Artist’s conception of a red giant star engulfing one of its planets (credit: NASA)
The first evidence of a planet’s destruction by its aging star has been discovered by an international team of astronomers. The evidence indicates that the missing planet was devoured as the star began expanding into a red giant—the stellar equivalent of advanced age for stars without enough mass to go supernova.
“A similar fate may await the inner planets in our solar system, when the Sun becomes a red giant and expands all the way out to Earth’s orbit some five-billion years from now,” said Alex Wolszczan, an Evan Pugh Professor of Astronomy and Astrophysics at Penn State, University, who is one of the members of the research team. Wolszczan also is the discoverer of the first planet ever found outside our solar system. The astronomers also discovered a massive planet in a surprisingly elliptical orbit around the same red-giant star, named BD+48 740, which is older than the Sun with a radius about eleven times bigger. Wolszczan and the team’s other members, Monika Adamow, Grzegorz Nowak, and Andrzej Niedzielski of Nicolaus Copernicus University in Torun, Poland; and Eva Villaver of the Universidad Autonoma de Madrid in Spain, detected evidence of the missing planet’s destruction while they were using the Hobby-Eberly Telescope to study the aging star and to search for planets around it. The evidence includes the star’s peculiar chemical composition plus the highly unusual elliptical orbit of its surviving planet. Read more ..
Artist’s conception of the PTF 11kx system (credit: Romano Corradi/Instituto de Astrofísica de Canarias)
Type 1a supernovae—exploding stars—are ideal for measuring cosmic distance because they are bright enough to spot across the Universe and have relatively the same luminosity everywhere. Although astronomers have many theories about the kinds of star systems involved in these explosions (or progenitor systems), no one has ever directly observed one—until now.
In the August 24 issue of Science, the multi-institutional Palomar Transient Factory (PTF) team presents the first-ever direct observations of a Type 1a supernova progenitor system. Astronomers have collected evidence indicating that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much smaller nova eruption before it ended its life in a destructive supernova. The system is located 600 million light years away in the constellation Lynx.
By comparison, indirect observations of another Type 1a supernova progenitor system (called SN 2011fe, conducted by the PTF team last year) showed no evidence of a red giant star. Taken together, these observations unequivocally show that just because Type 1a supernovae look the same, that doesn’t mean they are all born the same way. Read more ..
New research led by University of Warwick physicist Dr Kareem Osman has provided significant insight into how the solar wind heats up when it should not. The solar wind rushes outwards from the raging inferno that is our Sun, but from then on the wind should only get cooler as it expands beyond our solar system since there are no particle collisions to dissipate energy. However, the solar wind is surprisingly hotter than it should be, which has puzzled scientists for decades. Two new research papers led by Dr Osman may have solved that puzzle.
Turbulence pervades the universe, being found in stars, stellar winds, accretion disks, galaxies, and even the material between galaxies. It also plays a critical role in the evolution of many laboratory plasmas, causing diminished confinement times in fusion devices. Therefore, understanding plasma turbulence is essential to the interpretation of a large body of laboratory, space, and astrophysical observations. The solar wind and near-Earth environment provide an excellent laboratory for the study of turbulence, and are the only in-situ accessible astrophysical plasmas. Read more ..
In India, the government is defending itself against charges of Internet censorship after asking companies such as Facebook and Twitter to block hundreds of websites. India's efforts to regulate online content and pressure social media companies have attracted criticism.
Following threats to take action against Twitter, Indian officials say the micro-blogging site has agreed to talk to the government. But the government’s face-off with Twitter is far from over.
The government wants Twitter to remove 28 pages containing what it calls “objectionable content,” but officials say Twitter has cited technical difficulties in complying with the request. The government asked social networking sites such as Facebook and Twitter to block hundreds of websites and pages recently after doctored online images fueled rumors of revenge attacks by Muslims on migrants from the north east, prompting them to flee cities. Communication and Information Technology Minister Kapil Sibal refutes charges that the government is trying to censor social media. But he says its misuse has to be prevented.
We know that stars group together to form galaxies, galaxies clump to make clusters and clusters gather to create structures known as superclusters. At what scale though, if at all, does this Russian doll-like structure stop? Scientists have been debating this very question for decades because clustering on large scales would be in conflict with our 'standard model' of cosmology. The current model is based on Einstein's equations assuming everything is smooth on the largest scales. If matter were instead clumpy on very large scales, then the entire model would need to be rethought.
Cosmologists agree that on 'small' scales (tens of millions of light years), matter in the Universe is highly clustered. So the 'standard model' can only hold true if the Universe transitions to an even distribution of matter (homogeneity) on larger scales, irrespective of the viewing direction. However, some scientists have recently argued that the entire Universe never becomes homogenous, and that it is clustered on all scales, much like one of Mandelbrot's famous 'fractals' (a snowflake is a good example of a fractal). If the Universe has properties similar to a fractal, our description of space and time is wrong, and our understanding of things like Dark Energy is deeply flawed.
