Welcome to the Saturday Science Edition of Overnight News Digest
Overnight News Digest is a regular daily feature which provides noteworthy news items and commentary from around the world. The editorial staff includes side pocket, maggiejean, wader, Doctor RJ, rfall, and JML9999.
Neon Vincent is our editor-in-chief.
Special thanks go to Magnifico for starting this venerable series.
Astronomy
Spots On Pluto Fascinate As New Horizons Gets The All Clear
New color images from NASA’s New Horizons spacecraft show two very different faces of the mysterious dwarf planet, one with a series of intriguing spots along the equator that are evenly spaced. Each of the spots is about 300 miles (480 kilometers) in diameter, with a surface area that’s roughly the size of the state of Missouri. Scientists have yet to see anything quite like the dark spots; their presence has piqued the interest of the New Horizons science team due to the remarkable consistency in their spacing and size. While the origin of the spots is a mystery for now, the answer may be revealed as the spacecraft continues its approach to the mysterious dwarf planet. “It’s a real puzzle — we don’t know what the spots are, and we can’t wait to find out,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder. “Also puzzling is the longstanding and dramatic difference in the colors and appearance of Pluto compared to its darker and grayer moon Charon.” [...] After seven weeks of detailed searches for dust clouds, rings, and other potential hazards, the New Horizons team has decided the spacecraft will remain on its original path through the Pluto system instead of making a late course correction to detour around any hazards. Because New Horizons is traveling at 30,800 mph (49,600 kph), a particle as small as a grain of rice could be lethal.
“We’re breathing a collective sigh of relief knowing that the way appears to be clear,” said Jim Green, director of planetary science at NASA. “The science payoff will be richer as we gather data from the optimal flight path, as opposed to having to conduct observations from one of the backup trajectories.”
astronomy.com
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SOFIA Dashes Into Pluto’s Shadow
If you thought scientific data taking is a slow, boring process, you've never been on board SOFIA, the Stratospheric Observatory For Infrared Astronomy. On June 29th, SOFIA observed a stellar occultation by Pluto, and I was aboard to watch. It was the most exciting flight I've ever experienced. As many S&T.com readers know, SOFIA is basically an old Boeing 747-SP airliner that NASA bought and transformed into a flying infrared observatory. A German-built 2.5-meter telescope peers out into space through a large rectangular opening in the plane's fuselage. From the plane's typical cruising altitude (near 40,000 feet or 12 km), high above the clouds and most of the atmosphere's infrared-absorbing water vapor, the telescope can make unique infrared observations. [...] During the occultation Pluto casts a stellar shadow as wide as its diameter, about 2,300 km (1,430 miles). Observations from anywhere in the path would be scientifically useful, but everyone on board is very keen to hit the shadow path's centerline. When a distant star is exactly behind the center of a planet, a ring of refracted starlight produces a brief brightening in the light curve — a central flash. "We've learned what central-flash observations can tell you about atmospheric hazes," Dunham explains. Little wonder he's worried about whether SOFIA's new path will take his instrument to the right spot. [...] The brightness recording from the guiding camera is available almost instantly, and the star's light curve shows a very pronounced central flash. The plot also shows two very narrow dips: a shallower one some 2 minutes before the start of the occultation and a deeper one about a half minute after the event's end. "I don't think they are real," says Dunham, who's been chasing Pluto's shadow for three decades. "They're probably due to some instrumental effect. On the other hand: they could indicate that Pluto is surrounded by partial rings, just like Neptune." When the FLITECAM data become available, his intuition proves to be correct: the two dips don't show up. If Pluto has a ring system, it must be incredibly thin. skyandtelescope.com
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What Is A Terrestrial Planet?
