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
Spacecraft Detects Aurora And Mysterious Dust Cloud Around Mars
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has observed two unexpected phenomena in the martian atmosphere: an unexplained high-altitude dust cloud and aurora that reaches deep into the martian atmosphere. [...] The cloud was detected by the spacecraft’s Langmuir Probe and Waves instrument and has been present the whole time MAVEN has been in operation. It is unknown if the cloud is a temporary phenomenon or something long lasting. The cloud density is greatest at lower altitudes. However, even in the densest areas it is still very thin. So far, no indication of its presence has been seen in observations from any of the other MAVEN instruments. Possible sources for the observed dust include dust wafted up from the atmosphere; dust coming from Phobos and Deimos, the two moons of Mars; dust moving in the solar wind away from the Sun; or debris orbiting the Sun from comets. However, no known process on Mars can explain the appearance of dust in the observed locations from any of these sources. MAVEN’s Imaging Ultraviolet Spectrograph observed what scientists have named “Christmas lights.” For five days just before Dec. 25, MAVEN saw a bright ultraviolet auroral glow spanning Mars’ northern hemisphere. Aurorae, known on Earth as northern or southern lights, are caused by energetic particles like electrons crashing down into the atmosphere and causing the gas to glow. “What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs — much deeper than on Earth or elsewhere on Mars,” said Arnaud Stiepen from the University of Colorado. “The electrons producing it must be really energetic.” astronomy
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New Dwarf Galaxies Near Milky Way
Two independent teams of astronomers went panning for gold in the Southern Hemisphere sky — and they struck it rich. Between the two, the teams discovered nine possible dwarf galaxies near the Milky Way, nuggets that may pave the way for a better understanding of dark matter in our local universe. The candidates are not yet confirmed dwarfs. Future observations will determine whether these are really dwarf galaxies or, the most likely alternative, crowded stellar cities known as globular clusters. [...] The dwarf candidates range in size from a mere 120 light-years to 1,300 light-years across. The nearest, Reticulum 2 at a distance of almost 100,000 light-years, is the strongest candidate. Even though it’s small (200 light-years across), it’s elongated, so it’s less likely to be a globular cluster posing as a dwarf galaxy. The second most-likely dwarf galaxy, Eridanus 2, is also stretched out and lies the farthest away at a whopping distance of 1.2 million light-years. [...]
“The only true confirmation that these objects are galaxies rather than globular clusters comes from measuring their total mass,” says Bechtol’s coauthor Alex Drlica-Wagner (Fermi National Accelerator Laboratory). “Unlike globular clusters, most of the mass of galaxies resides not in their stars but in the dark matter that surrounds them."
[...] The best way to measure the mass, Drlica-Wagner says, will be to collect spectra and measure the velocities of the stars with respect to one another. “For faint systems like those that we recently discovered, we will require some of the largest telescopes in the world to get accurate velocity measurements,” he adds. [...] The spectra will also tell astronomers about the bulk motions of the stars — that is, their collective motion either towards or away from the Milky Way — which will reveal whether these potential dwarfs are in fact satellites of our galaxy. skyandtelescope
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Public Asked To Help Name Features On Pluto
On July 14, NASA’s New Horizons spacecraft will fly past Pluto, offering the first close-up look at that small, distant world and its largest moon, Charon. These denizens of the outer solar system will be transformed from poorly seen, hazy bodies to tangible worlds with distinct features. Now, the public can help decide what labels will go on the images and maps coming from the flyby. The SETI Institute has announced the launch of its “Our Pluto” campaign, which is soliciting input on how to name features on the surfaces of Pluto and Charon. “Pluto belongs to everyone,” says New Horizon science team member Mark Showalter, a senior research scientist at the SETI Institute. “So we want everyone to be involved in making the map of this distant world.” The science team will not have time to come up with names during the quick flyby, so they must assemble a library of names in advance. Consequently, they are inviting the public to visit the web site http://www.ourpluto.org/ where they can vote for the names they think should be used to identify the most prominent features on both Pluto and Charon. They can also suggest additional names. These must be associated with a set of broad themes related to mythology and the literature and history of exploration. After the campaign ends on April 7, the New Horizons team will sort through the names and submit their recommendations to the International Astronomical Union (IAU). The IAU will decide how the names are used. seti
Biology
No Limit To Life In Deep Sediment Of Ocean's "Deadest" Region
"Who in his wildest dreams could have imagined that, beneath the crust of our Earth, there could exist a real ocean...a sea that has given shelter to species unknown?" So wrote Jules Verne almost 150 years ago in A Journey to the Center of the Earth. He was correct: Ocean deeps are anything but dead. Now, scientists have found oxygen and oxygen-breathing microbes all the way through the sediment from the seafloor to the igneous basement at seven sites in the South Pacific gyre, considered the "deadest" location in the ocean. [...]
