Wednesday, March 11, 2009

Kepler takes to the heavens to look for other Earths

By Matt Ford

Kepler takes to the heavens to look for other Earths

Just seconds before 10:50pm Friday night on the east coast, a Delta II rocket carried NASA's tenth item in its "discovery" series, the Kepler Mission, into the night sky. The Kepler Mission has a singular focus: to search for other Earths. In pursuit of this goal, it is going to spend at least three and a half years, and possibly up to six, searching a single patch of the heavens for other planets that exist in the habitable zone of stars in the Milky Way.

In 1960, at the Green Bank meeting in Green Bank, West Virginia, a group of astronomers, physicists, biologists, and other scientists gather and established SETI as a scientific endeavor. At this meeting, Prof. Frank Drake put forth what is now termed the "Drake equation":

drakeEqn.pngIt attempts to ascertain the average number of civilizations that we may have the ability to contact in the Milky Way at any given time. In the equation, R* is the rate of star formation, fp is the fraction that contain planets, ne is the number of habitable planets, fl is the fraction that develops life, fi is the fraction that develops intelligent life, fc is the number of civilizations scientifically advanced enough to contact us, and L is the length of time that civilization lasts. Using Drake's 1960 values, he calculated that there would be 10 civilizations, on average, that we may be capable of communicating with.

The equation draws a great deal of criticism from those who claim the values for some of the terms are at best arbitrary and unknowable. Over the past 49 years, we have gotten a much better idea as to the rate of star formation in the Milky Way (R*), and in the past decade we are starting to get a handle on the number of exosolar planets that exist (fp). The Kepler Mission hopes to indirectly answer what fraction of stars have rocky, earth-sized planets that exist in the habitable zone about a star (ne)—the region of space near a star where liquid water exist as a stable phase.

So far, 342 exosolar planets have been detected by a variety of indirect—and a few direct—measurements. The vast majority of the exosolar planets found have been gas giants orbiting close to their stars. Known as hot Jupiters, these are planets that have a low probability of supporting life. The Kepler Mission will use a single piece of observational equipment—a highly advanced photometer—to look for Earth-like exosolar planets transiting their host star.


A transit is the name given to a planet passing in between us and its host star; such an event would be observed as a slight change in the output of the star. For an Earth-sized planet transiting a Sun-sized star, the change in the star's output would be less than 84 parts per million, and there would be less than a one percent chance of the transit even being viewable from Earth. Kepler's photometer is so sensitive that it will be capable of detecting a 20 parts-per-million change in stellar output in a star that is 250 times fainter than any that can be seen with the naked eye.

To rule out false positives, an object will need to make at least three transits with a consistent period and change in brightness. In order to maximize the chances of seeing such a rare event, the Kepler Mission will only look at a single area of the sky. For the next three and a half years, Kepler will look towards the constellations Cygnus and Lyra and stare at the over 100,000 stars in that region. The spacecraft's orbit will not be about the Earth itself, rather it will be placed into an Earth-trailing heliocentric orbit, which will allow for a very stable pointing attitude.

While in this orbit, different classes of planets will be discovered within different time frames. The first to be spotted will be the hot Jupiters, gas giants orbiting close to their host stars within a period of only a few days. Once about a year's worth of data is collected, Mercury-like planets—those with an orbit of a few months—will be able to be picked out. For planets like Earth, which require a full year to orbit a star, it will take the full three years of mission time to be able to conclusively identify these objects. As one mission scientist quipped, they are not looking for ET, but they may find ET's home.

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Cannibalistic Jupiter ate its early moons

by Marcus Chown

Jupiter now has only four large moons, but in the early days of the solar system it may have had 20 or more (Image: JPL / NASA)

THE four giant "Galilean" moons orbiting Jupiter are the last survivors of at least five generations of moons that once circled the gas giant.

"All the other moons - and there could have been 20 or more - were devoured by the planet in the early days of the solar system," says Robin Canup of the Southwest Research Institute in Boulder, Colorado.

