SPACE & EARTH

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Cassini Spacecraft Reveals 101 Geysers & more on Icy Saturn Moon
Enceladus' geyser-active fractures | July 28, 2014: This artist's rendering shows a cross-section of the ice shell immediately beneath one of Enceladus' geyser-active fractures, illustrating the physical and thermal structure and the processes ongoing below and at the surface.

Scientists using mission data from NASA’s Cassini spacecraft have identified 101 distinct geysers erupting on Saturn’s icy moon Enceladus. Their analysis suggests it is possible for liquid water to reach from the moon’s underground sea all the way to its surface.
These findings, and clues to what powers the geyser eruptions, are presented in two articles published in the current online edition of the Astronomical Journal.

Over a period of almost seven years, Cassini’s cameras surveyed the south polar terrain of the small moon, a unique geological basin renowned for its four prominent "tiger stripe” fractures and the geysers of tiny icy particles and water vapor first sighted there nearly 10 years ago. The result of the survey is a map of 101 geysers, each erupting from one of the tiger stripe fractures, and the discovery that individual geysers are coincident with small hot spots. These relationships pointed the way to the geysers’ origin.

After the first sighting of the geysers in 2005, scientists suspected repeated flexing of Enceladus by Saturn’s tides as the moon orbits the planet had something to do with their behavior. One suggestion included the back-and-forth rubbing of opposing walls of the fractures generating frictional heat that turned ice into geyser-forming vapor and liquid.

Alternate views held that the opening and closing of the fractures allowed water vapor from below to reach the surface. Before this new study, it was not clear which process was the dominating influence. Nor was it certain whether excess heat emitted by Enceladus was everywhere correlated with geyser activity.

To determine the surface locations of the geysers, researchers employed the same process of triangulation used historically to survey geological features on Earth, such as mountains. When the researchers compared the geysers’ locations with low-resolution maps of thermal emission, it became apparent the greatest geyser activity coincided with the greatest thermal radiation. Comparisons between the geysers and tidal stresses revealed similar connections. However, these correlations alone were insufficient to answer the question, “What produces what?”

The answer to this mystery came from comparison of the survey results with high-resolution data collected in 2010 by Cassini’s heat-sensing instruments. Individual geysers were found to coincide with small-scale hot spots, only a few dozen feet (or tens of meters) across, which were too small to be produced by frictional heating, but the right size to be the result of condensation of vapor on the near-surface walls of the fractures. This immediately implicated the hot spots as the signature of the geysering process.

“Once we had these results in hand we knew right away heat was not causing the geysers, but vice versa,” said Carolyn Porco, leader of the Cassini imaging team from the Space Science Institute in Boulder, Colorado, and lead author of the first paper. “It also told us the geysers are not a near-surface phenomenon, but have much deeper roots.”

Thanks to recent analysis of Cassini gravity data, the researchers concluded the only plausible source of the material forming the geysers is the sea now known to exist beneath the ice shell. They also found that narrow pathways through the ice shell can remain open from the sea all the way to the surface, if filled with liquid water.  

In the companion paper, the authors report the brightness of the plume formed by all the geysers, as seen with Cassini’s high resolution cameras, changes periodically as Enceladus orbits Saturn.  Armed with the conclusion the opening and closing of the fractures modulates the venting, the authors compared the observations with the expected venting schedule due to tides.

They found the simplest model of tidal flexing provides a good match for the brightness variations Cassini observes, but it does not predict the time when the plume begins to brighten. Some other important effect is present and the authors considered several in the course of their work.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the United States, England, France and Germany. The imaging team is based at the Space Science Institute.

Credit: NASA/JPL

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Friday Focus: How Texas’ new solar institute is planning to take on the world

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  Texas A&M's Center for Solar Energy is setting out to become the world's largest solar research centre.
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  CSE is aiming to help the US become a world leader in solar.

Blogger

Lucy Woods

Following Obama’s climate action plan the US has begun flag-staking for solar, pumping investment and changing policies to put solar energy at the top: and America at the top of solar.
As the US jumps full bound into dominating solar and international solar companies look for a slice of the action, a flurry of recent announcements suggests the country is also looking to take a lead in the sphere of solar research and academia.

