Meeting climate targets may require reducing meat, dairy consumption

Greenhouse gas emissions from food production may threaten the UN climate target of limiting global warming to 2 degrees Celsius, according to research at Chalmers University of Technology, Sweden.On Monday 31 March the Intergovernmental Panel on Climate Change (IPCC) presents their report on the impacts of climate change.Carbon dioxide emissions from the energy and transportation sectors currently account for the largest share of climate pollution. However, a study from Chalmers now shows that eliminating these emissions would not guarantee staying below the UN limit. Emissions from agriculture threaten to keep increasing as global meat and dairy consumption increases. If agricultural emissions are not addressed, nitrous oxide from fields and methane from livestock may double by 2070. This alone would make meeting the climate target essentially impossible.”We have shown that reducing meat and dairy consumption is key to bringing agricultural climate pollution down to safe levels,” says Fredrik Hedenus, one of the study authors. “Broad dietary change can take a long time. We should already be thinking about how we can make our food more climate friendly.”By 2070, there will be many more of us on this planet. Diets high in meat, milk, cheese, and other food associated with high emissions are expected to become more common. Because agricultural emissions are difficult and expensive to reduce via changes in production methods or technology, these growing numbers of people, eating more meat and dairy, entail increasing amounts of climate pollution from the food sector.”These emissions can be reduced with efficiency gains in meat and dairy production, as well as with the aid of new technology,” says co-author Stefan Wirsenius. “But the potential reductions from these measures are fairly limited and will probably not suffice to keep us within the climate limit, if meat and dairy consumption continue to grow.”Beef and lamb account for the largest agricultural emissions, relative to the energy they provide. …

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Ancient sea creatures filtered food like modern whales

Ancient, giant marine animals used bizarre facial appendages to filter food from the ocean, according to new fossils discovered in northern Greenland. The new study, led by the University of Bristol and published today in Nature, describes how the strange species, called Tamisiocaris, used these huge, specialized appendages to filter plankton, similar to the way modern blue whales feed today.The animals lived 520 million years ago during the Early Cambrian, a period known as the ‘Cambrian Explosion’ in which all the major animal groups and complex ecosystems suddenly appeared. Tamisiocaris belongs to a group of animals called anomalocarids, a type of early arthropod that included the largest and some of the most iconic animals of the Cambrian period. They swam using flaps down either side of the body and had large appendages in front of their mouths that they most likely used to capture larger prey, such as trilobites.However, the newly discovered fossils show that those predators also evolved into suspension feeders, their grasping appendages morphing into a filtering apparatus that could be swept like a net through the water, trapping small crustaceans and other organisms as small as half a millimetre in size.The evolutionary trend that led from large, apex predators to gentle, suspension-feeding giants during the highly productive Cambrian period is one that has also taken place several other times throughout Earth’s history, according to lead author Dr Jakob Vinther, a lecturer in macroevolution at the University of Bristol.Dr Vinther said: “These primitive arthropods were, ecologically speaking, the sharks and whales of the Cambrian era. In both sharks and whales, some species evolved into suspension feeders and became gigantic, slow-moving animals that in turn fed on the smallest animals in the water.”In order to fully understand how the Tamisiocaris might have fed, the researchers created a 3D computer animation of the feeding appendage to explore the range of movements it could have made.”Tamisiocaris would have been a sweep net feeder, collecting particles in the fine mesh formed when it curled its appendage up against its mouth,” said Dr Martin Stein of the University of Copenhagen, who created the computer animation. “This is a rare instance when you can actually say something concrete about the feeding ecology of these types of ancient creatures with some confidence.”The discovery also helps highlight just how productive the Cambrian period was, showing how vastly different species of anomalocaridids evolved at that time, and provides further insight into the ecosystems that existed hundreds of millions of years ago.”The fact that large, free-swimming suspension feeders roamed the oceans tells us a lot about the ecosystem,” Dr Vinther said. “Feeding on the smallest particles by filtering them out of the water while actively swimming around requires a lot of energy — and therefore lots of food.”Tamisiocaris is one of many recent discoveries of remarkably diverse anomalocarids found in rocks aged 520 to 480 million years old. “We once thought that anomalocarids were a weird, failed experiment,” said co-author Dr Nicholas Longrich at the University of Bath. “Now we’re finding that they pulled off a major evolutionary explosion, doing everything from acting as top predators to feeding on tiny plankton.”The Tamisiocaris fossils were discovered during a series of recent expeditions led by co-author David Harper, a professor at Durham University. “The expeditions have unearthed a real treasure trove of new fossils in one of the remotest parts of the planet, and there are many new fossil animals still waiting to be described,” he said. …

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Plankton make scents for seabirds and a cooler planet