A penny-sized rocket thruster may soon power the smallest satellites in space. The device, designed by Paulo Lozano, an associate professor of aeronautics and astronautics at MIT, bears little resemblance to today’s bulky satellite engines, which are laden with valves, pipes and heavy propellant tanks. Instead, Lozano’s design is a flat, compact square — much like a computer chip — covered with 500 microscopic tips that, when stimulated with voltage, emit tiny beams of ions. Together, the array of spiky tips creates a small puff of charged particles that can help propel a shoebox-sized satellite forward. “They’re so small that you can put several [thrusters] on a vehicle,” Lozano says. He adds that a small satellite outfitted with several microthrusters could “not only move to change its orbit, but do other interesting things — like turn and roll.” Lozano and his group in MIT’s Space Propulsion Laboratory and Microsystems Technology Laboratory presented their new thruster array at the American Institute of Aeronautics and Astronautics’ recent Joint Propulsion Conference.
Cleaning up CubeSat clutter Today, more than two dozen small satellites, called CubeSats, orbit Earth. Each is slightly bigger than a Rubik’s cube, and weighs less than three pounds. Their diminutive size classifies them as “nanosatellites,” in contrast with traditional Earth-monitoring behemoths. These petite satellites are cheap to assemble, and can be launched into space relatively easily: Since they weigh very little, a rocket can carry several CubeSats as secondary payload without needing extra fuel. Read more ..
Northwestern University scientists have connected 250 years of organic chemical knowledge into one giant computer network -- a chemical Google on steroids. This "immortal chemist" will never retire and take away its knowledge but instead will continue to learn, grow and share.
A decade in the making, the software optimizes syntheses of drug molecules and other important compounds, combines long (and expensive) syntheses of compounds into shorter and more economical routes and identifies suspicious chemical recipes that could lead to chemical weapons.
"I realized that if we could link all the known chemical compounds and reactions between them into one giant network, we could create not only a new repository of chemical methods but an entirely new knowledge platform where each chemical reaction ever performed and each compound ever made would give rise to a collective 'chemical brain,'" said Bartosz A. Grzybowski, who led the work. "The brain then could be searched and analyzed with algorithms akin to those used in Google or telecom networks." Read more ..
Fierce galactic winds powered by an intense burst of star formation may blow gas right out of massive galaxies, shutting down their ability to make new stars.
Sifting through images and data from three telescopes, a team of astronomers found 29 objects with outflowing winds measuring up to 2,500 kilometers per second, an order of magnitude faster than most observed galactic winds.
"They're nearly blowing themselves apart," said Aleksandar Diamond-Stanic, a fellow at the University of California's Southern California Center for Galaxy Evolution, who led the study. "Most galactic winds are more like fountains; the outflowing gas will fall back onto the galaxies. With the high-velocity winds we've observed the outflowing gas will escape the galaxy and never return." The galaxies they observed are a few billion light years away with outflowing winds of 500 to 2,500 kilometers per second. Initially they thought the winds might be coming from quasars, but a closer look revealed these winds emanate from entire galaxies. Young, bright and compact, these massive galaxies are in the midst of or just completing a period of star formation as intense as anyone has ever observed. Read more ..
A humble soil bacterium called Ralstonia eutropha has a natural tendency, whenever it is stressed, to stop growing and put all its energy into making complex carbon compounds. Now scientists at MIT have taught this microbe a new trick: They've tinkered with its genes to persuade it to make fuel — specifically, a kind of alcohol called isobutanol that can be directly substituted for, or blended with, gasoline.
Christopher Brigham, a research scientist in MIT's biology department who has been working to develop this bioengineered bacterium, is currently trying to get the organism to use a stream of carbon dioxide as its source of carbon, so that it could be used to make fuel out of emissions. Brigham is co-author of a paper on this research published this month in the journal Applied Microbiology and Biotechnology.
Brigham explains that in its natural state, when the microbe's source of essential nutrients (such as nitrate or phosphate) is restricted, "it will go into carbon-storage mode," essentially storing away food for later use when it senses that resources are limited. Read more ..
Warming causes more extreme shifts of the Southern Hemisphere's largest rain band
South Pacific countries will experience more extreme floods and droughts, in response to increasing greenhouse gas emissions, according to a paper out today in the journal Nature.
The changes will result from the South Pacific rain band responding to greenhouse warming. The South Pacific rain band is largest and most persistent of the Southern Hemisphere spanning the Pacific from south of the Equator, south-eastward to French Polynesia. Occasionally, the rain band moves northwards towards the Equator by 1000 kilometres, inducing extreme climate events.