Earlier this month, Texas A&M University revealed grand plans for what it said would be the “world’s largest” solar research institute in the form of the US$600 million Center for Solar Energy (CSE). And hot on its heels, State University New York (SUNY) said it was planning to open a US$100 million new PV manufacturing and development research centre in New York this year.
CSE’s ambitions as the answer to the US solar industry’s problems are indeed impressive. Its promotional video unleashes a barrage of catastrophic facts: the US controlling just 7% of the world solar market when in 1995 it controlled 50%; 90% of solar products coming from outside the US; 2,000 jobs lost; the world spending 500 times more on solar than the US. Will the US be left behind, it asks, or will it regain its “rightful place through innovation and leadership?”
Urgent and inspiring quotes from prominent economists and business leaders make the message clear: America must win the international solar leadership battle, as “the country that can answer the [solar] call will be the force to be reckoned with”.The CSE video questions: “Will we rise to the occasion?” CSE “can and will answer that call,” comes the response.

In short, CSE is shooting for nothing short of being the school for solar, offering the biggest and best of everything: the largest pure solar PV research facility in the world; the only utility-scale test site in the world; the largest exclusively solar PV innovation lab globally; the most technologies deployed anywhere. Alongside all of this, CSE pledges to generate 100% of the campus’ energy from its own 50MW plant.

The US$600 million venture is being majority funded by “venture philanthropy” and government bursaries; it has already secured its first venture partner, but is far from fully funded. CSE subsequently welcomes conversations with technologies corporate groups, other institutions, and venture capitalists and of course philanthropists.

Money aside, CSE’s primary focus will be on education, then job creation with career training, engineering research specialities including cell architecture, optics, ion implantation, 3D printing and advanced manufacturing methods among others.

But with an impressive list of international solar institutes already established across the globe, will CSE ever be able to live up to its grand ambitions?
Mark Thirsk, managing partner at Linx Consulting for electric materials, believes CSE will still find it hard to overtake other established centres such as America’s National Renewable Energy Laboratory, or Germany’s Fraunhofer Institute to become a global leaders.

But he commends CSE’s focus on next-generation research technologies and predicts CSE may “help tip solar installations into becoming sure-fire money makers eventually, but those gains remain a few years away”.

And what about the cost? Fraunhofer’s expenditure over four years was less than half, at approximately US$270 million, while NREL’s expenditure in 2009 was US$316 million.
“The headline number is impressive, but it sounds as if some of the money will be invested in a ground-based array rather than in research,” concludes Thirsk.

Raju Yenamandra, vice president of business development at manufacturer SolarWorld USA, reckons only 25% of the US$600 million figure will be spent on the in-house array, but admits the “devil is in the detail” as announcements so far are not detailed enough for a full insight. Yenamandra doesn’t imagine CSE will be frivolous with its budget though, as it won’t want to be “pounced” on by critics if seen to be splashing money around.

Yenamandra mainly sings CSE’s praise for bringing practical solar to academia, offering a side-by-side comparison for installation approaches. And he predicts that if the institute can make enough money from its 50MW solar plant, it will be able to fulfil its ambitions. CSE plans to sell spare electricity from the plant to the national grid to provide Texans outside the campus walls with clean, green, cheap energy.

For America as a whole Yenamandra thinks CSE will help promote and advertise solar to the general public, as the “population is more likely to embrace solar if it is from a university”. CSE plans to provide independent verifications and breakdowns of solar products to make it clear what has been proven and what is viable in solar energy.

But what seems to define Texas A&M from other universities is its sheer boldness, says Yenamandra. Where other universities he believes are shy and purely technology and theory focused, CSE will be actively applying and installing (and gaining grants and credibility on the way).
Which is good news for graduates – Yenamandra confirms Solarworld USA would value CSE graduates as having an “edge” over others for practical work experience in the solar field, and would hope training times could therefore be minimised, accelerating solar advancement as a whole.
CSE will also run a solar entrepreneurship programme lasting two years aimed at amateurs and established solar professionals. Students are promised the chance to work with cutting edge technology teams and to learn how to start and run a global solar company.

There are also ten scholarships offered per company, with participants given the chance to live in CSE, refine their technology, train in solar business, acquire additional talent and hit the ground at a full run ready for an advanced venture capital investment - leaving the inventors and entrepreneurs in charge of their company, and the technology.

As for CSE’s ambition of America becoming a world leader in solar again, Yenamandra doesn’t think CSE will help it to overtake China in terms of solar production.
But with such bold ambitions, it is hard not to be won over by CSE’s vision of becoming the biggest and best solar research institute in the world.

At least for now anyway.