In studying our Solar System over the course of many centuries, astronomers learned a great deal about the types of planets that exist in our universe. This knowledge has since expanded thanks to the discovery of extrasolar planets, many of which are similar to what we have observed here at home. For example, while hundreds of gas giants of varying size have been detected (which are easier to detect because of their size), numerous planets have also been spotted that are similar to Earth – aka. “Earth-like”. These are what is known as terrestrial planets, a designation which says a lot about a planet how it came to be. Definition: Also known as a telluric or rocky planet, a terrestrial planet is a celestial body that is composed primarily of silicate rocks or metals and has a solid surface. This distinguishes them from gas giants, which are primarily composed of gases like hydrogen and helium, water, and some heavier elements in various states. [...] Composition and Characteristics: All terrestrial planets have approximately the same type of structure: a central metallic core composed of mostly iron, with a surrounding silicate mantle. Such planets have common surface features, which include canyons, craters, mountains, volcanoes, and other similar structures, depending on the presence of water and tectonic activity. Terrestrial planets also have secondary atmospheres, which are generated through volcanism or comet impacts. This also differentiates them from gas giants, where the planetary atmospheres are primary and were captured directly from the original solar nebula. Terrestrial planets are also known for having few or no moons. Venus and Mercury have no moons, while Earth has only the one (the Moon). Mars has two satellites, Phobos and Deimos, but these are more akin to large asteroids than actual moons. Unlike the gas giants, terrestrial planets also have no planetary ring systems. universetoday.com
Biology
Below Our Feet, A World Of Hidden Life
Janet Jansson first started to wonder about the vast universe of underground life as a student at New Mexico State University in the late 1970s. A handful of soil contains about 10 billion bacteria, but at the time, earth scientists knew very little about what these microbes were and what they did. Later, as a young microbial ecologist at Stockholm University in Sweden, she started to catalog the microorganisms she collected during soil sampling trips, deciphering their genetic code so she could understand both their internal workings and how they fit into their underground habitat. As Jansson dug, though, she kept running into a problem. The main method then used to amplify and analyze stretches of DNA wasn’t powerful enough to reveal all the workings of a single microorganism, much less an entire community of them. “You could get information about specific genes, but sequencing technologies were very slow,” said Jansson, now a division director of biological sciences at Pacific Northwest National Laboratory (PNNL) in Richland, Wash. She knew the layers of sediment she studied held a treasure trove of biological finds, but she didn’t yet have the tools she needed to unearth them. Then, soon after the turn of the century, new high-octane DNA sequencing methods made it possible to sequence thousands or even millions of genes almost instantly. These new, speedier methods meant researchers could easily sequence the collective genomes of the sample, known as a metagenome, for the first time. Suddenly, it was possible to scan the overall composition of habitats as diverse as stagnant bogs and frozen tundra, producing a detailed portrait of the microbial life they held. The gene and protein sequences from these wide-ranging scans — the first of their kind — would, once decoded, illuminate what the microbes were actually doing within each ecosystem. The data would help researchers understand how microbes capture and store carbon dioxide from the atmosphere, how they break down organic matter so that plants can access its nutrients, and how they neutralize soil toxins known to threaten human health. “You can just sequence everything,” Jansson said. “That’s where the metagenomic approach has really been an advantage.” Almost everything about Jansson’s current surroundings is big and bold: the 600 acres of sycamore-studded PNNL campus rolling across eastern Washington, the endless blue sky she can see through her picture window, the fridge-size gene sequencing machine where her team deposits soil samples. But, as ever, what drives Jansson is the lure of the microscopic and the unseen — the challenge of mapping the contents of the soil microbiome, a teeming global community whose functions have never been fully understood. “Soil,” Jansson said, flashing a grin, “is the ultimate complex system.” quantamagazine.org