The international study, led by CSIRO oceanographer Dr Wenju Cai, focuses on how the frequency of such movement may change in the future. The study finds the frequency will almost double in the next 100 years, with a corresponding intensification of the rain band. Read more ..
An ancient skull recovered from a cave in the Annamite Mountains in northern Laos is the oldest modern human fossil found in Southeast Asia, researchers report. The discovery pushes back the clock on modern human migration through the region by as much as 20,000 years and indicates that ancient wanderers out of Africa left the coast and inhabited diverse habitats much earlier than previously appreciated.
The team described its finding in a paper in Proceedings of the National Academy of Sciences. The scientists, who found the skull in 2009, were likely the first to dig for ancient bones in Laos since the early 1900s, when a team found skulls and skeletons of several modern humans in another cave in the Annamite Mountains. Those fossils were about 16,000 years old, much younger than the newly found skull, which dates to between 46,000 and 63,000 years old.
"It's a particularly old modern human fossil and it's also a particularly old modern human for that region," said University of Illinois anthropologist Laura Shackelford, who led the study with anthropologist Fabrice Demeter, of the National Museum of Natural History in Paris. "There are other modern human fossils in China or in Island Southeast Asia that may be around the same age but they either are not well dated or they do not show definitively modern human features. This skull is very well dated and shows very conclusive modern human features," she said. Read more ..
Melting over the Greenland ice sheet shattered the seasonal record on August 8 – a full four weeks before the close of the melting season, reports Marco Tedesco, assistant professor of Earth and atmospheric sciences at The City College of New York.
The melting season in Greenland usually lasts from June – when the first puddles of meltwater appear – to early-September, when temperatures cool. This year, cumulative melting in the first week in August had already exceeded the record of 2010, taken over a full season, according to Professor Tedesco's ongoing analysis. "With more yet to come in August, this year's overall melting will fall way above the old records. That's a goliath year – the greatest melt since satellite recording began in 1979," said Professor Tedesco. This spells a change for the face of southern Greenland, he added, with the ice sheet thinning at its edges and lakes on top of glaciers proliferating. Read more ..
By now it's old news that NASA's new Mars rover Curiosity is resting safely on the surface of Red Planet after a daredevil landing that had the nation holding its breath. Now, mission scientists are anxious to start moving. With such a sweet set of wheels at their disposal and the "open road" before them, just where will they go first?
"We won't have to travel far for excitement," says project scientist John Grotzinger. "We landed in the best possible place within the landing ellipse -- the bottom of an alluvial fan." An alluvial fan is a pattern of sedimentary rocks, dirt, and sand deposited by flowing water – in this case, perhaps an ancient Martian river. Since life as we know it requires liquid water, this is an excellent first place to search for clues of a Mars that was once hospitable to life.
"The alluvial fan indicates that water flowed across the surface, so we'll head downhill to where water might have collected. We'll be looking for minerals like salts that might tell us where water has been. It's kind of like a scavenger hunt with minerals as clues." Read more ..
Earthworms could be used to extract toxic heavy metals, including cadmium and lead, from solid waste from domestic refuse collection and waste from vegetable and flower markets, according to researchers writing in the International Journal of Environment and Waste Management.
Swati Pattnaik and M. Vikram Reddy of the Department of Ecology and Environmental Sciences, at Pondicherry University, in Puducherry, India, explain how three species of earthworm, Eudrilus eugeniae, Eisenia fetida and Perionyx excavates can be used to assist in the composting of urban waste and to extract heavy metals, cadmium, copper, lead, manganese, zinc, prior to subsequent processing.
With rapid increases in urban populations particularly in the developing world, there is a growing problem of how to manage organic waste and to find alternatives to landfill disposal particularly for domestic food waste and that from vegetable markets. According to the research team, it is an unfortunate fact of life that much of this waste is currently dumped on the outskirts of many towns and cities and is causing serious pollution, disease risk and general ecological harm. It also represents a considerable wasted resource, whereas the organic matter might be exploited usefully in growing food crops. Read more ..
Certain bacteria in the human gut seem to be associated with pre-diabetes, a condition marked by a constellation of risk factors that often precedes the on-set of full-blown type 2 diabetes in humans. The finding is part of an effort to discover the role of trillions of bacteria or microbiota that live in our bodies.
According to Brandi Cantarel, the number of bacteria living happily inside us outnumbers human cells by an astounding 10-1. Cantarel is a researcher at the Institute for Genome Science at the University of Maryland School of Medicine in Baltimore. “With all that extra stuff, let’s say genetic material in our bodies that doesn’t come from us, it comes from other sources, we think it has to be doing something," said Cantarel. "Right?”