U.S. Geological Survey (USGS)

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Marked Prairie Dog — The chin of an anesthetized prairie dog in Wind Cave National Park, South Dakota is marked before the animal is released back into the wild.

Over 30 organizations and agencies are testing a USGS-developed oral vaccine to prevent the spread of plague in prairie dogs. If successful, the sylvatic plague vaccine could help protect endangered black-footed ferrets in the western U.S. because the ferrets rely on prairie dogs for food.

A veterinarian tags each trapped prairie dog and takes hair, whisker, and blood samples before scientists release the animals. Chin markings help scientists determine whether certain trapped prairie dogs had been previously tested. If markings are present on a trapped animal, that animal is immediately released without further testing. Photo credit: Marisa Lubeck, USGS.

U.S. Geological Survey (USGS)'s photos

 

Good Reasons for "Believing" in God - Dan Dennett, AAI 2007

Dan Dennett's talk at the AAI 2007 Conference in Washington, D.C. He is presented with the 2007 Richard Dawkins award at the introduction.
https://www.youtube.com/watch?v=BvJZQwy9dvE

Study Sheds New Light on Extinction of Dinosaurs

Jul 28, 2014 by Sci-News.com

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According to a study published in the journal Biological Reviews, non-avian dinosaurs might have survived the impact of a large bolide about 66 million years ago if it had happened a few million years earlier or later.

This image shows two individuals of Qianzhousaurus sinensis and a small feathered dinosaur called Nankangia. Image credit: Chuang Zhao.

“There has long been intense scientific debate about the cause of the dinosaur extinction,” said Dr Richard Butler from the University of Birmingham, who is a co-author on the study.
“Although our research suggests that dinosaur communities were particularly vulnerable at the time the asteroid hit, there is nothing to suggest that dinosaurs were doomed to extinction. Without that asteroid, the dinosaurs would probably still be here, and we very probably would not.”
“The dinosaurs were victims of colossal bad luck,” added Dr Steve Brusatte of the University of Edinburgh, the lead author on the study.
“Not only did a giant asteroid strike, but it happened at the worst possible time, when their ecosystems were vulnerable. Our new findings help clarify one of the enduring mysteries of science.”
Dr Brusatte and his colleagues studied an updated catalogue of dinosaur fossils, mostly from North America, to create a picture of how dinosaurs changed over the few million years before the asteroid hit.
The team found that in the few million years before a large bolide (comet or asteroid) struck what is now Mexico, Earth was experiencing environmental upheaval. This included extensive volcanic activity, changing sea levels and varying temperatures.
At this time, the dinosaurs’ food chain was weakened by a lack of diversity among the large herbivorous dinosaurs on which others preyed. This was probably because of changes in the environment and climate.
This created a perfect storm of events in which non-avian dinosaurs were vulnerable and unlikely to survive the aftermath of the asteroid strike.
As food chains collapsed, this would have wiped out the dinosaur kingdom one species after another.
The only dinosaurs to survive were those who could fly, which evolved to become the birds of today.
The scientists said if the asteroid had struck a few million years earlier, when the range of dinosaur species was more diverse and food chains were more robust, or later, when new species had time to evolve, then they very likely would have survived.
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Stephen L. Brusatte et al. The extinction of the dinosaurs. Biological Reviews, published online July 28, 2014; doi: 10.1111/brv.12128

Reading Climate Change in the Leaves

An ecologist records nature's color signals to understand the feedback between plants and a changing climate.

By Josie Garthwaite|Tuesday, May 27, 2014

 

Andrew Richardson installs instruments 115 feet up in the Harvard Forest. 

Courtesy Donald Aubrecht

A silver station wagon loaded with climbing gear, computers, electrical wiring and a few scientists from Harvard University stops near a stand of pine and oak trees in the Harvard Forest, about 70 miles west of campus. Physiological ecologist Andrew Richardson, leader of this expedition, slips from the driver’s seat and grabs gear to ascend a metal tower among the trees. Its peak affords
Richardson a clear view of his living laboratory: the forest canopy.

Above the treetops, he checks a cluster of instruments that analyze the lush canopy as a collection of numbers: the amount of carbon being inhaled from the atmosphere, the concentration of water vapor in the air and the precise mix of hues the leaves exhibit.

Different pigments serve different functions: Green chlorophyll, which dominates during the growing season, absorbs light energy for photosynthesis, the conversion of carbon and water to sugar. In the shortening days of autumn, red anthocyanins and yellow carotenoids take over to help protect leaves against light damage.