The top predators of the Southern Ocean, far-ranging seabirds, are tied both to the health of the ocean ecosystem and to global climate regulation through a mutual relationship with phytoplankton, according to newly published work from the University of California, Davis.When phytoplankton are eaten by grazing crustaceans called krill, they release a chemical signal that calls in krill-eating birds. At the same time, this chemical signal — dimethyl sulfide, or DMS — forms sulfur compounds in the atmosphere that promote cloud formation and help cool the planet. Seabirds consume the grazers, and fertilize the phytoplankton with iron, which is scarce in the vast Southern Ocean. The work was published March 3 in the Proceedings of the National Academy of Sciences.”The data are really striking,” said Gabrielle Nevitt, professor of neurobiology, physiology and behavior at UC Davis and co-author on the paper with graduate student Matthew Savoca. This suggests that marine top predators are important in climate regulation, although they are mostly left out of climate models, Nevitt said.”In addition to studying how these marine top predators are responding to climate change, our data suggest that more attention should be focused on how ecological systems, themselves, impact climate. Studying DMS as a signal molecule makes the connection,” she said.Nevitt has studied the sense of smell in ocean-going birds for about 25 years, and was the first to demonstrate that marine top predators use climate-regulating chemicals for foraging and navigation over the featureless ocean. DMS is now known to be an important signal for petrels and albatrosses, and the idea has been extended to various species of penguins, seals, sharks, sea turtles, coral reef fishes and possibly baleen whales, she said.Phytoplankton are the plants of the open ocean, absorbing carbon dioxide and sunlight to grow. When these plankton die, they release an enzyme that generates DMS.A role for DMS in regulating climate was proposed by Robert Charlson, James Lovelock, Meinrat Andreae and Stephen Warren in the 1980s. According to the CLAW hypothesis, warming oceans lead to more growth of green phytoplankton, which in turn release a precursor to DMS when they die. Rising levels of DMS in the atmosphere cause cloud formation, and clouds reflect sunlight, helping to cool the planet. …

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Volcanoes helped species survive ice ages

An international team of researchers has found evidence that the steam and heat from volcanoes and heated rocks allowed many species of plants and animals to survive past ice ages, helping scientists understand how species respond to climate change.The research could solve a long-running mystery about how some species survived and continued to evolve through past ice ages in parts of the planet covered by glaciers.The team, led by Dr Ceridwen Fraser from the Australian National University and Dr Aleks Terauds from the Australian Antarctic Division, studied tens of thousands of records of Antarctic species, collected over decades by hundreds of researchers, and found there are more species close to volcanoes, and fewer further away.”Volcanic steam can melt large ice caves under the glaciers, and it can be tens of degrees warmer in there than outside. Caves and warm steam fields would have been great places for species to hang out during ice ages,” Dr Fraser said.”We can learn a lot from looking at the impacts of past climate change as we try to deal with the accelerated change that humans are now causing.”While the study was based on Antarctica, the findings help scientists understand how species survived past ice ages in other icy regions, including in periods when it is thought there was little or no ice-free land on the planet.Antarctica has at least 16 volcanoes which have been active since the last ice age 20,000 years ago.The study examined diversity patterns of mosses, lichens and bugs which are still common in Antarctica today.Professor Peter Convey from the British Antarctic Survey said around 60 per cent of Antarctic invertebrate species are found nowhere else in the world.”They have clearly not arrived on the continent recently, but must have been there for millions of years. How they survived past ice ages — the most recent of which ended less than 20,000 years ago — has long puzzled scientists,” Professor Convey said.Dr Terauds of the Australian Antarctic Division ran the analyses, and says the patterns are striking.”The closer you get to volcanoes, the more species you find. This pattern supports our hypothesis that species have been expanding their ranges and gradually moving out from volcanic areas since the last ice age,” Dr Terauds said.Professor Steven Chown, from Monash University, says the research findings could help guide conservation efforts in Antarctica.”Knowing where the ‘hotspots’ of diversity are will help us to protect them as human-induced environmental changes continue to affect Antarctica,” Professor Chown said.Story Source:The above story is based on materials provided by Australian National University. Note: Materials may be edited for content and length.

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In grasslands remade by humans, animals may protect biodiversity: Grazers let in the light, rescue imperiled plants

A comparative study of grasslands on six continents suggests there may be a way to counteract the human-made overdose of fertilizer that threatens to permanently alter the biodiversity of the world’s native prairies.The solution is one that nature devised: let grazing animals crop the excess growth of fast growing grasses that can out-compete native plants in an over-fertilized world. And grazing works in a way that is also natural and simple. The herbivores, or grazing and browsing animals, feed on tall grasses that block sunlight from reaching the ground, making the light available to other plants.That’s the key finding of a five-year study carried out at 40 different sites around the world and scheduled for online publication March 9, 2014 in the journal Nature. More than 50 scientists belonging to the Nutrient Network, a team of scientists studying grasslands worldwide, co-authored the study.”This study has tremendous significance because human activities are changing grasslands everywhere,” said study co-author Daniel S. Gruner, associate professor of entomology at the University of Maryland. “We’re over-fertilizing them, and we’re adding and subtracting herbivores. We have a worldwide experiment going on, but it’s completely uncontrolled.”Gruner, a member of the Nutrient Network (which participants have nicknamed NutNet) since its founding in 2006, helped plan the worldwide study and analyze its results. Elizabeth Borer of the University of Minnesota was the study’s lead author.The U.N. Food and Agricultural Organization estimates that grasslands cover between one-fifth and two-fifths of the planet’s land area and are home to more than one-tenth of humankind. But like all plant communities, grasslands are suffering from too much fertilizer.As humans burn fossil fuels, dose crops with chemical fertilizers, and dispose of manure from livestock, they introduce extra nitrogen and other nutrients into the soil, air and water. …