"Our objective was to understand the microbial community and microbial habitability of sediment in the deadest part of the ocean," said scientist Steven D'Hondt of the University of Rhode Island Graduate School of Oceanography, lead author of the paper. "Our results overturn a 60-year-old conclusion that the depth limit to life is in the sediment just meters below the seafloor in such regions. "We found that there is no limit to life in this sediment. Oxygen and aerobic microbes hang in there all the way to the igneous basement, to at least 75 meters below the seafloor."
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New Study Explains Why Some Fungi Glow
According to a study co-led by Dr Cassius Stevani of the University of São Paulo and Prof Jay Dunlap of the Geisel School of Medicine at Dartmouth, the green light emitted from bioluminescent fungi attracts the attention of insects, including beetles, flies, wasps, and ants, which are apparently good for the fungi because the insects spread their spores. The study also shows that their bioluminescence is controlled by a temperature-compensated circadian clock. Bioluminescence is simply the ability of organisms to produce light on their own. Jellyfish and fireflies might be the most familiar bioluminescent creatures, but organisms from bacteria to fungi to insects and fish make their own glow through a variety of chemical processes. Glowing fungi have captured the imagination of cultures around the world. They have been well-known for centuries, from the bright orange and poisonous Jack-o-Lantern Mushroom (Omphalotus spp.) to the phenomenon known as ‘foxfire,’ where the nutrient-sipping threads of the Honey Mushroom (Armillaria spp.) give off a faint but eerie glow in rotten logs. Only 71 of more than 100,000 recognized species of fungi produce light in a biochemical process that requires oxygen and energy. [...] Prof Dunlap, Dr Stevani and their colleagues found that the Neonothopanus gardneri’s glow is under the control of a temperature-compensated circadian clock. They suggest that this level of control probably helps the fungi save energy by turning on the light only when it’s easy to see. sci-news
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Detailed Genetic Map Of World Wheat Varieties Developed
Kansas State University scientists have released findings of a complex, two-year study of the genomic diversity of wheat that creates an important foundation for future improvements in wheat around the world. Their work has produced the first haplotype map of wheat that provides detailed description of genetic differences in a worldwide sample of wheat lines. In genetics, a haplotype map is a powerful tool for transferring sequence-level variation to multiple gene mapping projects. "All of these new, genomic-based strategies of breeding promise to significantly accelerate breeding cycles and shorten release time of future wheat varieties," said Eduard Akhunov, associate professor of plant pathology and the project's leader. Plant scientists often look at the genetic makeup of an organism to breed new varieties for specific, desirable traits, such as drought, pest or disease resistance. Akhunov said the haplotype map gives scientists quick access to rich, genetic variation data that increases the precision of mapping genes in the wheat genome, and improves scientists' ability to select the best lines in breeding trials. sciencedaily
Chemistry
Mystery Of Coloured Water Droplets That Chase And Repel Each Other Solved
Researchers have solved the puzzle of a remarkable phenomenon that allows droplets of water mixed with a food colouring to move spontaneously and freely in intricate patterns when placed on a clean glass slide. The work could lead to novel applications, including autonomous sensing, fluidic machines and self-cleaning systems. The phenomenon was first noticed by researchers in Manu Prakash's lab at Stanford University, US, and it has captured their curiosity ever since. Three years and hundreds of experiments later they've now worked out why the droplets move and interact, allowing precise control over them. In one example, the team made different coloured droplets self-sort into their particular colour. They can also be made to repel or merge with other droplets.
