, President Barack Obama set up a commission to chart a new course for U.S. nuclear waste policy. The group, which is set to deliver its interim findings at the end of this month, is expected to say that the answers to America's nuclear waste conundrum are technically feasible. The problem, however, is that those solutions are likely to be, in political terms, radioactive.

    The Blue Ribbon Commission on America's Nuclear Future confronts a challenge that has stymied Washington for 40 years: the nation's relentless production of nuclear waste. In recent decades, U.S. reactors have created more than 2000 metric tons of highly radioactive spent fuel each year. Codified in law in 1987, the Yucca plan meant the spent fuel, held in bundles of 4-meter-long zirconium alloy tubes, would be cooled for up to a decade in storage pools at U.S. reactors. Then it would be shipped to Yucca Mountain, transferred into steel cylinders, and further cooled by fans for 50 years. When the facility contained 70,000 tons of waste, it would be closed up.

    In the past 24 years, the Department of Energy (DOE) has built an 8-kilometer-long tunnel at Yucca and has conducted experiments to ensure that the repository could hold the waste for up to 1 million years without releasing dangerous amounts of radiation. But although the government has spent roughly $10 billion on the project, lawsuits, red tape, and political opposition have prevented DOE from disposing of a single ton of commercial fuel. About 65,000 tons of spent nuclear fuel are piled up at U.S. reactors in cooling pools and in steel-and-concrete casks stored outdoors. Some experts believe the pools represent unacceptable safety or environmental risks in the case of natural calamity or terrorist attack. But moving cooled-down fuel from U.S. pools into casks, which are considered safer, would cost utilities billions of dollars.

    To alleviate this pressure on reactor sites and buy the government time to establish a permanent repository, the commission will likely call for an important new step: interim storage of the fuel in one or several central locations. After cooling in pools for a decade, fuel would be transferred to such a facility to be stored in outdoor steel-and-concrete casks for “multiple decades up to 100 years or possibly more.” Over that period, the commission envisions, expanded federal research into fuel recycling or other technologies might reduce the amount of fuel requiring disposal. Meanwhile, federal officials would have a second chance to establish a permanent U.S. geologic repository—this time, perhaps, in a fashion less acrimonious than the Yucca effort.

    Buying time

    “Consolidated interim storage preserves options while other aspects of an integrated waste management strategy can be developed,” says one of three commission subcommittee reports released in June. Later this month, an interim report from the full commission is expected; given the hundreds of hours of public testimony and published documents cited in the lengthy subcommittee reports, experts expect the final version, scheduled to be released in January 2012, to offer substantially the same conclusions.

    In addition to paving the political and logistical route to disposal, central, interim storage sites could make the repository easier to design and build. Building the Yucca repository required a number of engineering tradeoffs, explains physicist Charles Forsberg of the Massachusetts Institute of Technology (MIT) in Cambridge, and the site's “awkward” design was a stumbling block to getting it licensed.

    One reason was that Yucca Mountain had to cool waste before permanently storing it. Spent fuel straight from the reactor can quickly reach 1500°C, hot enough to destroy the tubes that hold it. Cooling for about a decade in storage pools dissipates most of the heat from the shortest-lived isotopes. But after being bundled together and entombed in the mountain for centuries, it might still gradually create enough heat to aid corrosion of the tubes, create dangerous steam within the tunnels, or even, over time, alter the geology of the site. First cooling the waste for at least 5 decades at interim storage sites could eliminate the need for fans at a permanent repository, says Forsberg, co-author of several influential MIT reports on nuclear waste. The interior of the long-term repository—compared with Yucca Mountain—would also require less ventilation and less access by remote devices to handle the fuel after emplacement, and it could be more easily sealed with an appropriate fill.


    In any case, experts agree, some new plan for waste storage is essential. Waste currently stored in pools and casks at U.S. sites does not pose “unmanageable … safety or security risks,” says a subcommittee report. But every ton that stays at reactor sites makes those risks slightly greater. Fuel in U.S. spent fuel pools is packed four times as densely as it was 25 years ago, raising concerns about the risk of explosions or meltdown if the pools were to empty in an accident. The tsunami that devastated the Fukushima nuclear plant in Japan in March may have resulted in a loss of water in one of its ponds (Science, 1 April, p. 24). A draft commission report says the issue of the safety of keeping fuel densely packed in pools should be “reexamined,” although “it is still too early to draw definitive conclusions” from the Fukushima accident. It calls for an expert panel at the National Academies to tackle the subject.

    Plain spent.

    Assuming no new plants, used fuel stores will more than double by 2050.


    If an interim storage site could get licensed—a big if, given political sensibilities—it might save money for utilities and the government, which is currently paying hundreds of millions of dollars in legal claims to utilities for the waste. Nine decommissioned reactor sites in the United States currently house nuclear fuel in aboveground casks. Centralized storage could save utilities billions in security costs and by freeing the land for other uses.

    As for long-term disposal, commissioners say the government should “expeditiously” move to set up a geologic repository—they were told not to specify where. “There is no ethical basis for abrogation of responsibility” for securing nuclear waste “to future generations,” a subcommittee report says. To avoid repeating the Yucca Mountain experience, which was plagued by opposition from the state of Nevada (see p. 150), the process of choosing a site should include “consultation, transparency, accountability, and scientific and technical credibility,” a draft report says. Commissioners are also likely to call for the project to be managed by a new, independent entity.

    The commission is also likely to recommend expanding research into technologies such as reprocessing, in which nuclear waste is converted back into nuclear fuel, and into advanced or more efficient reactors that might produce less waste. Nuclear power will never be completely clean, however. “No currently available or reasonably foreseeable reactor and fuel-cycle technologies … have the potential to fundamentally alter the waste management challenge,” the research subcommittee draft says.

    The road ahead

    Forecasting what the Blue Ribbon Commission will recommend is one thing; predicting what the Obama Administration and its successors will actually do with them is much harder. Several environmental and antinuclear groups have already spoken out against creating new storage sites for waste, and a commission subcommittee admits in a report that it's a “contentious issue.” Commissioners hope the track record of the 57 licensed fuel storage facilities—most at U.S. reactor sites—will alleviate some fears, and that an open site-selection process coupled with “incentives” like training and jobs for local communities and utilities will ultimately carry the day.

    But even simply getting money for more federal research into nuclear power could be a challenge. As the budget process in Washington grows ever more contentious, lobbyists and activists alike are increasingly skeptical that substantial increases can happen soon. “I don't think the budgets are going to expand beyond what they are now,” says physicist Thomas Cochran of the Natural Resources Defense Council in Washington, D.C.

  5. Radioactive Waste Disposal

    Light at the End of the Radwaste Disposal Tunnel Could Be Real

    1. Richard A. Kerr

    A long run of failures could finally drive the United States to follow other countries' lead and accept radioactive waste disposal as the sociotechnological problem that it is.