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NASA’s WISE survey finds thousands of new stars, but no ‘Planet X’

After searching hundreds of millions of objects across our sky, NASA’s Wide-Field Infrared Survey Explorer (WISE) has turned up no evidence of the hypothesized celestial body in our solar system commonly dubbed “Planet X.”Researchers previously had theorized about the existence of this large, but unseen celestial body, suspected to lie somewhere beyond the orbit of Pluto. In addition to “Planet X,” the body had garnered other nicknames, including “Nemesis” and “Tyche.”This recent study, which involved an examination of WISE data covering the entire sky in infrared light, found no object the size of Saturn or larger exists out to a distance of 10,000 astronomical units (au), and no object larger than Jupiter exists out to 26,000 au. One astronomical unit equals 93 million miles. Earth is 1 au, and Pluto about 40 au, from the sun.”The outer solar system probably does not contain a large gas giant planet, or a small, companion star,” said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.But searches of the WISE catalog are not coming up empty. A second study reveals several thousand new residents in our sun’s “backyard,” consisting of stars and cool bodies called brown dwarfs.”Neighboring star systems that have been hiding in plain sight just jump out in the WISE data,” said Ned Wright of the University of California, Los Angeles, the principal investigator of the mission.The second WISE study, which concentrated on objects beyond our solar system, found 3,525 stars and brown dwarfs within 500 light-years of our sun.”We’re finding objects that were totally overlooked before,” said Davy Kirkpatrick of NASA’s Infrared and Processing Analysis Center at the California Institute of Technology, Pasadena, Calif. Kirkpatrick is lead author of the second paper, also in the Astrophysical Journal. Some of these 3,525 objects also were found in the Luhman study, which catalogued 762 objects.The WISE mission operated from 2010 through early 2011, during which time it performed two full scans of the sky — with essentially a six-month gap between scans. The survey captured images of nearly 750 million asteroids, stars and galaxies. In November 2013, NASA released data from the AllWISE program, which now enables astronomers to compare the two full-sky surveys to look for moving objects.In general, the more an object in the WISE images appears to move over time, the closer it is. This visual clue is the same effect at work when one observes a plane flying low to the ground versus the same plane flying at higher altitude. …

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Plasma plumes help shield Earth from damaging solar storms

Earth’s magnetic field, or magnetosphere, stretches from the planet’s core out into space, where it meets the solar wind, a stream of charged particles emitted by the sun. For the most part, the magnetosphere acts as a shield to protect Earth from this high-energy solar activity.But when this field comes into contact with the sun’s magnetic field — a process called “magnetic reconnection” — powerful electrical currents from the sun can stream into Earth’s atmosphere, whipping up geomagnetic storms and space weather phenomena that can affect high-altitude aircraft, as well as astronauts on the International Space Station.Now scientists at MIT and NASA have identified a process in Earth’s magnetosphere that reinforces its shielding effect, keeping incoming solar energy at bay.By combining observations from the ground and in space, the team observed a plume of low-energy plasma particles that essentially hitches a ride along magnetic field lines — streaming from Earth’s lower atmosphere up to the point, tens of thousands of kilometers above the surface, where the planet’s magnetic field connects with that of the sun. In this region, which the scientists call the “merging point,” the presence of cold, dense plasma slows magnetic reconnection, blunting the sun’s effects on Earth.”The Earth’s magnetic field protects life on the surface from the full impact of these solar outbursts,” says John Foster, associate director of MIT’s Haystack Observatory. “Reconnection strips away some of our magnetic shield and lets energy leak in, giving us large, violent storms. These plasmas get pulled into space and slow down the reconnection process, so the impact of the sun on the Earth is less violent.”Foster and his colleagues publish their results in this week’s issue of Science. The team includes Philip Erickson, principal research scientist at Haystack Observatory, as well as Brian Walsh and David Sibeck at NASA’s Goddard Space Flight Center.Mapping Earth’s magnetic shieldFor more than a decade, scientists at Haystack Observatory have studied plasma plume phenomena using a ground-based technique called GPS-TEC, in which scientists analyze radio signals transmitted from GPS satellites to more than 1,000 receivers on the ground. Large space-weather events, such as geomagnetic storms, can alter the incoming radio waves — a distortion that scientists can use to determine the concentration of plasma particles in the upper atmosphere. Using this data, they can produce two-dimensional global maps of atmospheric phenomena, such as plasma plumes.These ground-based observations have helped shed light on key characteristics of these plumes, such as how often they occur, and what makes some plumes stronger than others. But as Foster notes, this two-dimensional mapping technique gives an estimate only of what space weather might look like in the low-altitude regions of the magnetosphere. To get a more precise, three-dimensional picture of the entire magnetosphere would require observations directly from space.Toward this end, Foster approached Walsh with data showing a plasma plume emanating from Earth’s surface, and extending up into the lower layers of the magnetosphere, during a moderate solar storm in January 2013. …