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Schizophrenia May Be The Price We Pay For A Big Brain
Plenty of us have known a dog on Prozac. We have also witnessed the eye rolls that come with the mention of canine psychiatry. Doting pet owners—myself included—ascribe all kinds of questionable psychological ills to our pawed companions. But in fact, the science suggests that numerous nonhuman species do suffer from psychiatric symptoms. Birds obsess; horses on occasion get pathologically compulsive; dolphins and whales, especially those in captivity, self-mutilate. And that thing when your dog woefully watches you pull out of the driveway from the window—that might be DSM-certified separation anxiety. “Every animal with a mind has the capacity to lose hold of it from time to time,” wrote science historian and author Laurel Braitman in her 2014 book Animal Madness. But at least one mental malady, while common in humans, seems to have spared other animals: schizophrenia, which affects an estimated 0.4 to 1 percent of adults. Although animal models of psychosis exist in laboratories, and odd behavior has been observed in creatures confined to cages, most experts agree that psychosis has not typically been seen in other species, whereas depression, obsessive-compulsive disorder and anxiety traits have been reported in many nonhuman species. This raises the question of why such a potentially devastating, often lethal disease is still hanging around plaguing humanity. We know from an abundance of recent research that schizophrenia is heavily genetic in origin. One would think that natural selection would have eliminated the genes that predispose to psychosis. A study published earlier this year in Molecular Biology and Evolution provides clues as to how the potential for schizophrenia may have arisen in the human brain and, in doing so, suggests possible treatment targets. It turns out that psychosis may be an unfortunate cost of having a big brain that is capable of complex cognition. scientificamerican.com
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Researchers Discover How Petunias Know When To Smell Good
Good timing is a matter of skill. You would certainly dress up for an afternoon business meeting, but not an evening session of binge-watching Netflix. If you were just a few hours off in your wardrobe timing, your spouse might wonder why you slipped into a stiff business suit to watch "House of Cards." While humans are alone in their struggle to balance work and Netflix, all creatures wrestle with proper timing. With limited resources, organisms are pressed to use time wisely in all aspects of their lives. As University of Washington researchers recently discovered, this struggle even extends to something as sweet and pleasant as the fragrant scent of a garden flower. A team of UW biologists has identified a key mechanism plants use to decide when to release their floral scents to attract pollinators. Their findings, published the week of June 29 in the Proceedings of the National Academy of Sciences, connect the production and release of these fragrant chemicals to the innate circadian rhythms that pulse through all life on Earth. [...]
"Plants emit these scents when they want to attract their pollinators," said Takato Imaizumi, UW associate professor of biology and senior author on the paper. "It makes sense that they should time this with when the pollinators will be around."
[...] Biologists have long recognized that creatures like plants, humans and even tiny bacteria all have circadian clocks -- genes that keep their cells synchronized to the 24-hour cycle of life on Earth. These genes regulate cellular activities based on the time of day. Researchers had previously shown that [the gene -- known by its acronym LHY] is a component of the circadian clock in other flowering plants, but this week's paper marks the first time biologists have connected LHY activity to flower scent. biologynews.net
Chemistry
Iron Found In Ancient Rock Is Recycled From Bacteria
Researchers in the US have shown that ancient bacteria may have played an essential role in creating iron deposits found in rock formations. This challenges the widely held view that the iron comes solely from vents in the Earth’s crust, and suggests that iron metabolism was an important part of early life on Earth. Banded iron formations (BIFs) are sedimentary rocks containing repeating layers of colourful iron oxides, which formed in the oceans between 4.6 billion and 540 million years ago. But quite how the iron got there in the first place has been a matter of debate. The most widely accepted model focuses on soluble Fe(II) spewed up from hydrothermal vents in the sea bed. It is supported by the isotopic composition of certain rare elements in BIFs, such as europium, that correspond to that of the hydrothermal fluid. However, this does not explain the large variation in isotopes of the iron itself, so some researchers have proposed that the iron may have been recycled by metabolic processes inside bacteria, and carried across land by rivers. ‘In the beginning, [my supervisor and I] had different views on how to interpret the iron isotope data,’ says Weiqiang Li, formerly of the University of Wisconsin-Madison. ‘I was always a little conservative and hesitant to say it was biological, because there were alternative explanations.’ To investigate further, Li and his colleagues decided to include neodymium isotopes, which vary with geological origin. The combined iron–neodymium data set provided two groups of correlating isotopes: one corresponding with hydrothermal systems and the other with continental rivers. ‘By introducing the mechanism of biology, the microbes recycling iron brought in by the [continental] rivers, we can essentially explain all the geochemical signatures that we observe. Before it was all a little awkward,’ says Li. rsc.org
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Airplane Coatings Help Recoup Fuel Efficiency Lost To Bug Splatter
When bugs explode against the wings of oncoming airplanes, they create a sticky problem for aerospace engineers. “A bug doesn’t know that it’s been catastrophically destroyed,” says Emilie J. (Mia) Siochi, a materials scientist with the National Aeronautics & Space Administration. “Its blood starts to thicken as if it’s healing any other injury.” This bug blood, or hemolymph, clings to an airplane’s wings, disrupting the smooth airflow over them and sapping the aircraft’s fuel efficiency. NASA scientists are now developing coatings that help aircraft shed or repel bug guts during flight. After screening nearly 200 different coating formulations, the NASA researchers recently flight-tested a handful of promising candidates on a Boeing ecoDemonstrator 757 aircraft in Shreveport, La. The team explored different combinations of polymer chemistry and surface structure and reports that it has created a coating that could reduce the amount of insect insides stuck to the wings by up to 40%. With further optimization, such coatings could allow planes to use 5% less fuel, Siochi says. Although that may not sound like much, it adds up. “That could be millions of dollars in fuel savings,” Siochi explains. The bump in fuel efficiency would also curb the amount of greenhouse gases emitted by planes, she says. cen.acs.org
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New Technology Using Silver May Hold Key To Electronics Advances
There may be broad applications in microelectronics, sensors, energy devices, low emissivity coatings and even transparent displays. [...] Silver has long been considered for the advantages it offers in electronic devices. Because of its conductive properties, it is efficient and also stays cool. But manufacturers have often needed high temperatures in the processes they use to make the devices, adding to their cost and complexity, and making them unsuitable for use on some substrates, such as plastics that might melt or papers that might burn. This advance may open the door to much wider use of silver and other conductors in electronics applications, researchers said.
"There's a great deal of interest in printed electronics, because they're fast, cheap, can be done in small volumes and changed easily," said Chih-hung Chang, a professor in the OSU College of Engineering. "But the heat needed for most applications of silver nanoparticles has limited their use." [...] "Because we could now use different substrates such as plastics, glass or even paper, these electronics could be flexible, very inexpensive and stable," Chang said. "This could be quite important and allow us to use silver in many more types of electronic applications."
sciencedaily.com
Earth Science
Extremely High Coastal Erosion In Northern Alaska
In a new study published today, scientists from the U.S. Geological Survey found that the remote northern Alaska coast has some of the highest shoreline erosion rates in the world.Analyzing over half a century of shoreline change data, scientists found the pattern is extremely variable with most of the coast retreating at rates of more than 1 meter a year. [...] Scientists studied more than 1600 kilometers of the Alaskan coast between the U.S. Canadian border and Icy Cape and found the average rate of shoreline change, taking into account beaches that are both eroding and expanding, was -1.4 meters per year. Of those beaches eroding, the most extreme case exceeded 18.6 meters per year. [...] Coastlines change in response to a variety of factors, including changes in the amount of available sediment, storm impacts, sea-level rise and human activities. How much a coast erodes or expands in any given location is due to some combination of these factors, which vary from place to place.