    Yucca Mountain.

    The now-abandoned repository site's rock is perhaps the planet's most thoroughly studied.


    The Obama Administration's shutdown of the quarter-century-long, $15 billion effort to dispose of 65,000 tons of U.S. spent nuclear reactor fuel in Nevada's Yucca Mountain could be the latest of many lessons learned around the world. Unforeseen technical problems have abounded there and at proposed disposal sites around the world, but no certain deal breakers have turned up.

    Yet, despite the absence of insurmountable geologic or engineering obstacles, no permanent repository for spent reactor fuel has been built anywhere. Every country looking for a place to dispose of its wastes has stumbled in its early tries to site repositories. Almost invariably, a government decides which site would be suitable, it announces its decision, an uproar ensues from the locals, the government defends its chosen site, but eventually it is forced to abandon its choice as untenable.

    In the wake of the 2010 abandonment of the Yucca Mountain program, the U.S. advisory Nuclear Waste Technical Review Board (NWTRB) puts the United States among those nations whose waste-disposal programs “either have lost public trust and confidence or seem never to have merited it at all,” as the board stated in an April report to Congress. (Yet, ironically, the United States is the only country in the world to open and operate a nuclear waste repository: a facility for storing waste from the nuclear weapons program that doesn't include spent fuel.)

    So as the Administration's Blue Ribbon Commission on America's Nuclear Future prepares to deliver its draft report (see p. 148), many authoritative groups have been driving home the lessons learned from Yucca Mountain and around the world. NWTRB put it most succinctly: “The interdependencies, both subtle and overt, between the technical, social, and political forces are inescapable.”

    Uniformly dismal failure

    In the 1950s, when countries first started pondering how to dispose of spent nuclear fuel from power plants and radioactive waste from nuclear weapons production, the solution seemed straight-forward enough. Nuclear waste contains isotopes of elements that will remain radioactive for thousands to many hundreds of thousands of years. Rock formations hundreds of meters beneath the surface have been there, little disturbed, for millions if not billions of years. So put the wastes in tunnels in the rock, seal the tunnels, and the problem would be solved. Layers of deeply buried salt were an early favorite; if there's salt still there after millions of years, water—which can corrode stored waste and carry it back into the environment—won't be a factor. But whatever medium was at hand—salt, granite, clay, or volcanic ash turned to stone called tuff—looked promising to the government's experts charged with finding a suitable site.

    Despite the promising geology, the top-down approach just didn't pan out. Whether it was salt in Germany or old bedrock in the United Kingdom, Canada, or Scandinavia, “almost all countries that have tried to site repositories have had one or more failures,” notes a June draft report, Spent Fuel From Nuclear Power Reactors, from the International Panel on Fissile Materials (IPFM), an independent group of nuclear experts.

    In the United States, 4 decades of government efforts were marked “by heavy handedness on the part of the federal government and political uprisings in a succession of states where it proposed to site repositories,” notes the IPFM report. An early setback came near Lyons, Kansas, where in 1970 the Atomic Energy Commission (AEC)—the forerunner of today's Department of Energy (DOE)—decided to entomb highly radioactive wastes from nuclear weapons production in an abandoned salt mine. In 1957, a U.S. National Academies report had recommended layered salt formations for such wastes because, over time, salt would flow to seal in the wastes.

    But the head of the Kansas Geological Survey urged more study of the integrity of the proposed Lyons repository. AEC agreed but continued its preparatory work anyway. Fearing a fait accompli, the IPFM report says, Kansans and their politicians rose to oppose the plan. Technical revelations then lit the fuse on a by-now-politically-unstable situation. It turned out that the site had long ago been peppered with oil and gas wells with no assurance they had all been securely plugged. And several years earlier, a mining company pumping water into the formation nearby to dissolve and extract salt had 640 cubic meters of water go missing, suggesting that the salt geology was more complex and less well understood than the academies had assumed. AEC abandoned the site in 1971.

    Yucca Mountain's cycle from decision to abandonment was far more protracted. Acting under the 1982 Nuclear Waste Policy Act, DOE had selected three candidate sites: salt in Texas, basalt in Washington state, and volcanic tuff at Nevada's Yucca Mountain.

    Technically, Yucca Mountain looked promising. The spent fuel would be well above the water table and therefore exposed to the vanishingly small amount of water seeping from the desert above. The decisive factor, however, was political. At the time, the Democratic Party controlled both houses of the U.S. Congress, and the powerful speaker of the House represented Texas while the House majority leader represented Washington state. Nevada's delegation, however, was split between Democrats and Republicans and was new to Congress. In 1987, Congress struck the Texas and Washington sites from the list, leaving Yucca Mountain the only candidate in the running. Nevadans still call the act the “screw Nevada bill.”


    If Yucca Mountain had proved to be the perfect repository site, it might not have been abandoned, but investigations soon started to tarnish its luster. That's normal for site evaluations; as geophysicist Wendell Weart told Science in 1999, “You never feel quite as comfortable about a site as the day you start to study it.”

    Yucca Mountain's unwelcome surprises included the possibility of earthquakes and volcanic eruptions (Science, 8 November 1996, p. 913) and fears, later allayed, that the repository itself might explode like a nuclear bomb (Science, 30 June 1995, p. 1836). But the overarching concern has been the discovery that water seeps down through the mountain many times faster than had been thought. So, in the mountain's oxygen-rich interior, water laden with salt dissolved from the rock would drip onto spent-fuel assemblies still hot from their lingering radioactivity. That's a great recipe for corrosion. The seeping brine would release radionuclides from the spent fuel and carry them on through the rock as far as the water is going.

    To make matters worse, the planning horizon for Yucca Mountain got extended by a factor of 100. An academies study committee requested by Congress concluded that the risk of human exposure to radioactivity should be estimated out to the time of maximum exposure, when containment has failed and wastes have spread. That upped the time scientists had to predict the behavior of the repository and its wastes from 10,000 years to 1 million years.

    In response to such surprises, DOE hunkered down. “DOE lacked transparency in developing its plans for the Yucca Mountain repository,” an April report, Commercial Nuclear Waste, from the U.S. Government Accountability Office (GAO) concluded. For example, instead of polling the broad community for ideas, DOE designed titanium drip shields on its own to protect the waste. DOE did not “establish independent scientific panels or any form of state oversight that might have given affected parties more confidence in the solutions,” the report says; nor did it “promote state involvement in key decisions and oversight.”

    Could more transparency and cooperation have saved the day? Mineralogist Rodney Ewing of the University of Michigan, Ann Arbor, a longtime critic of the Yucca Mountain program, thinks so. “I really think if there's a strong scientific basis combined with public empowerment, you can make progress,” he says.