According to Cantarel, scientists believe there are over 7,000 strains of more than 1,000 different species of bacteria that live in the digestive tract, most of them in the gut or small intestine, which play a role in human health. Many of the trillions of microbes are helpful; without them, for example, we couldn’t digest food properly. But experts say bacteria that are out of balance could be harmful. Researchers have identified 26 microbes that researchers say may be negatively associated with pre-diabetes or metabolic syndrome. Read more ..
As mobile speech recognition technologies continue to improve in their efficacy, the vendors of the speech technology platforms are making concerted efforts to enable the long tail of mobile application developers with speech recognition capabilities.
ABI Research notes the efforts of companies such as Nuance, AT&T, and iSpeech for exposing their APIs and developer programs as the foremost strategy in reaching the long tail of mobile applications. “Reaching a varied group of developers working on different OS and hardware platforms makes cloud based solutions the optimum approach to enabling the masses,” says mobile devices, content and applications senior analyst Michael Morgan. “It is the approach of using network based solutions that will drive the rapid increase in cloud based revenues.”
Historically, mobile speech recognition was delivered to consumers through relationships between device OEMs and platform vendors. The other route to the consumer came through virtual assistant applications that were often developed by the platform vendors. Read more ..
Researchers in Korea have developed a low cost technique to print antennas that can be used to deliver power wirelessly.
The rectenna design couples with an AC field to provide a DC output to power devices such as sensors. The design, by researchers at the Printed Electronics Engineering programme of Sunchon National University and the Paru Printed Electronics Research Institute in Sunchon, can even harvest the energy radiated by mobile phones to power devices. This could allow sensor networks such as RFID tags, price tags, smart logos, signage, and sensors could be fully interconnected and driven by DC power of less than 0.3 W.
“What is great about this technique is that we can also print the digital information onto the rectenna, meaning that everything you need for wireless communication is in one place,” said Gyoujin Cho, co-author of the study. “Our advantage over current technology is lower cost, since we can produce a roll-to-roll printing process with high throughput in an environmentally friendly manner. Furthermore, we can integrate many extra functions without huge extra cost in the printing process.” Read more ..
In an age of increasingly uncertain weather, a new Israeli meteorological innovation may become the most powerful way of predicting the weather yet. Shipping companies, aviation specialists, sailors, farmers, wind turbine owners – — even the Boy Scouts – know that better weather prediction leads to a better ability to avoid risks to infrastructure, products and lives.
This is especially true when faced with today’s increasingly unpredictable weather. Professionals with a lot at stake can’t rely on a weatherman’s forecast, which can change like the wind. Meteo-Logic, a new cutting-edge meteorological innovation from Israel, can deliver real-time updates on the weather in what some experts believe is the most powerful way of predicting the weather yet. “Generally there are two or three concepts you need to look at in order to accurately predict the weather,” said Igal Zivoni, founder and CEO of Meteo-Logic. Read more ..
American bullfrog devours native frog in Brazil. Credit: Julia Toledo
The global trade in bullfrogs, which are farmed as a food source in South America and elsewhere, is spreading a deadly fungus that is contributing to the decline of amphibians worldwide, according to a University of Michigan biologist and his colleagues. Amphibian populations are declining worldwide at an alarming rate, and the spread of the deadly chytrid fungus is believed to be a contributing factor. The fungus infects the skin of frogs, toads and salamanders.
University of Michigan evolutionary biologist Timothy James and his colleagues examine the role of bullfrog farming in spreading the chytrid fungus between the forests and frog farms of Brazil and then to the United States and Japan. The researchers collected and analyzed bullfrogs sold at Asian food shops in seven U.S. cities and found that 41 percent of the frogs were infected with chytrid fungus, which is harmless to humans. Frogs in these shops are imported live primarily from farms in Taiwan, Brazil and Ecuador and sold as food for their legs. James and his colleagues also analyzed bullfrogs from frog farms in Brazil and several native frog species from Brazil's Atlantic Forest, one of the most amphibian-rich regions in the world. Their DNA sequencing studies identified the various strains of the chytrid fungus, Batrachochytrium dendrobatidis or Bd for short, present in the frogs. Read more ..
Geckos are remarkable little creatures, clinging to almost any dry surface, and Alyssa Stark, from the University of Akron, USA, explains that they appear to be equally happy scampering through tropical rainforest canopies as they are in urban settings. “A lot of work is done on geckos that looks at the very small adhesive structures on their toes to really understand how the system works at the most basic level,” says Stark. She adds that the animals grip surfaces with microscopic hairs on the soles of their feet that make close enough contact to be attracted to the surface by the minute van der Waals forces between atoms. However, she and her colleagues Timothy Sullivan and Peter Niewiarowski were curious about how the lizards cope on surfaces in their natural habitat.