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Extreme weather caused by climate change decides distribution of insects, study shows

As climate change is progressing, the temperature of our planet increases. This is particularly important for the large group of animals that are cold-blooded (ectothermic), including insects. Their body temperature is ultimately determined by the ambient temperature, and the same therefore applies to the speed and efficiency of their vital biological processes.But is it changes in average temperature or frequency of extreme temperature conditions that have the greatest impact on species distribution? This was the questions that a group of Danish and Australian researchers decided to examine in a number of insect species.Johannes Overgaard, Department of Bioscience, Aarhus University, Denmark, Michael R. Kearney and Ary A. Hoffmann, Melbourne University, Australia, recently published the results of these studies in the journal Global Change Biology. The results demonstrate that it is especially the extreme temperature events that define the distribution of both tropical and temperate species. Thus climate change affects ectotermic animals primarily because more periods of extreme weather are expected in the future.Fruit flies were modeledThe researchers examined 10 fruit fly species of the genus Drosophila adapted to tropical and temperate regions of Australia. First they examined the temperatures for which the species can sustain growth and reproduction, and then they found the boundaries of tolerance for hot and cold temperatures.”This is the first time ever where we have been able to compare the effects of extremes and changes in average conditions in a rigorous manner across a group of species,” mentions Ary Hoffmann.Based on this knowledge and knowledge of the present distribution of the 10 species they then examined if distribution was correlated to the temperatures required for growth and reproduction or rather limited by their tolerance to extreme temperature conditions.”The answer was unambiguous: it is the species’ tolerance to very cold or hot days that define their present distribution,” says Johannes Overgaard.It is therefore the extreme weather events, such as heat waves or extremely cold conditions, which costs the insects their life, not an increase in average temperature.Drastic changes in storeWith this information in hand, the researchers could then model how distributions are expected to change if climate change continues for the next 100 years.Most terrestrial animals experience temperature variation on both daily and seasonal time scale, and they are adapted to these conditions. Thus, for a species to maintain its existence under varying temperature conditions there are two simple conditions that must be met. …

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Extreme weather images in the media cause fear and disengagement with climate change

The paper ‘ Images of Extreme Weather: Symbolising Human Responses to Climate Change’, by Brigitte Nerlich & Rusi Jaspal, published in Science as Culture, reveals that extreme weather images represent human suffering and loss. They are iconic of climate change and are symbols of its natural impacts.Reporting on extreme weather has increased over the last few years. In the past social scientists, and media and communication analysts have studied how climate change is depicted in the text of media and social media. While researchers have become increasingly interested in climate change images, they have not yet studied them with respect to symbolising certain emotions.The International Panel on Climate Change (IPCC) published a draft report on extreme weather and climate change adaptation. The report was covered in the news and illustrated with images. Some of these depicted ‘extreme weather’, in particular with relation to floods, droughts and heat waves, hurricanes and ice/sea-level rise.Researchers studied images published in the news to illustrate their coverage of the IPCC report. They used visual thematic analysis, examining the way they might symbolise certain emotional responses, such as compassion, fear, guilt, vulnerability, helpless, courage or resilience.Results showed that images of flooding displays people in the developing world ‘getting on with it’. It portrays individuals accustomed to flooding and that they can overcome the extreme weather. The images showed cheerful behaviour of those who are affected by flooding; lack of victimhood; engagement in their day-to-day activities and communal aspects of coping with flooding.New research has shown that images of extreme weather in the media create negative emotional meanings and might lead to disengagement with the issue of climate change. The images symbolised fear, helplessness and vulnerability and, in some cases, guilt and compassion. …

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Responding to potential asteroid redirect mission targets