    The Swedish way.

    The KBS design: copper-clad wastes (yellow) encased in clay (pink) beneath 500 meters of granite.


    A more successful path

    As an example of how to do things right, Ewing and other critics often cite another DOE radwaste repository, the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico (Science, 12 March 1999, p. 1626). “It wasn't an easy sell,” Ewing says. “There were substantial objections to WIPP. But there was a process of public and scientific engagement, so at the end you could say, this makes sense. It worked, but it took time”—30 years of time.

    WIPP did start with several advantages over Yucca Mountain. First, the people of Carlsbad wanted it. When community leaders heard about the abandonment of the Lyons site, they offered their own layered salt as a replacement. They had just lost a major employer, a potash mining company, and were looking for an economic boost. And they were already familiar with the risks of mining, not to mention those from nearby nuclear testing. Their interest would never waiver.

    Awaiting disposal.

    These casks contain the spent fuel from the production of 110 billion kilowatt-hours of electricity during 28 years by the Connecticut Yankee nuclear power plant.


    The state of New Mexico, having constituencies other than Carlsbad to consider and a long and sometimes strained history of state-federal relations, was not so receptive. Nongovernmental organizations (NGOs), including environmental groups, objected to the Carlsbad site as well. But unlike the way Yucca Mountain turned out, a flurry of lawsuits brought by the state and NGOs led to concessions from DOE and constructive interventions by Congress. A quasi-independent Environmental Evaluation Group with both state and federal funding provided credible scientific information to the state and the public when inevitable technical issues arose. And a signed agreement made the state “equal partners with DOE in the development of WIPP,” says Mark Gaffigan, lead author of the GAO report.

    Congressional legislation helped, too. It limited WIPP to defense-related waste such as rags, protective clothes, and tools contaminated with toxic, long-lived radio-nuclides including plutonium. The absence of high-level wastes such as thermally hot spent fuel eased relations between DOE and the state and simplified the repository design. Legislation also gave oversight of the repository to the U.S. Environmental Protection Agency, which was able to retain the 10,000-year standard for maintaining repository integrity without going to a million-year standard. And legislation provided New Mexico with $280 million in compensation over 14 years. WIPP received its first wastes in 1999; today, 9000 shipments of wastes totaling 71,000 cubic meters have been stored there.

    No one else has managed to open a repository for anything but low-level wastes, but two countries—Sweden and Finland—have gotten as far as selecting sites, although they have not yet given them final approval. As laid out in an IPFM report chapter by physicist Johan Swahn of the NGO Office for Nuclear Waste Review (MKG), Sweden started with some advantages. For one, Sweden began its site search with a relatively robust repository design in hand. Unlike the approach at Yucca Mountain, the Swedish KBS method developed by SKB, the nuclear waste company responsible for ultimate disposal, does not depend solely on geology for containment. Spent fuel would be encased in 5 centimeters of copper surrounded by extremely low-permeability clay.

    Sweden was also able to make changes in midstream. After provoking public outcries with uninvited exploratory drilling for a site, SKB backtracked and asked communities to volunteer as repository sites with the right to back out at any point. As in the case of WIPP, volunteers were looking for economic benefits. And they also were familiar with things nuclear; each of the two finalists already had a nuclear plant and one had a low-level waste site, the other a centralized facility for temporary spent-fuel storage. The Swedish government instituted a relatively open and consultative site-approval process, going so far as to fund NGOs such as MKG to monitor the process. And, in contrast to Yucca Mountain, that process sets a more practical standard to shoot for. It does not depend solely on quantitative calculations of the risk of repository failure out to a million years. Beyond a few hundreds of thousands of years, more qualitative arguments for repository safety can be made.

    A U.S. way ahead?

    After seeing these and other reports, hearing testimony, and making site visits, the Obama Administration's Blue Ribbon Commission looks set to recommend later this month a consent-based, transparent, and flexible approach to nuclear waste disposal. However, even strictly applying lessons learned from Sweden and WIPP won't guarantee smooth sailing. For one thing, the technical challenges of storing nuclear waste safely for many millennia have not gone away. In Sweden, for example, after 30 years of development, the KBS disposal system has developed what could be a major problem. Laboratory studies have lately raised the possibility that the copper cladding meant to shield the waste from groundwater may be much more prone to corrosion than anyone had suspected. The site-approval process, now under way, will consider just how significant a problem that is.

    On the social side, the United States is not Sweden, Swahn points out. “Your political system has more difficulties than we have dealing with these sorts of issues,” he says. “Trust is important in this country, and people trust the system. That is very, very different.”

  6. Japan Disaster

    Picking Up the Pieces at Ravaged Tohoku University

    1. Dennis Normile

    Four months after the earthquake and tsunami disaster, Tohoku researchers are finding new meaning in their work.

    Going, going …

    The 11 March tsunami swamped a Tohoku University marine science center (right), washing away equipment and leaving debris (left).


    SENDAI, JAPAN—The first tremors to arrive at the chemistry building on Tohoku University's Aobayama campus on 11 March were no stronger than others that routinely rattle this earthquake-prone region. But it was a matter of course for chemist Hiromi Tobita to follow the department's standard procedure: He left his eighth-floor office and called for those in the labs to join him in the hallway to wait out the quake. The department made safe zones of the hallways by strictly limiting storage there to reprints and light, nonvolatile supplies kept in lockers bolted to the walls. The wisdom of that policy became evident moments later as the main shocks from the magnitude-9 earthquake sent fume hoods and ventilators, glassware, and chemicals raining down on the lab benches, and tossed desks and chairs about as if they were toys. “If I had stayed in my office, I would have been seriously injured if not killed,” Tobita says, as would his colleagues in the labs. The shaking went on for longer than any earthquake Tobita had ever felt. “It was impossible to stand. I was holding onto a locker; many students lay down on the floor,” he says. When it subsided, everyone dashed for the stairs, hearing the hiss of escaping gas and sniffing toxic chemicals and smoke from a fire on the seventh floor. They wondered if they would ever return to the labs.

    Zeroed out.

    The marine population genetics group lost all of its equipment and most of its data and samples.


    With communications cut, no one knew what was happening off campus. But Tohoku geologist Koji Minoura had an inkling. After years of matching field evidence and historical records, he had published a claim in 2001 that in the year 869 C.E., during Japan's Jogan era, a once-in-1000-years earthquake triggered a stupendous tsunami that ran up to 3 kilometers inland along hundreds of kilometers of Japan's eastern coast. As he huddled under a table in his sixth-floor office to avoid the books and papers cascading from shelves, the ferocity of the shaking made him think: “This is it! This is the return of Jogan!”