Explaining that previous studies had focused on the reptiles clinging to artificial dry surfaces, Stark says “We know they are in tropical environments that probably have a lot of rain and it’s not like the geckos fall out of the trees when it’s wet.” Yet, the animals do seem to have trouble getting a grip on smooth wet surfaces, sliding down wet vertical glass after a several steps even though minute patches of the animals’ adhesive structures do not slip under humid conditions on moist glass. The team decided to find out how Tokay geckos with wet feet cope on wet and dry surfaces, and publish their discovery that geckos struggle to remain attached as their feet get wetter in the Journal of Experimental Biology. Read more ..
Solar eruption with coronal mass ejection (credit: NASA)
Stormy weather on the sun could soon wreak havoc on Earth, knocking the world’s power grids off line while damaging communication equipment, satellites, spacecraft and GPS systems, possibly leaving us unable to communicate or transact normal business.
Mike Hapgood, a scientist who specializes in space weather at the Rutherford Appleton Laboratory in England, told Reuters governments around the world are taking threats posed by these solar storms so seriously that they’re putting them on their national risk registers, which are normally used for disaster planning, along with events like tsunamis and volcanic eruption. “These things may be very rare but when they happen, the consequences can be catastrophic,” Hapgood said.
The sun, just like Earth, has its own weather systems. And, just like on Earth, the sun can have bouts of really stormy conditions from time to time. Read more ..
Major depression or chronic stress can cause the loss of brain volume, a condition that contributes to both emotional and cognitive impairment. Now a team of researchers led by Yale scientists has discovered one reason why this occurs — a single genetic switch that triggers loss of brain connections in humans and depression in animal models.
The findings, reported in the Aug. 12 issue of the journal Nature Medicine, show that the genetic switch known as a transcription factor represses the expression of several genes that are necessary for the formation of synaptic connections between brain cells, which in turn could contribute to loss of brain mass in the prefrontal cortex.
"We wanted to test the idea that stress causes a loss of brain synapses in humans," said senior author Ronald Duman, the Elizabeth Mears and House Jameson Professor of Psychiatry and professor of neurobiology and of pharmacology. "We show that circuits normally involved in emotion, as well as cognition, are disrupted when this single transcription factor is activated."
The research team analyzed tissue of depressed and non-depressed patients donated from a brain bank and looked for different patterns of gene activation. The brains of patients who had been depressed exhibited lower levels of expression in genes that are required for the function and structure of brain synapses. Lead author and postdoctoral researcher H.J. Kang discovered that at least five of these genes could be regulated by a single transcription factor called GATA1. When the transcription factor was activated, rodents exhibited depressive-like symptoms, suggesting GATA1 plays a role not only in the loss of connections between neurons but also in symptoms of depression. Read more ..
Why, after millions of years of evolution, do organisms build structures that seem to serve no purpose?
A study conducted at Michigan State University and published in the current issue of The American Naturalist investigates the evolutionary reasons why organisms go through developmental stages that appear unnecessary.
“Many animals build tissues and structures they don’t appear to use, and then they disappear,” said Jeff Clune, lead author and former doctoral student at MSU’s BEACON Center of Evolution in Action. “It’s comparable to building a roller coaster, razing it and building a skyscraper on the same ground. Why not just skip ahead to building the skyscraper?”
Why humans and other organisms retain seemingly unnecessary stages in their development has been debated between biologists since 1866. This study explains that organisms jump through these extra hoops to avoid disrupting a developmental process that works. Clune’s team called this concept the “developmental disruption force.” But Clune says it also could be described as “if the shoe fits, don’t change a thing.”
“In a developing embryo, each new structure is built in a delicate environment that consists of everything that has already developed,” said Clune, who is now a postdoctoral fellow at Cornell University. “Mutations that alter that environment, such as by eliminating a structure, can thus disrupt later stages of development. Even if a structure is not actually used, it may set the stage for other functional tissues to grow properly.”
Going back to the roller coaster metaphor, even though the roller coaster gets torn down, the organism needs the parts from that teardown to build the skyscraper, he added.
“An engineer would simply skip the roller coaster step, but evolution is more of a tinkerer and less of an engineer,” Clune said. “It uses whatever parts that are lying around, even if the process that generates those parts is inefficient.”
An interesting consequence is that newly evolved traits tend to get added at the end of development, because there is less risk of disrupting anything important. That, in turn, means that there is a similarity between the order things evolve and the order they develop. Read more ..
For years, many scientists had thought that plate tectonics existed nowhere in our solar system but on Earth. Now, a UCLA scientist has discovered that the geological phenomenon, which involves the movement of huge crustal plates beneath a planet’s surface, also exists on Mars.
“Mars is at a primitive stage of plate tectonics. It gives us a glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth,” said An Yin, a UCLA professor of Earth and space sciences and the sole author of the new research.