YouTube Video
Controlling droplets precisely usually requires engineering complex patterns onto a surface. Without this, droplets fall foul of an effect known as contact line pinning – the reason why rain droplets stick to windows – which limits droplet movement. However, Prakash's team demonstrated that droplets could move freely on clean surfaces, including glass slides, unhindered by pinning. The researchers found that the reason comes down to the droplets being made from two miscible liquids – such as water and food colouring containing propylene glycol (PG). Experiments showed these binary fluid droplets don't stick and become pinned to surfaces thanks to the formation of a surface tension gradient between the water and the PG. This gradient occurs because water evaporates faster from the edge of the drop than the centre. This causes water to flow from the low surface tension area at the droplet’s edge to the high surface tension region in the centre, which almost totally suppresses pinning. As the droplets are not pinned, they can start to move around thanks to differences in the amount of vapour emitted by neighbouring droplets. They effectively ‘communicate’ with each other via mass transfer of water molecules from one drop to another, which creates an imbalance in the rate of evaporation, and thus surface tensions, on opposite sides of a single droplet. Such asymmetry provides the necessary force for drops to move towards each other, akin to how some cells and organisms move in response to chemical stimuli. rsc
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Figuring Out Fracking Wastewater
Almost 3 million gallons of concentrated salt water leaked in early January from a ruptured pipeline at a natural gas drilling site near Williston, N.D. The brine, a by-product of the oil and gas extraction method known as hydraulic fracturing, spilled into two creeks that empty into the Missouri River, according to news reports. Although a state health official said the salty water was quickly diluted once it reached the Missouri, the spill—large by North Dakota standards—raised questions about the contents of the brine. [...] For every well they drill, fracking operators pump 3 million to 5 million gal of water thousands of feet underground. There, the water opens fissures in the rock, allowing natural gas and oil to seep out of shale geologic formations. The water gets mixed with additives such as sand and surfactants to form fracking fluid, which is used to optimize the amount of fuel extracted But what goes down comes up. Shortly after the water gets injected, it flows back out of the well. The well releases water over its lifetime, larger volumes in the early stages and smaller quantities later on. The early-stage water—the so-called flowback—still contains many of the additives from the fracking fluid. As oil and gas production continues, water from the geologic formation mixes with the fracking fluid, bringing with it brine and other substances from underground. This “produced water” can be many times saltier than seawater—the salinity varies with the mineral content of the geologic formation. The flowback and produced water together make up fracking wastewater. [...] Even though these deep-well-injection and recycled-water holding ponds appear to contain the wastewater, as was the case in North Dakota, accidents happen. “The concern is, if there’s a spill or accident, it would be important to know what’s in the wastewater,” says Radisav D. Vidic, an environmental engineer at the University of Pittsburgh who studies wastewater treatment methods. Leaks could affect the water quality of nearby rivers, he adds. But figuring out the composition is no easy task. The fracking wastewater is a complex mixture of organics, metals, and radioactive materials. Some of these substances get put into the water as fracking fluid additives, some are formed during degradation or transformation reactions, and some come from the underground geologic formations. Many researchers are working to identify these components and their relative concentrations. chemical&engineeringnews
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Chemical Technique Dramatically Speeds Up 3-D Printing
With a trick of chemistry, researchers have sped up, and smoothed, the process of three-dimensional (3D) printing, producing objects in minutes instead of hours. 