    It would be several days before Minoura appreciated how awfully prescient his 2001 paper had been. Some Tohoku colleagues found out within minutes. As those at the Aobayama campus were fleeing buildings, a dozen students and staff members at a marine Field Science Center 54 kilometers east in Onagawa were “in a leisurely way thinking maybe we should evacuate,” says Manami Kanno, an assistant professor who works on marine population genetics. The center's two-story buildings rode out the earthquake with minimal damage. But town loudspeakers were warning of a “big tsunami.” “After an earthquake, they often issue tsunami warnings,” Kanno says. So the researchers coolly collected their belongings and drove to a designated spot deemed safe for 10-meter-high waves. They milled around, not knowing quite what to expect. Then it came. “It wasn't water. It was a mountain of houses, cars, and debris coming toward us,” Kanno says. They fled on foot for higher ground. One center technician had stayed behind and climbed a hill behind the center snapping pictures as the waters swamped the first floors, the second floors, and finally topped the roofs of the buildings. Then the tsunami receded as quickly as it had come, sweeping away their cars, research equipment, computers, and almost every bit of data and sample collected over the past 8 years.

    Tohoku University lost three students. But through good fortune, neither it nor any other major university or institute in Japan reported deaths or casualties among staff members.

    The devastation inflicted upon labs and experiments is a different story. The education ministry last May estimated that the 11 March earthquake and tsunami caused $664 million in damage to buildings and major facilities at 72 national universities and institutes. That figure does not include personal computers, bench-top microscopes, and other instruments, or research materials. Factoring such items in, Tohoku University, the region's higher education flagship, says that it alone suffered $990 million in damage.


    Hallway refuges prevented injuries to chemist Hiromi Tobita's group.


    Money for repairs and new equipment is flowing, thanks to an emergency budget announced in April. For some scientists, resuming research simply meant waiting for utilities to come back online and cleaning up. “A lot of groups are already back to work,” says materials scientist Akihisa Inoue, president of Tohoku University.

    But scores more face months of idleness. Some are waiting for major equipment to be restored (see sidebar). Others lost exceptional or irreplaceable samples and lab animals. For a few, the tsunami wiped out a lifetime of work. “We are starting from zero,” says Minoru Ikeda, a marine population geneticist at Onagawa field station. He lost all of the data and samples for a completed but unpublished study on genetic diversity of sweetfish, or Plecoglossus altivelis, in East Asia that he had spent 8 years collecting. “There is nothing else to do but to resume research activities as quickly as possible,” he says. As scientists, “we have to produce results.” For many other researchers, the disaster has sent them in new directions.

    Fear of heights

    In Tohoku's chemistry department, Tobita is among the unlucky few unable to really get back to work. Labs on the sixth floor and below are mostly back to normal. Groups requiring fume hoods had been located on the seventh and eighth floors to minimize duct-work needed to reach rooftop vents. Those floors are still off-limits because of extensive damage to walls, ceilings, and equipment, and the continuing danger from aftershocks. Plus, Tobita says, the thought of returning to work on the upper floors “terrifies everyone.”

    Tobita lost more than his lab. He works on inorganometallic compounds, such as silicon and germanium or silicon and ruthenium. These little-understood exotic combinations may eventually prove valuable as catalysts. But they are sensitive to air, moisture, and temperature and were stored in glove boxes. After the building lost electricity, 100 or more painstakingly created compounds decomposed.

    Tohoku plans to erect a prefabricated building to house the displaced chemistry groups, but it won't be ready until fall. In the meantime, Tobita's group is scattered in labs on two campuses. With no fume hoods and one glove box, they can only prepare precursor compounds to use when the new lab is ready. Tobita says his research plans have been set back at least 6 months. He is working on niche compounds, so he's not worried about being scooped. But he frets about the effect of the delay on his graduate students' thesis work, especially those hoping to get their degrees next March. The faculty is discussing how to factor the disaster into student evaluations.

    The effect on students is a major consideration for Tohoku developmental biologist Junken Aoki. He was at a seminar in Tokyo when the earthquake struck. He quickly confirmed that his family was safe. He worried about his team, until a colleague got through by phone and let him know everyone was okay. Then Aoki thought about the 4000 zebrafish his group uses to study bone and blood vessel formation. Temperatures in Sendai were hovering around 0°C, and with the power out, labs were growing cold. “Below 16°[C] the fish die,” he says.

    The next day, Aoki loaded his car with water, instant noodles, flashlights, and batteries and drove to Sendai, taking a circuitous route over back roads because the expressway was closed. The normally 5-hour trip took 12 hours. He stayed the night and then packed a couple of specimens from each of his 50 lines in special containers and returned to Tokyo, delivering the fish to the lab of a friend at Tokyo Medical and Dental University.

    Early last month, Aoki's group brought the zebrafish back to Sendai and resumed their research. Before the quake, he had also experimented on mice to probe the metabolic pathways and functions of lysophospholipids. These studies are on hold. The department had to destroy its 500 mice because the earthquake cracked walls, breaching the pathogen-free environment. It will take a year to breed a sufficient number of animals to restart research, Aoki says. That means a change of plan for three Ph.D. students who were using knockout mice for thesis research. One is switching to zebrafish. Another plans in vitro studies. The third will try blocking a target gene in wild-type mice. With offers of assistance pouring in, several group members moved temporarily to labs at other Japanese universities, sparking collaborative projects. “That was one of the good things that came out of this,” Aoki says.

    Hardest hit at Tohoku is the marine population genetics group. “Our equipment is all gone, almost all of our samples are gone, and almost all of our data is gone,” Ikeda says. In its place, the tsunami filled the center with fishing gear and other flotsam from elsewhere in town. And it left, like a pair of exclamation points, houses perched atop each of the center's two buildings.

    The center's small research vessel survived because two staffers, following standard procedure, put to sea when the shaking stopped. Standard procedures didn't extend to backing up data to remote servers before the tsunami carried away their computers. “We never thought of this risk,” Ikeda says. One grad student was away for the day and had his laptop—and thus his data—with him. Some tissue samples were recovered, and the researchers will try to extract DNA.

    Back to work.

    Geologist Koji Minoura (top) searches for ancient tsunamis, and biologist Junken Aoki (above) breeds zebrafish. Tohoku President Akihisa Inoue (below) is planning new programs.


    “Researchers are thinking of what they can contribute to the restoration.”



    The group is now working out of a lab at one of Tohoku's Sendai campuses, about 2 hours from Onagawa. They are just starting to accumulate basic lab equipment and arranging to borrow time on sequencers. They are still mulling over how to restart their research. One thing that will keep them busy is a proposal to study the impact of the tsunami on marine ecosystems and the recovery of fisheries.