Yin made the discovery during his analysis of satellite images from NASA’s THEMIS spacecraft and from the HIRISE camera on NASA’s Mars Reconnaissance Orbiter. He analyzed about 100 satellite images—and approximately a dozen were revealing of plate tectonics. Yin has conducted geologic research in the Himalayas and Tibet, where two of the Earth’s seven major plates divide. “When I studied the satellite images from Mars, many of the features looked very much like fault systems I have seen in the Himalayas and Tibet, and in California as well, including the geomorphology,” said Yin, a planetary geologist. Read more ..
By the end of 2012, almost 20% of annual smartphone shipments will include facial recognition capabilities, according to new data from ABI Research. In five years' time, shipments of smartphones and tablets with the technology will increase to 665 million annually. Currently, only Google’s Ice Cream Sandwich and Jelly Bean mobile operating systems support the technology in significant volumes. The Samsung Galaxy SIII is one of the most notable smartphones to feature this technology. Over the next two to three years, many more operating systems and mobile OEMs will incorporate the technology.
Facial recognition has been on the technology radar for some time. It was developed in the 1960s by three scientists: Woody Bledsoe, Helen Chan Wolf, and Charles Bisson. Historically, the major challenge for the technology in mobile devices has been incorporating an accurate enough sensor (camera) and a powerful enough processor to undertake the complex algorithms while limiting power consumption. Thanks to major technology advancements, this has changed, notes ABI Research. “Facial recognition technology has improved drastically over the last 10 years and accuracy is almost always above 90%,” says ABI Research senior analyst Josh Flood. “That said, lighting conditions and facial expressions can sometimes cause problems with the recognition. However, the improvements in camera resolution and processing power utilized by mobile devices has helped greatly.” Read more ..
Artist’s conception of Swift J1644+57 (credit: NASA GSFC)
Last year, astronomers discovered a quiescent black hole in a distant galaxy that erupted after shredding and consuming a passing star. Now researchers have identified a distinctive X-ray signal observed in the days following the outburst that comes from matter on the verge of falling into the black hole. This tell-tale signal, called a quasi-periodic oscillation (QPO), is a characteristic feature of the accretion disks that often surround the most compact objects in the universe—white dwarf stars, neutron stars and black holes. QPOs have been seen in many stellar-mass black holes, and there is tantalizing evidence for them in a few black holes that may have middleweight masses between 100 and 100,000 times the sun’s.
Until the new finding, QPOs had been detected around only one supermassive black hole—the type containing millions of solar masses and located at the centers of galaxies. That object is the Seyfert-type galaxy REJ 1034+396, which at a distance of 576 million light-years lies relatively nearby. Read more ..
Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have combined the power of two kinds of microscope to produce a 3-dimensional movie of how cells “swallow” nutrients and other molecules by engulfing them. The study, published in Cell, is the first to follow changes in the shape of the cell’s membrane and track proteins thought to influence those changes. It also provides ample data to investigate this essential process further.
This “swallowing,” called endocytosis, is involved in a variety of crucial tasks. It is used by brain cells relaying information to each other, for instance, and is also hijacked by many viruses, which use it to invade their host’s cells. When a cell is about to swallow some molecules, a dent appears in the cell’s membrane, and gradually expands inwards, pinching off to form a little pouch, or vesicle, that transports molecules into the cell. Read more ..
The galaxy NGC 1187, discovered is seen almost face-on, which gives us a good view of its spiral structure. About half a dozen prominent spiral arms can be seen, each containing large amounts of gas and dust. The bluish features in the spiral arms indicate the presence of young stars born out of clouds of interstellar gas. Looking towards the central regions, we see the bulge of the galaxy glowing yellow. This part of the galaxy is mostly made up of old stars, gas, and dust. In the case of NGC 1187, rather than a round bulge, there is a subtle central bar structure. Such bar features are thought to act as mechanisms that channel gas from the spiral arms to the centre, enhancing star formation there.
Around the outside of the galaxy many much fainter and more distant galaxies can also be seen. Some even shine right through the disc of NGC 1187 itself. Their mostly reddish hues contrast with the pale blue star clusters of the much closer object. Read more ..
Artist’s conception of sunrise on CoRoT-71b (credit: ESO/L. Calçada)
In science fiction, evil overlords and hostile aliens often threaten to vaporize the Earth. At the beginning of The Hitchhikers Guide to the Galaxy, the officiously bureaucratic aliens called Vogons, authors of the third-worst poetry in the universe, actually follow through on the threat, destroying the Earth to make way for a hyperspace bypass.
“We scientists are not content just to talk about vaporizing the Earth,” says Bruce Fegley, professor of earth and planetary sciences at Washington University in St. Louis, tongue firmly in cheek. “We want to understand exactly what it would be like if it happened.”