One year ago, on Feb. 15, 2013, the world was witness to the dangers presented by near-Earth Objects (NEOs) when a relatively small asteroid entered Earth’s atmosphere, exploding over Chelyabinsk, Russia, and releasing more energy than a large atomic bomb. Tracking near-Earth asteroids has been a significant endeavor for NASA and the broader astronomical community, which has discovered 10,713 known near-Earth objects to date. NASA is now pursuing new partnerships and collaborations in an Asteroid Grand Challenge to accelerate NASA’s existing planetary defense work, which will help find all asteroid threats to human population and know what to do about them. In parallel, NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth’s moon for future exploration by astronauts in the 2020s.ARM will use capabilities in development, including the new Orion spacecraft and Space Launch System (SLS) rocket, and high-power Solar Electric Propulsion. All are critical components of deep-space exploration and essential to meet NASA’s goal of sending humans to Mars in the 2030s. The mission represents an unprecedented technological feat, raising the bar for human exploration and discovery, while helping protect our home planet and bringing us closer to a human mission to one of these intriguing objects.NASA is assessing two concepts to robotically capture and redirect an asteroid mass into a stable orbit around the moon. In the first proposed concept, NASA would capture and redirect an entire very small asteroid. In the alternative concept, NASA would retrieve a large, boulder-like mass from a larger asteroid and return it to this same lunar orbit. In both cases, astronauts aboard an Orion spacecraft would then study the redirected asteroid mass in the vicinity of the moon and bring back samples.Very few known near-Earth objects are ARM candidates. …

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Flowing water on Mars appears likely but hard to prove: Studies examine puzzling summertime streaks

Martian experts have known since 2011 that mysterious, possibly water-related streaks appear and disappear on the planet’s surface. Georgia Institute of Technology Ph.D. candidate Lujendra Ojha discovered them while an undergraduate at the University of Arizona. These features were given the descriptive name of recurring slope lineae (RSL) because of their shape, annual reappearance and occurrence generally on steep slopes such as crater walls. Ojha has been taking a closer look at this phenomenon, searching for minerals that RSL might leave in their wake, to try to understand the nature of these features: water-related or not?Ojha and Georgia Tech Assistant Professor James Wray looked at 13 confirmed RSL sites using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) images. They didn’t find any spectral signature tied to water or salts. But they did find distinct and consistent spectral signatures of ferric and ferrous minerals at most of the sites. The minerals were more abundant or featured distinct grain sizes in RSL-related materials as compared to non-RSL slopes.”We still don’t have a smoking gun for existence of water in RSL, although we’re not sure how this process would take place without water,” said Ojha. “Just like the RSL themselves, the strength of the spectral signatures varies according to the seasons. The signatures are stronger when it’s warmer and less significant when it’s colder.”The research team also notes that the lack of water-related absorptions rules out hydrated salts as a spectrally dominant phase on RSL slopes. …

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One planet, two stars: New research shows how circumbinary planets form

Luke Skywalker’s home planet Tatooine would have formed far from its current location in the Star Wars universe, a new University of Bristol study into its real world counterparts, observed by the Kepler space telescope, suggests.Like the fictional Star Wars planet, Kepler-34(AB)b is a circumbinary planet, so-called because its orbit encompasses two stars. There are few environments more extreme than a binary star system in which planet formation can occur. Powerful gravitational perturbations from the two stars on the rocky building blocks of planets lead to destructive collisions that grind down the material. So, how can the presence of such planets be explained?In research published this week in Astrophysical Journal Letters, Dr Zoe Leinhardt and colleagues from Bristol’s School of Physics have completed computer simulations of the early stages of planet formation around the binary stars using a sophisticated model that calculates the effect of gravity and physical collisions on and between one million planetary building blocks.They found that the majority of these planets must have formed much further away from the central binary stars and then migrated to their current location.Dr Leinhardt said: “Our simulations show that the circumbinary disk is a hostile environment even for large, gravitationally strong objects. Taking into account data on collisions as well as the physical growth rate of planets, we found that Kepler 34(AB)b would have struggled to grow where we find it now.”Based on these conclusions for Kepler-34, it seems likely that all of the currently known circumbinary planets have also migrated significantly from their formation locations — with the possible exception of Kepler-47 (AB)c which is further away from the binary stars than any of the other circumbinary planets.Stefan Lines, lead author of the study, said: “Circumbinary planets have captured the imagination of many science-fiction writers and film-makers — our research shows just how remarkable such planets are. Understanding more about where they form will assist future exoplanet discovery missions in the hunt for earth-like planets in binary star systems.”Story Source:The above story is based on materials provided by University of Bristol. Note: Materials may be edited for content and length.

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Rings, dark side of Saturn glow in new Cassini image