    The university is still studying whether to rebuild the center in its present location, build anew on higher ground, or move to another city. Ph.D. student Azuma Kamiyama isn't waiting for a decision: She's going back to Onagawa. She had lived in Onagawa for 6 years and counts friends and acquaintances among the town's 872 dead and missing. Some 80% of the town's buildings were washed away; the tsunami left Kamiyama, who had been living in a seaside dormitory, with only the clothes on her back and her iPhone. She has taken leave from the university to work for the local government. “I want to help in the reconstruction of the town rather than work on research,” she says.

    Other scientists also say they were profoundly affected by the disaster. “My life and work have been completely changed,” Minoura says. He had never thought about how his findings could influence public policy, nor had he courted the media. If Minoura confirms his suspicions that a similarly massive tsunami occurred in 869 C.E., farther to the north on an adjacent segment of the fault that ruptured in March, he says he will speak up more forcefully about the risk, particularly to a cluster of nuclear facilities on the coast smack in the middle of the region. “I can't be silent,” he says.

    The 11 March disaster has many in the Tohoku University community thinking beyond the campus. Dozens of students and faculty members volunteered in evacuation centers. And now, Inoue says, “researchers are thinking of what they can contribute to the restoration.” One group wants to study how to strengthen phone systems such that they function through a disaster. Others have considered how to make coastal communities less vulnerable to tsunamis. There are proposals to investigate new approaches to energy conservation and alternative electricity generation. And economists and engineers have ideas for rebuilding the region's shattered economy.

    To implement this research agenda, Tohoku plans to open the International Research Institute of Disaster Science, which will bring together 300 engineers and scientists from various disciplines. As the region's only comprehensive university, Tohoku feels a responsibility “to take this experience and use our creativity to contribute to society,” Inoue says. He hopes the effort will promote disaster preparedness and postdisaster recovery not only in Tohoku but worldwide.

  7. Japan Disaster

    Facilities Plot Research Revival

    1. Dennis Normile

    Scientists across northeastern Japan are striving to get their research back on track in the wake of the 11 March earthquake and tsunami.


    TOKYO—Among major research institutions, Tohoku University in Sendai was dealt the fiercest blow by the 11 March earthquake and tsunami (see main text). But scientists across northeastern Japan are striving to get their research back on track.

    Buffeted by the tsunami while docked in Hachinohe, the deep-sea drilling vessel Chikyu lost one of six thrusters that position the ship during drilling. After temporary repairs, Chikyu is now undergoing sea trials before embarking on a commercial oil exploration cruise to run until the end of the year. Plans for resuming scientific drilling are uncertain.

    Liquefaction of silty soils took a heavy toll at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai. Ground subsidence buckled roads and damaged site piping. Meanwhile, ground water seeped into the linear accelerator tunnel. But J-PARC buildings sit on deep piles that protect them from soil liquefaction, and they withstood the shaking with minimal damage. The 2-year-old, $1.5 billion lab features a 50-gigaelectronvolt synchrotron supporting physics, materials science, and biomedical studies. Repairs will take until fall; experiments could resume by the end of the year.

    The Naka Fusion Institute will test superconductive coils for the ITER fusion reactor now under construction in Cadarache, France. Engineers have declared the test building unsafe, and repairs will take another 6 months. The status of the test equipment and the impact on ITER's construction are unclear. The institute is also home to the JT-60 experimental fusion reactor, now being upgraded. Mostly unscathed, the revamped reactor expects to see first plasma in 2016.

    Damage to buildings was light at the High Energy Accelerator Research Organization (KEK) in Tsukuba. But powerful magnets and detectors were shifted out of alignment or knocked to the floor. Scientists are now realigning beamlines and hope to restart experiments this fall.

    Up the road from KEK, the University of Tsukuba sustained about $87 million in damage to buildings and research equipment. Most research groups have returned to work after cleaning up and buying new instruments. But the earthquake may have delivered a knockout blow to Tsukuba's 12UD Pelletron tandem accelerator, used for nuclear physics and accelerator mass spectrometry. The facility is 35 years old, “and it would be very difficult to restore it,” says physicist Eiji Kita, who oversees the facility. He says it may be time to explore other research themes.

  8. Galaxy Evolution

    Milky Way Researchers' Home Away From Home

    1. Yudhijit Bhattacharjee

    Right next door and easy to study, Andromeda provides an excellent model of how our own galaxy probably evolved.


    If you were stuck forever inside your house, you could still learn a lot about houses by studying the one across the street. For astronomers trapped inside the Milky Way, the Andromeda galaxy is that neighboring house. And unlike the Milky Way, it can be imaged and studied in its entirety. At a distance of 2.5 million light-years, it is our closest galactic neighbor comparable to the Milky Way: far enough to offer a global view and close enough for telescopes to take a good look at individual stars inside it.

    As such, Andromeda has come to be regarded as one of the best models available for understanding the evolution of galaxies, including our own. That's why it has acquired a dedicated fan club of astronomers who have been studying the galaxy in ever-increasing detail over the past 15 years. These studies have helped astronomers define Andromeda's structure with unprecedented clarity, showing that the galaxy's disk and halo extend far beyond the boundaries that had been assumed before. The details of the picture are providing clues about how Andromeda came to be the galaxy it is today.

    Over the years, astronomers have discovered a dozen stellar streams falling into the outer regions of the galaxy that have been shown to be the remnants of smaller, satellite galaxies. The presence of these so-called tidal streams indicates that Andromeda has swallowed up numerous smaller galaxies in the past, incorporating their stars, gas, and other matter into its structure over billions of years. By studying the velocities and chemical compositions of stars within these streams and elsewhere in the galaxy, astronomers are beginning to piece together a detailed evolutionary history of Andromeda.

    Steady loss.

    A simulation showing how the Triangulum galaxy is beginning to lose stars and gas to Andromeda as it orbits the larger galaxy.


    The results confirm the long-held idea that large galaxies like our own have formed through the hierarchical assembly of smaller galaxies. The picture is what astronomers expected to see based on current theories of dark matter, the invisible stuff that makes up 80% of the universe. “The fact that Andromeda seems to be surrounded by all of these streams is a smoking gun that hierarchical structure formation is happening,” says James Bullock, a theoretical cosmologist at the University of California (UC), Irvine. “So indirectly, these numerous streams provide compelling evidence that we are not so far off base in our understanding of dark matter.”

    Mistaken identity

    Andromeda can be seen in the night sky with the naked eye. Like the Milky Way and other spiral galaxies, it consists of a flat, rotating disk of stars with a central bulge, nested inside a more-tenuous spherical halo of stars. Understanding the precise characteristics of its structure has gone hand in hand with efforts to understand its evolution.