And in fact Fegley, PhD, and his colleagues Katharina Lodders, PhD, a research professor of earth and planetary sciences who is currently on assignment at the National Science Foundation, and Laura Schaefer, currently a graduate student at Harvard University, have vaporized the Earth—if only by simulation, that is mathematically and inside a computer. Read more ..
Artist’s conception a white dwarf and companion (credit: Casey Reed/NASA/CXC)
Type Ia supernovae are violent stellar explosions. Observations of their brightness are used to determine distances in the universe and have shown scientists that the universe is expanding at an accelerating rate. But there is still too little known about the specifics of the processes by which these supernovae form. New research led by Carnegie’s Stella Kafka identifies a star, prior to explosion, which will possibly become a type Ia supernova. The work will be published in the Monthly Notices of the Royal Astronomical Society.
The widely accepted theory is that type Ia supernovae are thermonuclear explosions of a white dwarf star that’s part of a binary system—two stars that are physically close and orbit around a common center of mass. This white dwarf has mass gradually donated to it by its companion. When the white dwarf mass eventually reaches 1.4 times the sun, it explodes to produce a type Ia supernova. The crucial questions are: What is the nature of the donor star and how does this white dwarf increase its mass. Also, how would that process affect the properties of the explosion? Read more ..
NJIT Distinguished Research Professor and former Bell Labs scientist Louis J. Lanzerotti, will see his 50-year quest to better understand space weather and Earth’s Van Allen Radiation Belts rocket, once again, into space on Aug. 23, 2012. This is when NASA’s twin Radiation Belt Storm Probes (RBSP) begin their mission to study the extremes of space weather. Lanzerotti, today one of the most respected and valued scientists behind space exploration, was the principal investigator to build one of five instruments aboard each of the two spacecraft that comprise the RBSP mission.
The mission is part of NASA’s Living With a Star program, which is managed by Goddard Space Flight Center. The Johns Hopkins University Applied Physics Laboratory (APL) manages the mission and has built and will operate the two RBSP spacecraft for NASA. RBSP begins its exploration with a predawn August 23 launch aboard a United Launch Alliance Atlas V 401 rocket. Each RBSP spacecraft weighs about 660 kilograms (1,455 pounds) and carries an identical set of five instrument suites that will enable scientists to unlock the mysteries of the radiation belts surrounding Earth. Read more ..
An international research collaboration recently demonstrated progress in protecting cassava against cassava brown streak disease (CBSD), a serious virus disease, in a confined field trial in Uganda using an RNA interference technology. The field trial was planted in November 2010 following approval by the National Biosafety Committee of Uganda. The plants were harvested in November 2011. These results point researchers in the right direction as they develop virus-resistant cassava varieties preferred by farmers in Eastern Africa.
In Sub-Saharan Africa, more than 250 million people derive at least 25 percent of their daily calorie intake from the starchy cassava tuberous roots. In the East African countries of Uganda, Kenya, Tanzania, Mozambique, Rwanda, Burundi and Malawi, 63 percent of households also sell cassava products to earn income for their families. It is estimated that in the next 15 years, cassava will constitute the second most important source of income for more than 125 million people in East Africa. Read more ..
Blood, milk, and mucus proteins could soon replace silicon to produce transistors, which amplify electrical signals and are the basis of most modern technology. One of the most important benefits of this discovery is that these transistors will be biodegradable. A team of researchers including students Elad Mentovich and Netta Hendler of TAU’s Department of Chemistry and The Center for Nanoscience and Nanotechnology, with supervisor Shachar Richter and in collaboration with Prof. Michael Gozin and his student Bogdan Belgorodsky, have brought together biology and chemistry to create self- assembling protein-based transistors.
Each organic protein has unique properties and when mixed together can create a complete circuit with electronic and optical capabilities with great flexibility in terms of conductivity, memory storage, and fluorescence. Blood proteins can absorb oxygen, allowing researchers to add different chemicals to adjust the properties of the semiconductor in order to create specific technological properties. Read more ..
For decades it has been thought that a shock wave from a supernova explosion triggered the formation of our Solar System. According to this theory, the shock wave also injected material from the exploding star into a cloud of dust and gas, and the newly polluted cloud collapsed to form the Sun and its surrounding planets. New work from Carnegie's Alan Boss and Sandra Keiser provides the first fully three-dimensional (3-D) models for how this process could have happened. Their work will be published by The Astrophysical Journal Letters.
Traces of the supernova's pollution can be found in meteorites in the form of short-lived radioactive isotopes, or SLRIs. SLRIs—versions of elements with the same number of protons, but a different number of neutrons—found in primitive meteorites decay on time scales of millions of years and turn into different, so-called daughter, elements. A million years may sound like a long time, but it is actually considered short when compared to other radioactive isotopes studied by geochemists and cosmochemists, which have half-lives measured in billions of years. Read more ..