Oct. 21, 2013 — The gauzy rings of Saturn and the dark side of the planet glow in newly released infrared images obtained by NASA’s Cassini spacecraft.”Looking at the Saturn system when it is backlit by the sun gives scientists a kind of inside-out view of Saturn that we don’t normally see,” said Matt Hedman, a participating scientist based at the University of Idaho, Moscow, Idaho. “The parts of Saturn’s rings that are bright when you look at them from backyard telescopes on Earth are dark, and other parts that are typically dark glow brightly in this view.”It can be difficult for scientists to get a good look at the faint outer F, E and G rings, or the tenuous inner ring known as the D ring when light is shining directly on them. That’s because they are almost transparent and composed of small particles that do not reflect light well. What’s different about this viewing geometry?When these small particles are lit from behind, they show up like fog in the headlights of an oncoming vehicle. The C ring also appears relatively bright here; not because it is made of dust, but because the material in it — mostly dirty water ice — is translucent. In fact, in the 18th and 19th centuries, it was known as the “crepe ring” because of its supposed similarity to crepe paper. The wide, middle ring known as the B ring — one of the easiest to see from Earth through telescopes because it is densely packed with chunks of bright water ice — looks dark in these images because it is so thick that it blocks almost all of the sunlight shining behind it. Infrared images also show thermal, or heat, radiation. While a visible-light image from this vantage point would simply show the face of the planet as dimly lit by sunlight reflected off the rings, Saturn glows brightly in this view because of heat from Saturn’s interior.In a second version of the image, scientists “stretched” or exaggerated the contrast of the data, which brings out subtleties not initially visible.Structures in the wispy E ring — made from the icy breath of the moon Enceladus — reveal themselves in this exaggerated view. …

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Why are some corals flourishing in a time of global warming?

Sep. 10, 2013 — As Earth’s temperature climbs, the stony corals that form the backbone of ocean reefs are in decline.It’s a well-documented story: Violent storms and coral bleaching have all contributed to dwindling populations, and increasing acidity of seawater threatens to take an additional toll.Less discussed, however, is the plight of gorgonian corals — softer, flexible, tree-like species that can rise up like an underwater forest, providing a canopy beneath which small fish and aquatic life of all kinds can thrive.Divers have noted in recent years that gorgonian corals seem to be proliferating in certain areas of the Caribbean, even as their stony counterparts struggle. Now, a new study will look to quantify this phenomenon.Scientists from the California State University, Northridge and University at Buffalo will examine 27 years of photographs from reefs off the Caribbean island of St. John to determine how gorgonian numbers have changed, and run field experiments to see how competition with stony corals — or a lack of it — influences gorgonian growth.The study will also document what gorgonian coral populations look like now at St. John, which is part of the U.S. Virgin Islands, and track future development there.Understanding coral reefs is important as they are one of the planet’s most biologically diverse ecosystems.”When you look at these gorgonian corals, it seems that they’re increasing in abundance, and that’s an anecdotal observation that many people have made,” said UB geology professor Howard Lasker, one of three investigators heading the project. “Does this mean that as stony corals continue to decline, we’re going to see reefs transforming into these gorgonian coral-dominated communities? That’s what we’re trying to find out.””With climate change and ocean acidification, there certainly is a realistic possibility that coral reefs as we know them could pretty much disappear,” said Cal State Northridge biology professor Peter Edmunds, another principal investigator. “The question is, what will coral reefs look like in the future?”The nearly $1 million project, funded by the National Science Foundation (NSF), started officially on Sept. 1.It brings together a powerful team. …

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Gravity variations over Earth much bigger than previously thought

Sep. 4, 2013 — A joint Australian-German research team led by Curtin University’s Dr Christian Hirt has created the highest-resolution maps of Earth’s gravity field to date — showing gravitational variations up to 40 per cent larger than previously assumed.Using detailed topographic information obtained from the US Space Shuttle, a specialist team including Associate Professor Michael Kuhn, Dr Sten Claessens and Moritz Rexer from Curtin’s Western Australian Centre for Geodesy and Professor Roland Pail and Thomas Fecher from Technical University Munich improved the resolution of previous global gravity field maps by a factor of 40.”This is a world-first effort to portray the gravity field for all countries of our planet with unseen detail,” Dr Hirt said.”Our research team calculated free-fall gravity at three billion points — that’s one every 200 metres — to create these highest-resolution gravity maps. They show the subtle changes in gravity over most land areas of Earth.”The new gravity maps revealed the variations of free-fall gravity over Earth were much bigger than previously thought.Earth’s gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes, and largest near the North Pole.”Only a few years ago, this research would not have been possible,” Dr Hirt said.”The creation of the maps would have required about 80 years of office PC computation time but advanced supercomputing provided by the Western Australian iVEC facility helped us to complete the maps within a few months.”High-resolution gravity maps are required in civil engineering, for instance, for building of canals, bridges and tunnels. The mining industry could also benefit.”The maps can be used by surveyors and other spatial science professionals to precisely measure topographic heights with satellite systems such as the Global Positioning System (GPS),” Dr Hirt said.The findings of the research team from Curtin and Technical University Munich have recently appeared in the journal Geophysical Research Letters.Earth’s gravity field gallery: http://geodesy.curtin.edu.au/research/models/GGMplus/gallery.cfm

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‘Trojan’ asteroids in far reaches of solar system more common than previously thought