To document this subtle seasonal color change, a webcam atop the tower snaps high-resolution images of the canopy every 30 minutes from dawn to dusk and uploads them to an online database.
During the past decade, Richardson has spearheaded an effort to install more than 80 such cameras at sites across North America, from the arctic tundra near northern Alaska’s Toolik Lake to the tropical grasslands surrounding Hawaii’s towering Mauna Kea. 

This PhenoCam Network amasses thousands of photos per day. Over time, Richardson hopes the resulting trove of color data will help scientists understand — and better predict — how ecosystems like the Harvard Forest respond to changes in the climate. 

Fall colors in the Harvard Forest on any given day (Oct. 9 in this case) vary from year to year, depending on temperature and rainfall.

Courtesy of Andrew Richardson/PhenoCam Network (3)

A Pulsating Palette

Over the course of millennia, white snow cover, vibrant autumn foliage and bright bursts of green have punctuated the rhythmic cycles of winter frosts, spring showers and long, warm summer days. Animals have evolved to be in sync with seasonal change: They bring young into the world just as nutritious green sprouts emerge in spring, and molt to blend in with winter whites and summer green-browns. It’s an intricate dance scientists refer to as phenology.

Richardson’s efforts to decipher this color code began in the 1990s, shortly after his return from an eight-month trek in Canada’s Yukon Territory. “It was the vegetation, the transition from forest to tundra and how the colors changed through the seasons that really captivated me,” he recalls.
Richardson had recently abandoned pursuit of a Ph.D. in economics at MIT and found himself in awe of nature’s colorful clockwork — so much so that he redirected his studies. 

Richardson enrolled in Yale University’s forestry program in 1996 and a few years later threw himself into a project lopping off balsam fir and red spruce branches in the White Mountains. He measured how much light the needles reflected in different wavelengths. This is an indicator of stress and “a very precise way of measuring color,” he explains.

Richardson showed that needles in the harsh, resource-poor high altitudes invested in stress-protection pigments to cope with wind, cold and blazing sun. 

Reading the Leaves

“Phenology is really sensitive to weather,” Richardson explains. “If it’s a cold spring, leaves will come out later. If it’s a warm spring, that will happen earlier.” 

Forests in the United States absorb and store more than 750 million metric tons of carbon dioxide each year, or more than 10 percent of national carbon emissions. Warmer temperatures triggering earlier green sprouts could produce a longer growing season in some places and more photosynthesis — and thus more carbon uptake. But early growth followed by frost or drought could damage fragile sprouts and reduce the amount of carbon that certain plants are able to absorb. Some species also respond to warming by fast-forwarding through their life cycles, narrowing the window for photosynthesis and carbon uptake.

Nature’s color palette already shows effects of climate change. Along the East Coast, where the “green wave” of spring leaves sprouting from maples, oaks and poplars historically has rolled from Miami to Maine in 75 days, atmospheric scientists with Princeton University predict the wave could take just 59 days by the end of the century. In parts of New England, fall colors arrive a few days later than they did 20 years ago, and the reds are more muted as autumn temperatures in the region warm.

But scientists don’t know what new rhythms will arise across different regions  — whether bursts of green will be brighter but shorter-lasting, for example, or more muted but longer-lasting. Nor do they know what such changes mean for the food web; for life-cycle events like migration, breeding and nesting; for the amount of moisture that trees will suck from the soil; or for the amount of carbon dioxide stored by plants.

That’s what Richardson hopes to tease out. “As we build up a big archive — warm years, cold years, wet years and dry years — we can use the data to develop models of how weather and phenology are related,” he says. These models can then be mapped against climate forecasts to predict how phenology could shift in the future, painting a picture of landscapes in a world of warmer temperatures, altered precipitation and humidity, and changes in cloud cover. “We want to use phenology as a biological indicator of the impacts of climate change on ecosystems,” Richardson says.

Richardson climbs a tower in New Hampshire’s White Mountains to repair a wireless network.

Courtesy Mariah Carbone

Cameras Rolling

Webcams offer a cheap way to monitor foliage at a local scale across a broad geographic range. “These pictures give you this permanent record,” Richardson says. “I can see what it was like on any day. I can go back to other years and compare, and tell you how things are different between those two years.” 