There will be several weeks of testing before NASA turns Curiosity loose to roam about the Martian surface, looking for signs that the planet once might have had conditions suitable to support life. But first the scientists and engineers at the Joint Propulsion Laboratory near Los Angeles did a little celebrating.
NASA described Curiosity’s plunge through the Martian atmosphere as “seven minutes of terror,” but the landing, which engineers said was the most complex ever attempted, proceeded flawlessly. Moments after touchdown the craft sent a picture back to Earth, showing one of its six wheels on the planet’s surface. The first pictures from the craft were received back on Earth almost immediately after confirmation of the landing Monday at about 5:30a.m. UTC. Read more ..
Plants produce toxins to defend themselves against potential enemies, from herbivorous pests to diseases. Oilseed rape plants produce glucosinolates to serve this purpose. However, due to the content of glucosinolates, farmers can only use limited quantities of the protein-rich rapeseed for pig and chicken feed. Now, a team of researchers from the University of Copenhagen has developed a method to hinder unwanted toxins from entering the edible parts of the plant.
"We have developed an entirely new technology that we call 'transport engineering'. It can be used to eliminate unwanted substances from the edible parts of crops," says Professor Barbara Ann Halkier, head of the Center of Excellence for Dynamic Molecular Interactions (DynaMo) at the University of Copenhagen's Faculty of Science.
The oilseed rape plant is but one example of a crop whose use will be greatly enhanced thanks to the new technology. Unlike the healthy glucosinolates found in broccoli, oilseed rape additionally produces a glucosinolate that is harmful to most animals when consumed in larger amounts. Read more ..
NASA has announced new agreements with U.S. companies to develop spacecraft so that astronauts once again can launch from the United States. The U.S. has not had that capability since it retired its space shuttle fleet last year. Now it looks like the launches could happen by the end of 2017.
NASA officials say U.S. reliance on Russia to carry American astronauts to the International Space Station could be over by the end of 2017. NASA Administrator Charles Bolden held a news conference Friday at the Kennedy Space Center in Florida.
"Today we're announcing another critical step toward launching our astronauts from U.S. soil on space systems built by American companies," said Bolden. "We've selected three companies to develop crew transportation capabilities as a fully integrated system and keep us on track to end the outsourcing of our human spaceflight program." Read more ..
Despite suffering from significant oversupply problems, the global memory integrated circuits (IC) market will be driven on by data centers and the advent of cloud computing, expects a new report by international business analysts GBI Research. According to the company's latest report, the increased adoption of cloud computing services among various enterprises and customers is leading to the design and development of memory ICs suitable for shared servers and storage devices.
In-memory cloud computing offers large amounts of memory storage through a new storage tier, and is currently in high demand, with applications such as Apple’s iCloud leading the way. Continuing developments will increase the market of memory ICs, which will in turn help cloud computing infrastructure and data centers to deal with issues related to storage and reliability. The main challenge of such cloud computing infrastructure services is to maintain high system performance at low infrastructure costs, even when data size grows continuously. Advances in flash memory, specifically NAND flash, are of key importance as higher density types enable more applications per server. Read more ..
The U.S. space agency is preparing for its newest Mars rover, Curiosity, to touch down on the Red Planet on August 6. The rover’s entry and descent will be nerve-wracking for NASA engineers, compounded by a 14-minute delay as the rover’s signals travel to Earth from Mars. If successful, Curiosity will be the sixth NASA spacecraft to land on the Red Planet.
Curiosity is a “Mars scientist’s dream machine,” said Deputy Project Scientist Ashwin Vasavada ahead of its launch. “This rover is not only the most technically capable rover ever sent to another planet, but it’s actually the most capable scientific explorer we’ve ever sent out,” he said. Read more ..
Artist’s Conception of a Vampire Star and its Victim (credit: ESO/L. Calçada/S.E. de Mink)
The Universe is a diverse place, and many stars are quite unlike the Sun. An international team has used the VLT to study what are known as O-type stars, which have very high temperature, mass, and brightness. These stars have short and violent lives and play a key role in the evolution of galaxies. They are also linked to extreme phenomena such as “vampire stars”, where a smaller companion star sucks matter off the surface of its larger neighbour, and gamma-ray bursts. Most stars are classified according to their spectral type, or colour. This in turn is related to the stars’ mass and surface temperature. From bluest (and hence hottest and highest mass) to reddest (and hence coolest and lowest mass), the most common classification sequence is O, B, A, F, G, K and M. Our sun is a G-type.
“These stars are absolute behemoths,” says Hugues Sana (University of Amsterdam, Netherlands), the lead author of the study. “They have 15 or more times the mass of our Sun and can be up to a million times brighter. These stars are so hot that they shine with a brilliant blue-white light and have surface temperatures over 30,000° Celsius.” Read more ..