3D printers typically build one horizontal layer at time. Some do so by depositing droplets of building material as if they were laying tiny bricks. Others create their products by shining ultraviolet rays up into a bath of liquid resin. The light solidifies the resin, and the partial product is pulled upwards one notch to repeat the process for the next layer below. Objects appear to materialize out of the bath, just as the shape-shifting robot in the 1991 science-fiction film Terminator 2 formed out of liquid metal. But both types of processes can take several hours or even a day to produce a complex structure. A team led by Joseph DeSimone, a chemist at the University of North Carolina at Chapel Hill, has now refined the liquid-resin process to make it go continuously rather than in fits and starts. They made the bottom of the container that holds the resin bath from a material that is permeable to oxygen. Because oxygen inhibits the solidification of resin, it creates a ‘dead zone’—a layer just tens of microns thick at the bottom of the container—where the resin stays liquid even when ultraviolet rays are shining on it. The solidification reaction happens instead just above the dead zone. Because liquid is always present below the slowly forming object, the researchers can pull it up in a continuous manner, rather than waiting for new liquid resin to flow in. “When you operate this way you can go really fast,” says DeSimone. Depending on the object's size and the level of detail required, printing can take mere minutes. The faster process also makes it possible to use materials that were not suitable for traditional 3D printing methods, including some that are rubbery and flexible. [...] scientificamerican
Earth Science
The Importance Of Methane Seeps In Microbial Biodiversity Of Sea Floor
A new study “provides evidence that methane seeps are island-like habitats that harbor distinct microbial communities unique from other seafloor ecosystems." These seeps play an important role in microbial biodiversity of the sea floor. Methane seeps are natural gas leaks in the sea floor that emit methane into the water. Microorganisms that live on or near these seeps can use the methane as a food source, preventing the gas from collecting in the surrounding hydrosphere or migrating into the atmosphere. “Marine environments are a potentially huge source for methane outputs to the atmosphere, but the surrounding microbes keep things in check by eating 75 percent of the methane before it gets to the atmosphere. These organisms are an important part of the underwater ecosystem, particularly as it relates to global gas cycles that are climate important in terms of greenhouse gas emissions,” said University of Delaware assistant professor of marine biosciences, Jennifer Biddle. [...] In the study, Biddle and her international colleagues analyzed microbial samples from 23 methane seeps across the globe, and compared them to the microbial communities of 54 other seafloor ecosystems, including sulfate-methane transition zones, hydrothermal vents, coastal sediments and deep sea surface and subsurface sediments. While the researchers theorized that bacteria and archaea would vary by the amount of methane emitted by a given seep, what they found was that methane secretion wasn’t a determining factor; rather other energy sources from the surrounding environment were determined to have a greater role in determining what types of bacteria and microorganisms were present. environmentalnewsnetwork
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US Unveils New Rules To Govern Fracking On Federal Lands
The first major federal regulations on hydraulic fracking were released on Friday by the US Department of Interior. The rules, which apply to all fracking on land owned by the US government, are the first federal standards to regulate the process – by which a mix of chemicals and water are injected into the ground in order to drill for oil and natural gas. The regulations require companies to disclose the specific mix of chemicals they use while fracking, and allow government workers to inspect the safety of the concrete barriers around fracking wells. [...] The regulations will only cover a small percentage of natural gas and oil drilling operations in the United States – 11% of natural gas production and 5% of oil production occur on federal lands – but they set a model for states considering fracking regulation to follow. In a statement, interior secretary Sally Jewell said: “Current federal well-drilling regulations are more than 30 years old and they simply have not kept pace with the technical complexities of today’s hydraulic fracturing operations.” guardian
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21 Reasons Why Forests Are Important
March 21 is the International Day of Forests, a U.N. holiday highlighting the value of trees and the price of deforestation. In honor of this relatively new arboreal event, here are 21 reasons why forests matter. Forests cover a third of all land on Earth, providing vital organic infrastructure for some of the planet's densest, most diverse collections of life. They support countless species as well as 1.6 billion human livelihoods, yet humans are also responsible for 32 million acres of deforestation every year. The United Nations declared March 21 the International Day of Forests in late 2012, part of a global effort to publicize both the value and plight of woodlands around the world. It was first celebrated March 21, 2013, nestling in between the U.N.'s International Day of Happiness on March 20 and World Water Day March 22. (It's also near tree-centric Tu Bishvat in February and Arbor Day in April). Please click to see the list as a helpful reminder of what we all know. -Editor mothernaturenews
Physics
Explainer: What Are Fundamental Particles?