"There is increasing need for this kind of comprehensive assessment in all coastal environments to guide managed response to sea-level rise and storm impacts," said Dr. Bruce Richmond of the USGS. "It is very difficult to predict what may happen in the future without a solid understanding of what has happened in the past. Comprehensive regional studies such as this are an important tool to better understand coastal change."
enn.com
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Amazon’s Wildlife Threatened By Hydropower Dams, Study Says
As countries build more hydropower projects, new research warns that massive dams pose an extinction threat to mammals, birds and tortoises—at least in the Amazon. Brazil’s Balbina Dam has turned what was once undisturbed forest into an artificial archipelago of 3,546 islands where many vertebrates have disappeared, according to a study published Wednesday by England’s University of East Anglia. [...] The two-year study comes the same week that Brazil, in a joint U.S. announcement, pledged to restore 12 million hectares, or 46,332 square miles, of its forests—nearly the size of England—by 2030. It also promised to dramatically increase its use of solar, wind and geothermal energy. In fact, it’s planning to add floating solar panels to the Balbina Dam, located on the Uatuma River in the country’s northwestern rainforests. Brazil currently gets most of its electricity from hydropower and like other developing countries, it plans to build hundreds of new dams to meet rising energy demand. Hydropower, often touted as “green” because of its water reuse, produces more electricity worldwide than all other renewables combined. “Hydropower is an effective way, in many landscapes, to generate power,” says Peres. Yet its efficacy, he adds, depends on topography. In Brazil’s lowlands, a hydroelectric plant requires a large dam to raise the water level enough to create a cascade. In Colorado’s mountains, the rivers are on steeper slopes, so smaller reservoirs are needed. As a result, Peres says, a hydropower plant in flat areas produces a lot less electricity per flooded acre than one in the mountains. It also loses a lot more carbon-storing trees and other vegetation, so its environmental costs are higher. nationalgeoraphic.com
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Cuba’s Environmental Concerns Grow With Prospect of U.S. Presence
Like many of his countrymen, Jorge Angulo hopes the United States will lift the decades-old economic embargo against Cuba. But Dr. Angulo, a senior marine scientist at the University of Havana, is also worried about the effects that a flood of American tourists and American dollars might have on this country’s pristine coral reefs, mangrove forests, national parks and organic farms — environmental assets that are a source of pride here.
“Like anywhere else, money talks,” Dr. Angulo said. “That might be dangerous, because if we go too much on that side, we lose what we have today.”
As relations between the United States and Cuba have warmed — the countries announced on Wednesday that their embassies in Havana and Washington would reopen by July 20 for the first time in more than 50 years — and as the renewal of trade seems more of a possibility, the Cuban government faces pivotal choices. The country is in desperate need of the economic benefits that a lifting of the embargo would almost certainly bring. But the ban, combined with Cuba’s brand of controlled socialism, has also limited development and tourism that in other countries, including many of Cuba’s Caribbean neighbors, have eroded beaches, destroyed forests, polluted rivers, damaged coral reefs and wreaked other forms of environmental havoc. nytimes.com
Physics
The Cosmic Start Of Lightning
Even though lightning is a common phenomenon, the exact mechanism triggering a lightning discharge remains elusive. Scientists at the Dutch national research institute for mathematics CWI, the University of Groningen and the University of Brussels now published a realistic model involving large ice particles and cosmic rays. The big picture of lightning is clear: charge separation occurs inside a thundercloud and is eventually short-circuited by a conductive tube of ionized air. However, the electric field inside these clouds is usually an order of magnitude too low to create the conductive tube. This is why lightning inception is first out of the 'top ten questions in lightning research', according to a recent review. Lightning researchers at CWI (Amsterdam), the University of Groningen (KVI-CART), and the University of Brussels now claim to have cracked this question. Large ice particles or hydrometeors form the first ingredient of their model. These grow out of hailstones moving up and down in the turbulent air inside thunderclouds. When they grow in an elongated shape, this will focus the electric field inside the cloud on their tips. The increased electric field is high enough to accelerate free electrons and start an ionization cascade, necessary to create a conductive tube. [...] Normally