Scientists have used satellite-mounted sensors to indirectly measure vegetative growth around the globe for decades. But cloud cover and other atmospheric clutter often muddle the data. A study published in Nature in February suggests that previous models based on satellite data have overestimated greenness during dry seasons in the Amazon rainforest. Shadows, which shorten over the course of the tropical dry season, produce an optical illusion: Leaves reflect more light in the infrared spectrum, even as their actual greenness declines. 

Researchers need ground-level measurements like those of the PhenoCam Network to validate
remotely gathered information and refine the algorithms used to evaluate it. Richardson’s work complements field observations by researchers like Harvard ecologist John O’Keefe, who visited the same trees in the Harvard Forest every few days for more than 20 years, starting in the 1990s, to track the opening of buds in springtime and autumn leaf coloration. Last year Richardson’s team analyzed O’Keefe’s historic data set and found that most local tree species will likely display fall colors for longer durations and at higher intensity in coming years.

A decade and a half after Richardson’s shift to ecology, he has come to see leaf color the way an economist might view a financial statement. “It tells you a lot about the physiology of the leaf,” he says. 

Eighty-two feet up the tower, Richardson emerges above the dark understory of the Harvard Forest to feel a flush of sunlight and a flick of breeze on his face. “The views from the top are fantastic,” he says, “and this motivates a lot of what I do.” His methodical quest to decode the phenological rainbow has a way of propelling itself forward. As Aldo Leopold, who doggedly recorded seasonal signposts in Wisconsin in the 1930s and ’40s, once wrote: “Keeping records enhances the pleasure of the search, and the chance of finding order and meaning in these events.”

[This article originally appeared in print as "Cracking the Climate Color Code."]

Early Cretaceous Bloodsucking Bugs Found in China

July 26, 2014 | by Janet Fang

Photo credit: Flexicorpus acutirostratus / Y. Yao et al., Current Biology 2014

       

Fossilized blood-feeding bugs have been discovered in early Cretaceous sediments in China. That means at least one lineage of bloodsuckers was around 30 million years earlier than we thought. They may have even fed from dinosaurs. According to the study published in Current Biology this week, the fossils represent two new species, and they’re the earliest evidence of blood-feeding “true bugs.”

True bugs (order Hemiptera) have a mouthpart designed for sucking fluids, called the proboscis. But unlike proboscis-wielding butterflies or honeybees, true bugs can’t roll up their mouthparts. Modern true bugs include nasty bed bugs. As annoying and ubiquitous as they seem, blood-feeders (also called hematophages) are relatively uncommon among modern insects. They’re mostly found in just four orders: lice, fleas, true flies (including mosquitoes), and true bugs. The latter three have been documented prior to the Cenozoic.

It’s been hard to tell hematophages apart from their non-blood-feeding relatives in the patchy insect fossil record. Until now, only one hematophagous true bug, Quasicimex eilapinastes, has been described, from mid-Cretaceous amber in Myanmar, about 100 million years ago.
Working in the early Cretaceous Yixian Formation of Northeastern China, a team led by Yunzhi Yao and Dong Ren of Capital Normal University in Beijing studied nearly 400 insects. In seven true bug specimens, they looked specifically for geochemical signals of iron, which indicates blood meals. By combining those findings with results with morphological and taphonomic (fossilization) data, the team placed three of the bloodsuckers into two new genera within a new family, Torirostratidae.

The other fossilized true bugs belonged to phytophagous (plant eating) families or predaceous families, which include assassin bugs who would liquefy the insides of their prey, before drinking them. Their iron concentrations were much lower.

They named one of the new true bugs Flexicorpus acutirostratus. That’s Latin “flexi” for “soft” and “corpus” for “body.” The species name is taken from Latin “acuti” for “sharp” and “rostratus” for “beaked.” It's less than 10 millimeters long, and here are some cool pictures:

They’re naming the other one, which is over 12 millimeters long, Torirostratus pilosus. That’s Latin “torosus” for “bulges” and “rostratus” for “beaked” (again). The species name is comes from Latin “pilosus,” which refers to its dense setae (stiff bristles).

One of the bugs appears to have died immediately following a blood meal, which may have been taken from a mammal, bird, or dinosaur, though the researchers can’t be sure. (Insert Jurassic Park joke here, bonus points for True Blood.)

Images: Y. Yao et al., Current Biology 2014

Read more at http://www.iflscience.com/plants-and-animals/early-cretaceous-bloodsucking-bugs-found-china#mzQvUAVVY8ffihKI.99