    Until the early 2000s, astronomers thought Andromeda's halo was metal-rich: that is, made up of stars containing heavier elements in addition to hydrogen and helium. Because heavy elements formed relatively late in the universe's history, their presence is a marker of youth. Researchers studying the halo in 2002 estimated that a third of the stars were between 6 billion and 8 billion years old—nearly 4 billion years younger than most of their counterparts in the halo of the Milky Way. One possible explanation for the difference was that Andromeda began to form much later than the Milky Way did.

    But that age estimate turned out to be a case of mistaken identity: The stars that researchers had identified as belonging to Andromeda's halo were in fact from the outer reaches of the galaxy's bulge, where stars had been recently forming. Using the Keck telescopes atop Mauna Kea in Hawaii, a collaboration led by Puragra Guhathakurta of the University of California, Santa Cruz (UCSC), spotted faint stars far out from the bulge—up to five times farther out than where stars had been sighted before. In 2005, Guhathakurta's collaboration—which goes by the name SPLASH (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo)—reported that these newly discovered stars were part of Andromeda's true halo and were as ancient as stars in the halo of the Milky Way.

    Star man.

    Guhathakurta helped locate Andromeda's true halo.


    The finding meant that Andromeda and the Milky Way were likely to have evolved through similar processes: interactions with other, ancient galaxies. Because the newly discovered stars could not possibly have been born so far from the central star-forming regions in Andromeda's disk, astronomers concluded that they probably came from other galaxies that were sucked into Andromeda.

    Death plunge

    Astronomers had already glimpsed one clear incident of cannibalism by Andromeda. In 2001, peering through the Isaac Newton Telescope on the Canary Islands, Rodrigo Ibata of the Strasbourg Observatory in France and his colleagues discovered a dense line of stars poking through Andromeda's southern halo and pointed toward its disk. They realized that it was a giant stream of stars moving in unison. “It was plunging radially toward the center of the galaxy,” says Scott Chapman, an astronomer at the University of Cambridge in the U.K. and a co-author of a Nature paper reporting the discovery.

    In 1994, Ibata had discovered a similar stream flowing into the Milky Way, which researchers determined to be a flow of stars from the Sagittarius dwarf elliptical galaxy, a satellite galaxy being shredded by the Milky Way. In Andromeda's case, the Giant Southern Stream—as the structure came to be called—was speculatively linked to two of Andromeda's satellites, M32 and M110, although there was no firm evidence for the connection.

    The stream quickly became the subject of detailed studies aimed at nailing its progenitor and figuring out exactly how the cataclysmic shredding had proceeded over time. Mark Fardal, now a postdoc at the University of Massachusetts, Amherst, was at the forefront of these efforts. Using data on the velocities and chemical abundances of stars within the stream, which revealed bifurcations and narrower currents inside it, Fardal came up with simulations of the event. He concluded that the stream had not come from M32 or M110 after all. It was likely some other local satellite that had been completely cannibalized by Andromeda, leaving no trace outside Andromeda's halo.

    Fardal suspects that the vanished satellite may have begun its plunge into Andromeda 700 million years ago. By that time, Andromeda's gravitational pull had gradually stripped the satellite of dark matter and outer stars over hundreds of millions of years. “It's the same phenomenon as tides on Earth, only much more extreme,” Fardal says. “You get a stretching of the satellite that results in stars being unbound from it.” In Fardal's estimate, the satellite behind the Giant Southern Stream may have been as massive as 3 billion suns, less than 1% of the mass of the Milky Way. Its shredding not only brought new material into Andromeda but also likely sent shock waves rippling through the galaxy, which might have induced the formation of new stars in other regions and shaped the overall structure of the galaxy in unknown ways.

    After the discovery of the Giant Southern Stream, astronomers stepped up efforts to look for other streams within Andromeda. Looking through the 8-meter Subaru telescope in Hawaii, SPLASH collaborators Mikito Tanaka and Masashi Chiba of Tohoku University in Japan discovered two dense lines of stars in the northwest region of the galaxy. An analysis of the stars' spectra yielded their velocities, from which researchers at UCSC confirmed that the lines were indeed streams. The stars were moving coherently “as a group that ‘remembers’ the orbital speed of the progenitor dwarf galaxy to which the stars once belonged,” Guhathakurta says.


    Reddish streak of stars high in heavy elements shows remains of a dwarf galaxy on Andromeda's outskirts.


    Mergers everywhere

    More recently, several more tidal streams have been discovered by the Pan-Andromeda Archaeological Survey (PAndAS), a collaboration led by Alan McConnachie at the Herzberg Institute of Astrophysics in Victoria, Canada. Observing with the Canada-France-Hawaii Telescope, the researchers surveyed the entire outskirts of Andromeda, identifying 17 dwarf satellites that had not been known before.

    “We've gone from not really knowing that galaxy cannibalism occurs to having a few examples of the process to knowing that this is an extremely common process.”



    “Some of the satellites are in a stage of significant disruption; others don't appear to be getting disrupted at all,” McConnachie says. “We also see a bunch of streams that don't seem to have a satellite connected to them, which means the satellite has exerted completely consumed.”

    The survey also showed just how powerful an influence Andromeda has exerted on its neighborhood. Mc-Connachie says he and his colleagues were surprised to discover that Andromeda was starting to nibble stars away from the Triangulum galaxy, a neighbor that is half the size of the Milky Way and several times larger than any dwarf. The researchers expected Triangulum's significant size and heft to protect it from Andromeda's gravitational tug.

    But on the edge of Triangulum, they saw “a vast, extended, distorted distribution of stars, which is exactly what you would expect of stars pulled off of Triangulum,” McConnachie says. His group has done simulations showing that “about 3 billion years ago, the Triangulum galaxy passed relatively close to Andromeda, and Andromeda's gravity caused several of Triangulum's stars to unravel,” McConnachie says. At some point in the future, Triangulum could end up as a line streaking through Andromeda's halo into its center.

    The discovery of the various tidal streams has convinced astronomers that the chewing up of small galaxies by bigger ones—and more generally galaxy mergers—are a frequent occurrence in the universe. “We've gone from not really knowing that galaxy cannibalism occurs to having a few examples of the process to knowing that this is an extremely common process,” McConnachie says.

    Guhathakurta says the number of streams suggests Andromeda may have had “a more troubled past than the Milky Way.” Researchers are now digging deeper into the streams to get a better handle on questions such as the durations of encounters with different satellites, the orbits of the progenitor galaxies, and the structural and chemical characteristics of the satellites before they were swallowed.

    The study of Andromeda has provided theorists with a rich trove of data to test ideas of galaxy evolution, says Bullock. “We can actually predict fairly accurately how many little dwarf galaxies should have been accreted and destroyed,” he says. “The first of these predictions were in place before PAndAS and SPLASH made their discoveries, and things look pretty good in comparison.” He says continued investigations of Andromeda will be critical for gaining key insights about the universe at large. “For example, how small do the dark matter clumps have to be before they stop making galaxies?” he says. “Andromeda provides a perfect place to explore these questions.”