Aug. 29, 2013 — UBC astronomers have discovered the first Trojan asteroid sharing the orbit of Uranus, and believe 2011 QF99 is part of a larger-than-expected population of transient objects temporarily trapped by the gravitational pull of the Solar System’s giant planets.Trojans are asteroids that share the orbit of a planet, occupying stable positions known as Lagrangian points. Astronomers considered their presence at Uranus unlikely because the gravitational pull of larger neighbouring planets would destabilize and expel any Uranian Trojans over the age of the Solar System.To determine how the 60 kilometre-wide ball of rock and ice ended up sharing an orbit with Uranus the astronomers created a simulation of the Solar System and its co-orbital objects, including Trojans.”Surprisingly, our model predicts that at any given time three per cent of scattered objects between Jupiter and Neptune should be co-orbitals of Uranus or Neptune,” says Mike Alexandersen, lead author of the study to be published tomorrow in the journal Science. This percentage had never before been computed, and is much higher than previous estimates.Several temporary Trojans and co-orbitals have been discovered in the Solar System during the past decade. QF99 is one of those temporary objects, only recently (within the last few hundred thousand years) ensnared by Uranus and set to escape the planet’s gravitational pull in about a million years.”This tells us something about the current evolution of the Solar System,” says Alexandersen. “By studying the process by which Trojans become temporarily captured, one can better understand how objects migrate into the planetary region of the Solar System.”UBC astronomers Brett Gladman, Sarah Greenstreet and colleagues at the National Research Council of Canada and Observatoire de Besancon in France were part of the research team.

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Climate change occurring ten times faster than at any time in past 65 million years

Aug. 1, 2013 — The planet is undergoing one of the largest changes in climate since the dinosaurs went extinct. But what might be even more troubling for humans, plants and animals is the speed of the change. Stanford climate scientists warn that the likely rate of change over the next century will be at least 10 times quicker than any climate shift in the past 65 million years.If the trend continues at its current rapid pace, it will place significant stress on terrestrial ecosystems around the world, and many species will need to make behavioral, evolutionary or geographic adaptations to survive.Although some of the changes the planet will experience in the next few decades are already “baked into the system,” how different the climate looks at the end of the 21st century will depend largely on how humans respond.The findings come from a review of climate research by Noah Diffenbaugh, an associate professor of environmental Earth system science, and Chris Field, a professor of biology and of environmental Earth system science and the director of the Department of Global Ecology at the Carnegie Institution. The work is part of a special report on climate change in the current issue of Science.Diffenbaugh and Field, both senior fellows at the Stanford Woods Institute for the Environment, conducted the targeted but broad review of scientific literature on aspects of climate change that can affect ecosystems, and investigated how recent observations and projections for the next century compare to past events in Earth’s history.For instance, the planet experienced a 5 degree Celsius hike in temperature 20,000 years ago, as Earth emerged from the last ice age. This is a change comparable to the high-end of the projections for warming over the 20th and 21st centuries.The geologic record shows that, 20,000 years ago, as the ice sheet that covered much of North America receded northward, plants and animals recolonized areas that had been under ice. As the climate continued to warm, those plants and animals moved northward, to cooler climes.”We know from past changes that ecosystems have responded to a few degrees of global temperature change over thousands of years,” said Diffenbaugh. “But the unprecedented trajectory that we’re on now is forcing that change to occur over decades. That’s orders of magnitude faster, and we’re already seeing that some species are challenged by that rate of change.”Some of the strongest evidence for how the global climate system responds to high levels of carbon dioxide comes from paleoclimate studies. Fifty-five million years ago, carbon dioxide in the atmosphere was elevated to a level comparable to today. …

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Planetary ‘runaway greenhouse’ more easily triggered, research shows

July 30, 2013 — It might be easier than previously thought for a planet to overheat into the scorchingly uninhabitable “runaway greenhouse” stage, according to new research by astronomers at the University of Washington and the University of Victoria published July 28 in the journal Nature Geoscience.In the runaway greenhouse stage, a planet absorbs more solar energy than it can give off to retain equilibrium. As a result, the world overheats, boiling its oceans and filling its atmosphere with steam, which leaves the planet glowing-hot and forever uninhabitable, as Venus is now.One estimate of the inner edge of a star’s “habitable zone” is where the runaway greenhouse process begins. The habitable zone is that ring of space around a star that’s just right for water to remain in liquid form on an orbiting rocky planet’s surface, thus giving life a chance.Revisiting this classic planetary science scenario with new computer modeling, the astronomers found a lower thermal radiation threshold for the runaway greenhouse process, meaning that stage may be easier to initiate than had been previously thought.”The habitable zone becomes much narrower, in the sense that you can no longer get as close to the star as we thought before going into a runaway greenhouse,” said Tyler Robinson, a UW astronomy postdoctoral researcher and second author on the paper. The lead author is Colin Goldblatt of the University of Victoria.Though further research is called for, the findings could lead to a recalibration of where the habitable zone begins and ends, with some planets having their candidacy as possible habitable worlds revoked.”These worlds on the very edge got ‘pushed in,’ from our perspective — they are now beyond the runaway greenhouse threshold,” Robinson said.Subsequent research, the astronomers say, is needed in part because their computer modeling was done in a “single-column, clear-sky model,” or a one-dimensional measure averaged around a planetary sphere that does not account for the atmospheric effect of clouds.The findings apply to planet Earth as well. As the sun increases in brightness over time, Earth, too, will move into the runaway greenhouse stage — but not for a billion and a half years or so. Still, it inspired the astronomers to write, “As the solar constant increases with time, Earth’s future is analogous to Venus’s past.”Other co-authors are Kevin J. Zahnle of the NASA Ames Research Center in Moffett Field, Calif.; and David Crisp of the Jet Propulsion Laboratory in Pasadena, Calif.