The four Galilean moons have played a key role in the history of science - their discovery by Galileo 400 years ago provided irrefutable evidence that not all bodies orbited the Earth. But until recently, nobody had suspected that Jupiter had once had many more moons.

Astronomers have long been aware of a mystery thrown up by simulations of the way Jupiter and its moons formed, says Canup. These models indicate that the mass of the debris disc around Jupiter, from which the moons formed, was several tens of a per cent of the mass of giant planet. And yet only 2 per cent is enough to make the moons we see today.

Now Canup and her colleague William Ward believe they know why. The extra mass can be explained if other moons formed while the debris disc was still present ( "A key process is therefore the interaction between the growing moons and the disc material still flowing in from the solar system," says Canup. This interaction would have caused the early moons to spiral in towards Jupiter and eventually be "eaten".

This would explain the discrepancy in the earlier simulations, says Canup: as one set of moons was swallowed, a new set immediately began to form. "There could have been five generations of moons," she says. "The current Galilean moons formed just as the inflow of material into the disc from the solar system choked off, so they escaped the fate of their unfortunate predecessors."

According to Canup and Ward, in each generation the total mass of the moons was the same, but the number of moons could have varied. "We think something similar happened around Saturn, where the last generation contained one giant moon - Titan," says Canup.

This could have implications for the solar system as a whole. Rocky planets may take as long as 10 million years to aggregate, chunk by chunk. The process continues long after the debris disc around the sun has blown away, so these planets would not have been at risk of spiralling inwards.

In contrast, the gaseous cores of gas giants like Saturn and Jupiter condense out of the solar debris disc very quickly via gas shrinkage. This means they would have had time to interact with the debris disc. John Papaloizou of the University of Cambridge says it is entirely conceivable that the sun may have swallowed numerous gas cores before the current stable configuration of the solar system emerged.

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U.N. report: Forestry can create 10 million jobs

By Katy Byron

(CNN) -- The United Nations is urging countries to invest in green jobs working with "sustainable forest management" to address the growing problem of unemployment worldwide.

A deforested area appears in a rain forest in Brazil's Para state  in October.

A deforested area appears in a rain forest in Brazil's Para state in October.

At least 10 million such jobs could be created, the U.N. Food and Agriculture Organization will say in a report to be released this week.

The report does not mention any countries but is aimed at "mainly regions with substantial rural unemployment and degraded land areas," said C.T.S. Nair, chief economist in the U.N. Forestry Department and one of the authors of the report.

While all countries could benefit from investing in these green jobs, Nair said, Asia and Africa -- and to some extent Latin America -- could benefit the most. India, China and almost all countries in Africa stand to benefit, he added.

The United Nations said it already is seeing indications that some countries -- such as the United States, India and South Korea -- are interested and taking action to invest in sustainable forest management by making it part of their economic stimulus plans.

Sustainable forestry aims to prevent depletion of forests by managing them and making sure their use does not interfere with natural benefits or the local environment.

For example, in forests where wood is being removed, the United Nations is suggesting that people be hired to monitor and manage how much wood is taken out to ensure the forest does not become depleted and can grow back fully. Managers also would make sure the wood harvest wouldn't affect biodiversity and the water supply.

The report will be discussed and analyzed next week at the U.N. Committee on Forestry meeting in Rome, Italy. The Food and Agriculture Organization has designated next week as World Forest Week.

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Blue Ducks likely to die out in UK after male birds get together

By Caroline Gammell

Blue Ducks likely to die out in UK after male birds get together
Blue ducks Ben and Jerry at the Arundel Wetland Centre in West Sussex Photo: SOLENT

Keepers at a bird sanctuary in West Sussex hoped that the last remaining female Blue Duck in the country - called Cherry - might mate with either of the drakes, Ben or Jerry.

But neither male duck appeared interested and are now inseparable at the Arundel Wetland Centre, leaving Cherry to her own devices.