  9. Galaxy Evolution

    Galaxy Zoo Volunteers Share Pain and Glory of Research

    1. Daniel Clery

    A project to “crowdsource” galactic classifications has paid off in ways the astronomers who started it never expected.

    Space oddity.

    Greenish “voorwerp” spotted by a Dutch volunteer still intrigues scientists.


    The automated surveys that are becoming increasingly common in astronomy are producing an embarrassment of riches for researchers. Projects such as the Sloan Digital Sky Survey (SDSS) are generating so much data that, in some cases, astronomers don't know what to do with them all. SDSS has compiled a list of more than 1 million galaxies. To glean information about galaxy evolution, however, astronomers need to know what type of galaxy each one is: spiral, barred spiral, elliptical, or something else. At present, the only reliable way to classify galaxies is to look at each one. But the SDSS list is so long that all the world's astronomers working together couldn't muster enough eyeballs for the task.

    Enter the “wisdom of crowds.” An online effort called Galaxy Zoo, launched in 2007, set a standard for citizen-scientist participation projects. Zealous volunteers astonished the project's organizers by classifying the entire catalog years ahead of schedule. The results have brought real statistical rigor to a field used to samples too small to support firm conclusions.

    But that's not all. Buoyed by the curiosity and dedication of the volunteers, the Galaxy Zoo team went on to ask more-complicated classification questions that led to studies they hadn't thought possible. And in an online discussion forum on the Galaxy Zoo Web site, volunteers have pointed to anomalies that on closer inspection have turned out to be genuinely new astronomical objects. “I'm incredibly impressed by what they've managed to achieve,” says University of Oxford astronomer Roger Davies, president of the Royal Astronomical Society. “They've made it possible to do things with a huge survey.”

    Uncaging astronomy

    Galaxy Zoo was born out of necessity—and tedium. Several groups have attempted to develop image-analysis programs to classify galaxies automatically. But galaxies are hard for a computer program to get a handle on. In general, they are starry hazes, some with spiral arms, some without; some tightly wound and others looser; sporting central bars of various lengths, or no bar; some viewed face-on and others edge-on; not to mention the universe's many misshapen oddball galaxies and messy galactic mergers in progress. As a result, software classification isn't yet a reliable method.

    A quick and easy way to sort galaxies into spirals (flat disks with arms) and ellipticals (featureless blobs with bright cores) is to look at their spectra. Spirals tend to have active star-forming regions that emit a lot of blue light, whereas ellipticals are generally composed of older, cooler stars emitting in the red. Astronomers have spotted exceptions to the rule—red spirals and blue ellipticals—but they haven't been sure how large these subsets were. In 2006, Kevin Schawinski, then a postgrad student at Oxford, set out to answer that question by eyeballing some 50,000 SDSS galaxies to pick out all the ellipticals and find out what proportion of them were blue. Schawinski succeeded, but the work was almost unbearably tedious. His main conclusion, he says, was that “there had to be a better way to do this.”

    Chatting in a pub, Schawinski and fellow astronomer Chris Lintott came up with the concept of Galaxy Zoo: an online appeal to thousands of citizen-scientists for help with visual galaxy classifications. Projects such as SETI@home had already shown that members of the public were willing to hand over their spare computer time to scientists, and some had enlisted real citizen participation. Stardust@Home, for example, asked volunteers to spot tracks of interstellar dust in samples brought back by NASA's Stardust comet-chasing mission. Stardust@Home recruited 20,000 people. Schawinski and Lintott figured that if they could get a quarter of that number to do one classification per day, they could work through the whole SDSS galaxy list in 3 years with each galaxy inspected by five different people.

    The Galaxy Zoo Web site was launched on 11 July 2007. A simple interface gave volunteers a brief tutorial and then set them off, asking simply whether each galaxy image was spiral or elliptical and whether it spun clockwise or anticlockwise. Participants could classify as many or as few as they liked and could break off and come back whenever they wanted. A news story on a BBC Web site set the ball rolling; after just 3 hours, Schawinski recalls, traffic was so heavy that Galaxy Zoo's site, hosted by Johns Hopkins University, crashed. The university quickly cloned the site onto other servers and got it working again in a few hours.


    Statistics from Galaxy Zoo led one researcher to probe unusual red spiral galaxies.


    Twelve hours after launch, Galaxy Zoo was receiving 20,000 classifications per hour. Two days later, the figure was 60,000 per hour, and after 10 days the public had submitted 8 million classifications. “There were so many classifying for a while, it was a bit scary,” says Karen Masters of the University of Portsmouth in the United Kingdom. By the time the Galaxy Zoo team submitted its first paper 9 months later, more than 100,000 volunteers had classified the whole SDSS catalog, with each galaxy viewed 38 times on average.

    This ability to do multiple classifications of the same object is one of the key strengths of Galaxy Zoo data. Fuzzy images of distant galaxies are difficult to classify, and even galaxy experts often disagree. But with Galaxy Zoo, if many volunteers click on the same type for a galaxy, you can be pretty sure of the result; if there is a spread of different classifications, you know you have to treat the result with care. “With a large number of evaluations, you can get a level of uncertainty,” Davies says. “This is a unique thing that Galaxy Zoo is able to do.”

    Seeing red

    One early result of the first phase of Galaxy Zoo was testing the traditional link between galactic color and shape: blue spirals and red ellipticals. Galaxy Zoo found that 80% of galaxies follow this pattern, but sizable minorities show different correlations. “It's reinvigorated the idea that morphology is important,” Masters says. “There was a trend to look only at color, but color is not the only way to look at a galaxy.” Whereas color tells you about a galaxy's stars, its shape gives you dynamical information, she says.

    Astronomers currently think that galaxies form when dark matter clusters together under its own gravity and then pulls in gas, dust, stars, and smaller galaxies to form the flat, extended disk of a spiral galaxy. The dark matter stays in a spherical “halo” that surrounds the whole galaxy. In spiral galaxies, stars keep forming in the disk as neutral hydrogen gas rains down from the halo into the spiral arms. Elliptical galaxies, in contrast, result when two galaxies of comparable masses collide. If one or both are spirals, their spiral structure is destroyed, leaving stars in random orbits around the galactic center. The collision also slams together gas clouds, causing a burst of intense star formation that flares and burns out quickly, using up all the hydrogen gas. The end result is a structureless blob of a galaxy with no gas clouds and few young stars.