It is often claimed that the Ancient Greeks were the first to identify objects that have no size, yet are able to build up the world around us through their interactions. And as we are able to observe the world in tinier and tinier detail through microscopes of increasing power, it is natural to wonder what these objects are made of. We believe we have found some of these objects: subatomic particles, or fundamental particles, which having no size can have no substructure. We are now seeking to explain the properties of these particles and working to show how these can be used to explain the contents of the universe. There are two types of fundamental particles: matter particles, some of which combine to produce the world about us, and force particles – one of which, the photon, is responsible for electromagnetic radiation. These are classified in the standard model of particle physics, which theorises how the basic building blocks of matter interact, governed by fundamental forces. Matter particles are fermions while force particles are bosons. phys.org
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Diamond Bull's-Eye Collects Polarized Photons At A Rapid Rate
A new optical grating shaped like a "bull's-eye" that is extremely efficient at collecting photons from diamond nitrogen vacancy (NV) centres has been built by physicists in the US. The device can collect nearly three million photons per second from a single NV, which is the highest value reported to date. The grating could find use in a number of emerging technologies including nanoscale sensors, single-photon sources and quantum memories. Atomic impurities, or defects, in natural diamond lead to the pink, blue and yellow colours seen in some diamonds. One such defect, the nitrogen vacancy (NV) centre, occurs when two neighbouring carbon atoms in diamond are replaced by a nitrogen atom and an empty lattice site. [...] For anyone trying to build a quantum computer, NVs are useful because they have an electronic spin that is extremely well isolated from the surrounding lattice – so if an NV is placed in a certain spin state, then it will remain in that state for a long time, even at room temperature. What is more, an NV's electron spin can be entangled with the polarization state of a photon, and such spin–photon entanglement might help in the development of quantum networks and distributed quantum computers of the future. NVs in nanoscale diamonds could also be used as biological probes and sensors because they are non-toxic, stable and can easily be inserted into living cells. They are also capable of detecting the very weak magnetic fields that come from surrounding electronic or nuclear spins. This means that they can be used as highly sensitive magnetic-resonance probes capable of monitoring local spin changes in a target material across distances of just tens of nanometres physicsworld
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The World's Biggest Physics Experiment Is About To Reboot
The Large Hadron Collider (LHC) is the most audacious physics experiment in human history. Now scientists are about to restart the giant particle collider for a new set of experiments. Last time, they did the almost-impossible and found the Higgs Boson. This time, they might find something even more exciting. Back in 2008, just nine days into its first run of experiments, there was a significant incident at the Large Hadron Collider. A faulty electrical connection between two magnets stopped superconducting, then melted and caused serious mechanical damage to the facility. The accident delayed use of the LHC for six whole months as repairs and testing was undertaken—but it also meant that the facility ran for three years at much lower capacity than envisioned. Clearly the collider coped. On July 4th 2012, scientists from two experiments at the LHC—CMS and ATLAS—announced that they had discovered a new boson. It was the Higgs Boson; the invisible particle that gives everything mass and, in turn, holds the universe together. The finding was arguably the biggest scientific finding of the decade, perhaps even more. But all the while it was running below par. The LHC shut down for maintenance in 2013, though, and over the past two years, engineers have beefed it up. They've upgraded the superconducting interconnections between a series of magnets on the accelerator, adding extra shunts and more powerful magnets. The shunts provide a route through which current can escape if high-power accidents—like the one that caused the break back in 2008—happen again, meaning it's safer to run at higher energy levels. [...] Sadly, it's not possible to simply flick a switch on the LHC and summon 13TeV on demand. Instead, the $6 billion accelerator requires a gradual warm up before it reaches peak power. Last week, CERN researchers sent the first test particles through the accelerator. Slowly, over the coming weeks, they'll send more and more, each time checking the alignment of the beams and the accelerator's ability handle them. Cern's director general, Rolf-Dieter Heuer, has said that the LHC will be loaded with the first proper proton beams in the next two weeks. The accelerator should gradually ramp up to higher energies, with the resulting collisions—which will be the most energetic ever created by humans—due to follow near the end of May. gizmodo