Centre warden Paul Stevens said he was disappointed that efforts to produce new Blue Duck offspring had failed but said the two male birds made "a lovely couple".

"They stay together all the time, parading up and down their enclosure and whistling to each other as a male might do with a female he wants to mate with," he said.

"People who visit the centre think they're a fantastic couple, without really coming around to the idea that they are two males.

"They both have very big personalities and people come from all over the country to come and see them.

Cherry doesn't seem bothered by it, she's just happy to keep herself to herself."

Blue ducks originate from New Zealand but there were thought to be just three birds in the UK.

Keepers initially introduced Ben to Cherry, but neither seemed keen. They then brought Jerry down from a sanctuary in London.

Mr Stevens said: "Cherry showed some interest in him. She displayed typical mating behaviour - she approached him and called to him, she even looked like she was nesting.

"We thought it was great and it was all going to happen but nothing ever did."

Mr Stevens said the male ducks were then placed in the same enclosure: "To our surprise the two males really took to each other and it was obvious that they really liked each other.

"It would have been nice to get a last clutch of eggs from Cherry but Ben and Jerry do make a lovely couple."

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Jeremy Clarkson and Michael O'Leary won't listen to green cliches and complaints about polar bears

George Marshall

Polar bears

Academics meeting in Bristol at the weekend for Britain's first conference on the psychology of climate change argued that the greatest obstacles to action are not technical, economic or political — they are the denial strategies that we adopt to protect ourselves from unwelcome information.

It is true that nearly 80% of people claim to be concerned about climate change. However, delve deeper and one finds that people have a remarkable tendency to define this concern in ways that keep it as far away as possible. They describe climate change as a global problem (but not a local one) as a future problem (not one for their own lifetimes) and absolve themselves of responsibility for either causing the problem or solving it.

Most disturbing of all, 60% of people believe that "many scientific experts still question if humans are contributing to climate change". Thirty per cent of people believe climate change is "largely down to natural causes", while 7% refuse to accept the climate is changing at all.

How is it possible that so many people are still unpersuaded by 40 years of research and the consensus of every major scientific institution in the world? Surely we are now long past the point at which the evidence became overwhelming?

If only belief formation were this simple. Having neither the time nor skills to weigh up each piece of evidence we fall back on decision-making shortcuts formed by our education, politics and class. In particular we measure new information against our life experience and the views of the people around us.

George Lakoff, of the University of California, argues that we often use metaphors to carry over experience from simple or concrete experiences into new domains. Thus, as politicians know very well, broad concepts such as freedom, independence, leadership, growth and pride can resonate far deeper than the policies they describe.

None of this bodes well for a rational approach to climate change. Climate change is invariably presented as an overwhelming threat requiring unprecedented restraint, sacrifice, and government intervention. The metaphors it invokes are poisonous to people who feel rewarded by free market capitalism and distrust government interference. It is hardly surprising that political world view is by far the greatest determinant of attitudes to climate change, especially in the US where three times more Republicans than Democrats believe that "too much fuss is made about global warming".

An intuitive suspicion is then reinforced by a deep distrust of the key messengers: the liberal media, politicians and green campaign groups. As Jeremy Clarkson says, bundling them all together: "...everything we've been told for the past five years by the government, Al Gore, Channel 4 News and hippies everywhere is a big bucket of nonsense." Michael O'Leary, the founder of Ryanair, likens "hairy dungaree and sandal wearing climate change alarmists" to "the CND nutters of the 1970s". These cultural prejudices, however simplistic, align belief with cultural allegiance: "People like us," they say, "do not believe in this tripe."

However much one distrusts environmentalists, it is harder to discount the scientists… depending, of course, on which scientists one listens to. The conservative news media, continues to provide a platform for the handful of scientists who reject the scientific consensus. Of the 18 experts that appeared in Channel 4's notorious sceptic documentary The Great Global Warming Swindle, 11 have been quoted in the past two years in the Daily and Sunday Telegraph, five of them more than five times.