    Masters set out to study the red spiral galaxies identified in the first phase of Galaxy Zoo. First she weeded out all the galaxies that weren't viewed face-on. (Spiral galaxies viewed edge-on look redder than they really are, she explains, because the dust in their galactic plane tends to redden starlight passing through it.) “There were so many galaxies that you can be selective,” she says. Masters noticed that barred spirals, galaxies with a linear structure through the center that links into the spiral arms, were twice as common in red spirals as in blue ones. Data from the second phase of Galaxy Zoo (GZ2) confirmed the pattern. In general, bluish light shows that a galaxy is still producing many young stars; reddish light indicates that it is not. Masters wondered whether the bars might be halting star formation, perhaps by channeling hydrogen gas from the arms into the core. “Do bars kill galaxies?” she wondered.

    Pick one.

    Humans still outperform software in placing galaxies within Hubble's classification scheme.


    If gas were pouring into a galaxy's center, Masters reasoned, the supermassive black hole there would heat it and spew out material as a huge, hot beacon of energy: an active galactic nucleus (AGN). When she checked galaxies' spectra for signs of such beacons, however, Masters failed to find a strong correlation between AGNs and red barred spirals. Now she suspects that something external, such as small neighboring galaxies, is stripping neutral hydrogen from the galactic halo of the red spirals and so depriving their arms of fuel for star formation. “A bar is a side effect of the process,” she says.

    As for the blue ellipticals, “we've got a better picture,” Schawinski says. The blue ones that SDSS is seeing tend to be small, recently formed ones that are still undergoing vigorous star formation before moving to a calmer phase. “Ellipticals quench star formation rapidly,” Schawinski says. Astronomers can see the process more clearly because of the huge sample provided by SDSS and the clear classification from Galaxy Zoo. “This very good consensus, on a million objects, you can't get any other way,” he says.

    Little green galaxies

    The success of Galaxy Zoo goes beyond the big number of eyes involved, researchers say. Volunteers have played pivotal roles in some new discoveries.

    In the days after Galaxy Zoo was launched, the research team was inundated with queries, both technical and scientific, from volunteers. Un able to field all of the questions, the researchers set up an online forum so that the volunteers, or “zooites” as they soon called themselves, could interact, veterans helping newcomers. The researchers could add comments when necessary and contribute occasional blog posts. “Setting up the forum was very important. It acted as an escape valve for things that didn't fit,” says William Keel of the University of Alabama, Tuscaloosa.

    Artist's conception.

    The saga of the Galaxy Zoo has been dramatized in an online graphic novel.


    One zooite, Dutch schoolteacher Hanny Van Arkel, spotted several oddities. They didn't appear to be galaxies at all but were more like green stars. She started a thread on the forum called “Give peas a chance,” and other volunteers soon contributed similar objects they'd found. Before long they had collected more than 100 “green peas.”

    Carolin Cardamone, a colleague of Schawinski's at the Massachusetts Institute of Technology in Cambridge, started to investigate. “They looked like stars,” she says, but when she checked their spectra, “the colors were very unlike stars.” Instead, the objects seemed to be very compact galaxies undergoing extreme star formation and emitting light strongly at a wavelength characteristic of highly ionized oxygen, which appears green in SDSS images. Using the peas identified by the zooites as a model, Cardamone developed a program to find others in the SDSS catalog. Zooites helped her analyze the new sample, too. “It's like having research assistants around the world working 24 hours a day,” she says.

    When Cardamone and others published a paper on the green pea sample in 2009, 10 zooites were acknowledged for their contributions. There's still much debate about what these objects actually are, but Schawinski says they most resemble the protogalaxies thought to have existed very early in the history of the universe. “They're living fossils that we can study in detail because they're close by,” he says.

    Van Arkel is much better known for another unusual object she found in Galaxy Zoo: a glowing green blob now known as Hanny's Voorwerp (Dutch for “object”). The blob happened to be in the image of a galaxy, IC 2497, but astronomers had no idea whether it was connected with the galaxy or was much more distant. Unusually, it was glowing very brightly at one particular wavelength. Astronomers got so curious that numerous telescopes were trained on the voorwerp, including Kitt Peak in Arizona, the orbiting Swift, Suzaku, and Hubble telescopes, the Westerbork radio telescope array in the Netherlands, and the Merlin array in the United Kingdom. It was eventually found to be a gas cloud in the vicinity of IC 2497, possibly a tidal tail drawn out when another galaxy passed nearby. Its emissions suggest it is being illuminated by intense light from a highly energetic AGN called a quasar, but here is no quasar in sight.

    The voorwerp is still puzzling astronomers. One current theory is that the center of IC 2497 was a quasar that has now switched off. But because the voorwerp is tens of thousands of light-years away, it's still being illuminated by light from the quasar. So in the voorwerp we're seeing the afterglow of the quasar although the quasar itself is gone. There are also suggestions that a jet of gas streaming out of the center of IC 2497 is impacting on the voorwerp, causing areas of star formation.

    Hoping to learn more about the life cycles of quasars, Keel asked the zooites to find other clouds similarly illuminated by now-dormant quasars. They sifted through 18,000 objects. Keel inspected the best candidates using telescopes at Kitt Peak and the Lick Observatory and found 19 promising clouds more than 30,000 light-years from a potential quasar. Keel has won time on the Hubble telescope to examine seven of them in detail. Working on the voorwerp, he says, has been “the most rewarding little chunk of science I've done in the past decade.”

    The Galaxy Zoo team learned an important lesson from the project's first phase: Don't underestimate the abilities of the zooites. In GZ2 they took the 250,000 brightest galaxies from the SDSS catalog and scrutinized them for more-detailed information, such as the number of spiral arms, how tightly they are wound, and the length of the bars. The response was again astonishing: 60 million classifications in 14 months. The first results using GZ2 data are just starting to come out.

    Meanwhile, zooites are hard at work on the third phase of the project, known as Hubble Zoo. It asks almost the same questions as GZ2 but applies them to a much deeper data set: Hubble Space Telescope images of more than 2 million galaxies covering 75% of the age of the universe. With this temporally deep sample, astronomers “can compare with the local universe to quantify things to do with galaxy evolution that they couldn't do before,” Keel says.

    In the future, zooites may grapple with data from even-more-powerful survey telescopes now being planned, such as the Square Kilometre Array and the Large Synoptic Survey Telescope (LSST). By the time LSST starts work later this decade, Keel says, astronomers expect that computers will be able to do much of the heavy lifting of classification. Human classifiers will be used to improve the software and look at anything odd the computer has trouble with. “I can see a tighter synergy between observers and software,” Keel says.

    Even as the use of software expands, however, Davies says it's “likely that [Galaxy Zoo–like] techniques will be widely used in the future.” That will be a relief to thousands of galaxy spotters around the globe. “The community of Galaxy Zoo gives them the opportunity to participate that they're looking for.”

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