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NASA’s Chandra sees eclipsing planet in X-rays for first time

July 29, 2013 — For the first time since exoplanets, or planets around stars other than the sun, were discovered almost 20 years ago, X-ray observations have detected an exoplanet passing in front of its parent star.An advantageous alignment of a planet and its parent star in the system HD 189733, which is 63 light-years from Earth, enabled NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM Newton Observatory to observe a dip in X-ray intensity as the planet transited the star.”Thousands of planet candidates have been seen to transit in only optical light,” said Katja Poppenhaeger of Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., who led a new study to be published in the Aug. 10 edition of The Astrophysical Journal. “Finally being able to study one in X-rays is important because it reveals new information about the properties of an exoplanet.”The team used Chandra to observe six transits and data from XMM Newton observations of one.The planet, known as HD 189733b, is a hot Jupiter, meaning it is similar in size to Jupiter in our solar system but in very close orbit around its star. HD 189733b is more than 30 times closer to its star than Earth is to the sun. It orbits the star once every 2.2 days.HD 189733b is the closest hot Jupiter to Earth, which makes it a prime target for astronomers who want to learn more about this type of exoplanet and the atmosphere around it. They have used NASA’s Kepler space telescope to study it at optical wavelengths, and NASA’s Hubble Space Telescope to confirm it is blue in color as a result of the preferential scattering of blue light by silicate particles in its atmosphere.The study with Chandra and XMM Newton has revealed clues to the size of the planet’s atmosphere. The spacecraft saw light decreasing during the transits. The decrease in X-ray light was three times greater than the corresponding decrease in optical light.”The X-ray data suggest there are extended layers of the planet’s atmosphere that are transparent to optical light but opaque to X-rays,” said co-author Jurgen Schmitt of Hamburger Sternwarte in Hamburg, Germany. “However, we need more data to confirm this idea.”The researchers also are learning about how the planet and the star can affect one another.Astronomers have known for about a decade ultraviolet and X-ray radiation from the main star in HD 189733 are evaporating the atmosphere of HD 189733b over time. The authors estimate it is losing 100 million to 600 million kilograms of mass per second. …

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‘International beam team’ solves Martian meteorite-age puzzle

July 24, 2013 — By directing energy beams at tiny crystals found in a Martian meteorite, a Western University-led team of geologists has proved that the most common group of meteorites from Mars is almost 4 billion years younger than many scientists had believed — resolving a long-standing puzzle in Martian science and painting a much clearer picture of the Red Planet’s evolution that can now be compared to that of habitable Earth.In a paper published today in the journal Nature, lead author Desmond Moser, an Earth Sciences professor from Western’s Faculty of Science, Kim Tait, Curator, Mineralogy, Royal Ontario Museum, and a team of Canadian, U.S., and British collaborators show that a representative meteorite from the Royal Ontario Museum (ROM)’s growing Martian meteorite collection, started as a 200 million-year-old lava flow on Mars, and contains an ancient chemical signature indicating a hidden layer deep beneath the surface that is almost as old as the solar system.The team, composed of scientists from ROM, the University of Wyoming, UCLA, and the University of Portsmouth, also discovered crystals that grew while the meteorite was launched from Mars towards Earth, allowing them to narrow down the timing to less than 20 million years ago while also identifying possible launch locations on the flanks of the supervolcanoes at the Martian equator.More details can be found in their paper titled, “Solving the Martian meteorite age conundrum using micro-baddeleyite and launch-generated zircon.”Moser and his group at Western’s Zircon & Accessory Phase Laboratory (ZAPLab), one of the few electron nanobeam dating facilities in the world, determined the growth history of crystals on a polished surface of the meteorite. The researchers combined a long-established dating method (measuring radioactive uranium/lead isotopes) with a recently developed gently-destructive, mineral grain-scale technique at UCLA that liberates atoms from the crystal surface using a focused beam of oxygen ions.Moser estimates that there are roughly 60 Mars rocks dislodged by meteorite impacts that are now on Earth and available for study, and that his group’s approach can be used on these and a much wider range of heavenly bodies.”Basically, the inner solar system is our oyster. We have hundreds of meteorites that we can apply this technique to, including asteroids from beyond Mars to samples from the Moon,” says Moser, who credits the generosity of the collectors that identify this material and make it available for public research.

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