there are too few free electrons present in the surrounding air to cause a discharge. However, these could be provided by high energy cosmic rays, which can generate large showers of free electrons. Computer simulations showed that in an electric field of 3 meters high and 0.2 km2, one air shower per minute of free electrons capable of discharge inception would occur. In short, free electrons from air showers caused by cosmic particles entering the atmosphere are accelerated in the electric field at the tip of a hydrometeor, and form self-propagating tubes of ionized air. These conductive tubes can short-circuit the built-up charge difference inside a thundercloud, between clouds or between a cloud and the earth's surface. The results, presented in a Physical Review Letters paper, show that this mechanism for discharge inception is realistic. phys.org
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Viewpoint: The Littlest Liquid
At the world’s most powerful particle accelerators, physicists collide high-energy heavy nuclei to create a soup of particles known as quark-gluon plasma (QGP). This state of matter doesn’t (as was initially expected) behave like a gas of quarks and gluons, but rather like a continuous liquid that, at four trillion degrees Celsius, is the hottest liquid ever created in the lab. So far, researchers have largely focused on plasma produced from collisions between large nuclei, such as gold and lead, each of which contains hundreds of protons and neutrons. Now, experiments from the Compact Muon Solenoid (CMS) Collaboration at CERN’s Large Hadron Collider provide new evidence that the liquidlike state can, unexpectedly, be created from a much smaller number of particles. The researchers studied collisions between a lead nucleus and a single proton and analyzed correlations between particles in the resulting plasma to provide evidence for liquid behavior. In addition to being the hottest and littlest liquid created in the lab, this state of matter is of interest because it carries the imprint of the two projectiles’ quantum states right before the collision. The liquid that forms from the collision of two heavy nuclei is an “emergent” state, meaning it exhibits properties that cannot be simply extrapolated from the behavior of a few particles. Rather, the plasma’s behavior is quantitatively and qualitatively different than its individual components (quarks and gluons). This behavior results from the strong interactions between particles and is characterized by collective effects, in which each particle’s motion is correlated with that of the others. Such emergent phenomena are common in macroscopic systems, such as superconductivity in metals. Unlike solids, however, which contain of order 1023 atoms, QGP consists of only a few hundred to a few thousand elementary particles. At CERN, a typical collision between two lead nuclei creates up to 25000 subatomic particles. In contrast, a collision between a proton and a lead nucleus may produce only 1000 particles because the proton impacts just a small volume of the lead nucleus. Researchers did not expect that a liquid would be created from such a small region of impact, and instead assumed that the resulting matter could be described in terms of elementary particle interactions. For this reason, preliminary evidence in 2013 that proton-lead collisions had produced a liquid triggered vivid discussions within the high-energy physics community. aps.org
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New Study Reveals How To Build Perfect Fire
“The adoption of fire in human civilization was a design change of the same nature as the emergence of organs for vision in animal design, the emergence of turbulence in laminar flow, the emergence of terrestrial animal locomotion from swimming, and the emergence of flying later on,” [Prof Adrian Bejan of Duke University] said. “This step occurred in an unmistakable direction, from no fire to fire, not the other way around. Why?” “The answer is the same for all the transitions: to facilitate movement and mixing on Earth. For us, fire means ultimately more movement for humanity on the landscape, in accord with the Constructal law.”
Almost two decades ago, in 1996, Prof Bejan penned the Constructal law that postulates that movement (flow) systems such as trees, rivers or air currents evolve into configurations that provide easier and easier access to flows. Now, the law is increasingly finding applications in improving design and maximizing efficiency of manmade systems. In his new study, Prof Bejan shows that the best campfires are roughly as tall as they are wide. The shape is the most efficient for the flow of air and heat.
“Our bonfires are shaped as cones and pyramids, as tall as they are wide at the base,” he said. “They look the same in all sizes, from the firewood in the chimney, to the tree logs and wooden benches in the center of the university campus after the big game. They look the same as the pile of charcoal we make to grill meat. And now we know why."
sci-news.com