Dr Myanna Lahsen, a cultural anthropologist at the University of Colorado, has specialised in understanding how professional scientists, some of them with highly respected careers, turn climate sceptic. She found the largest common factor was a shared sense that they had personally lost prestige and authority as the result of campaigns by liberals and environmentalists. She concluded that their engagement in climate issues "can be understood in part as a struggle to preserve their particular culturally charged understanding of environmental reality."

In other words, like the general public, they form their beliefs through reference to a world view formed through politics and life experience. In order to maintain their scepticism in the face of a sustained, and sometimes heated, challenge from their peers, they have created a mutually supportive dissident culture around an identity as victimised speakers for the truth.

This individualistic romantic image is nurtured by the libertarian right think tanks that promote the sceptic arguments. One academic study of 192 sceptic books and reports found that 92% were directly associated with right wing free market think tanks. It concluded that the denial of climate change had been deliberately constructed "as a tactic of an elite-driven counter-movement designed to combat environmentalism".

So, given that scepticism is rooted in a sustained and well-funded ideological movement, how can sceptics be swayed? One way is to reframe climate change in a way that rejects the green cliches and creates new metaphors with a wider resonance. So out with the polar bears and saving the planet. Instead let's talk of energy independence, and the potential for new enterprise.

And then there is peer pressure, probably the most important influence of all. So, when dealing with a sceptic, don't get into a head to head with them. Just politely point out all the people they know and respect who believe that climate change is a serious problem — and they aren't sandle-wearing tree huggers, are they?

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Gray Wolf Will Lose Protection in Part of U.S.


HELENA, Mont. — In a blow to environmental groups and a boost for ranchers, the Obama administration announced Friday that it would take the gray wolf off the endangered species list in Montana and Idaho, though it left the predator under federal protection in Wyoming.

Agence France-Presse — Getty Images

The gray wolf will remain on the federal endangered species list in Wyoming.

The delisting allows Montana and Idaho to assume complete management of the animal, which will include a hunting season in both states. The move also delists wolves in the western Great Lakes and parts of Oregon, Utah and Washington.

The new policy was announced by the Bush administration in January, but its adoption was delayed so the incoming Obama administration could assess it.

“The recovery of the gray wolf throughout significant portions of its historic range is one of the great success stories of the Endangered Species Act,” Interior Secretary Ken Salazar said. “Today, we have more than 5,500 wolves, including more than 1,600 in the Rockies.”

Jenny Harbine, a lawyer with Earthjustice in Bozeman, Mont., which has sued to keep the federal protections, said, “We’re disappointed.” She added, “Idaho has shown an eagerness to kill as many wolves as possible, and they are drawing up plans for killing wolves as we speak.”

In 2007, Gov. C. L. Otter of Idaho said he favored reducing the number of wolves there to 100 from more than 800. He also said he would be the first to buy a wolf hunting license.

Officially, however, Idaho has agreed in its state plan to maintain a population of 500 wolves. Montana has agreed to keep 400 wolves. If the number of animals falls below 150 total and 15 breeding pairs for three years in a row, the wolf will be relisted in that state.

Environmentalists sued last year to stop the delisting under the Bush administration. They argued that without protection, wolf numbers were not great enough to assure connectivity between animals in different regions of the northern Rockies, which is crucial to assuring long-term survival.

A federal judge agreed, issuing a temporary injunction to stop the delisting. The Fish and Wildlife Service then dropped its proposal for more study. “We now have information that wolves routinely move back and forth between recovery areas,” said Ed Bangs, the agency’s recovery coordinator in Helena, Mont. “We’ve resolved that issue.”

Environmentalists say they will take the issue back to court.

While state wolf management plans in Idaho and Montana assure protection, federal officials say, the one in Wyoming falls short, so the wolf will remain listed there. Yet in most of Wyoming, the wolf is designated as a predator and could be shot on sight if it were to be delisted. Controversy erupted last year when people chased wolves down on snowmobiles and killed them from planes.

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