Scientists in Australia have discovered what they say is the largest asteroid impact area ever found. Excerpt from bbc.comThe 400-kilometre (250-mile) wide area is buried deep in the earth's crust and consists of two separate impact scars.The...
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| The Cassiopeia A nebula is the gaseous remnant of a supernova explosion whose light reached the Earth around the year 1680. |
Excerpt from sciencerecorder.com
A recent discovery has revealed that a supernovae is capable enough producing such quantities of cosmic dust that it can yield thousands of Earths.
An international team of researchers analyzed data obtained by SOFIA – a NASA and German Aerospace Center’s Stratospheric Observatory for Infrared Astronomy project – which took images of a cosmic dust cloud.
“This discovery is a special feather in the cap for SOFIA, demonstrating how observations made within our own Milky Way galaxy can bear directly on our understanding of the evolution of galaxies billions of light years away,” said Pamela Marcum, one of the researchers.
SOFIA, an enhanced Boeing 747 with high end telescope, flies in altitudes between 39,000 to 45,000 feet to capture its images.
Astronomers already knew that the shock waves of supernovas produce high concentrations of dust when they move outward.
The question was whether the cosmic particles could withstand the intense shock waves.
“The dust survived the later onslaught of shock waves from the supernova explosion, and is now flowing into the interstellar medium where it can become part of the ‘seed material’ for new stars and planets,” said Ryan Lau, of Cornell University, who led the research team.
This new discovery encouraged the idea that the vast quantities of dust seen in remote yet fairly young galaxies may have been produced by the explosions of large stars that were actually much older.
The research was published in Science magazine on Thursday.
Excerpt from educatinghumanity.com "Anyone not shocked by quantum mechanics has not yet understood it."Niels Bohr10 Ways Quantum Physics Will Change the WorldEver want to have a "life do over", teleport, time travel, have your computer wor...
Excerpt from chroniclebulletin.com University of Colorado-led Mars mission has observed two unexpected phenomena in the Martian atmosphere, unveiled Wednesday at the 46th Lunar and Planetary Science Conference in Texas.NASA describes the finds by MA...
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| CGI of how the Milky Way galaxy may appear from deep space |
Excerpt from thespacereporter.com
Analysis of data collected by NASA’s Kepler space telescope has led researchers at the Australian National University and the Niels Bohr Institute to conclude that Earth is only one of billions of potentially life-sustaining planets in our galaxy.
In order for a planet to sustain life, it must orbit its star at just the right distance to provide sufficient light and warmth to maintain liquid water without too much radiation. This perfect orbital distance is considered to be the habitable zone.
According to a Weather Channel report, there are an average of two planets per star in the Milky Way Galaxy orbiting within their habitable zones. That brings the total number of planets with the potential for holding liquid water to 100 billion.
Scientists assume that water would be an essential ingredient for life to evolve on other planets, but it is not a certainty.
“If you have liquid water, then you should have better conditions for life, we think,” said Steffen Jacobsen of Niels Bohr. “Of course, we don’t know this yet. We can’t say for certain.”
To reach their conclusion, the researchers studied 151 planetary systems and focused on those with four or more planets. They used a concept called the Titus-Bode law to calculate where unseen planets might be located in a system based on the placements of other planets around the star. The Titus-Bode law suggested the existence of Uranus before it was actually seen.
The data will require further analysis and the sky will require further searching to yield a more accurate number of potentially life-harboring planets.
“Some of these planets are so small the Kepler team will probably have missed them in the first attempt because the signals we get are so weak. They may be hidden in the noise,” Jacobsen said.
The initial analysis, however, is extremely promising in the possibility of finding habitable planets. “Our research indicates that there are a lot of planets in the habitable zone and we know there are a lot of stars like the one we’re looking at. We know that means we’re going to have many billions of planets in the habitable zone,” said Jacobsen, who considers that “very good news for the search for life.”
Excerpt from smithsonianmag.com
In the hunt for alien life, our first glimpse of extraterrestrials may be in the rainbow of colors seen coming from the surface of an exoplanet.
That's the deceptively simple idea behind a study led by Siddharth Hegde at the Max Planck Institute for Astronomy in Germany. Seen from light-years away, plants on Earth give our planet a distinctive hue in the near-infrared, a phenomenon called red edge. That's because the chlorophyll in plants absorbs most visible light waves but starts to become transparent to wavelengths on the redder end of the spectrum. An extraterrestrial looking at Earth through a telescope could match this reflected color with the presence of oxygen in our atmosphere and conclude there is life here.
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| Eight of the 137 microorganism samples used to measure biosignatures for the catalog of reflection signatures of Earth life forms. In each panel, the top is a regular photograph of the sample and the bottom is a micrograph, a version of the top image zoomed-in 400 times. |
Plants, though, have only been around for 500 million years—a relative blip in our planet's 4.6-billion-year history. Microbes dominated the scene for some 2.5 billion years in the past, and some studies suggest they will rule the Earth again for much of its future. So Hegde and his team gathered 137 species of microorganisms that all have different pigments and that reflect light in specific ways. By building up a library of the microbes' reflectance spectra—the types of colors those microscopic critters reflect from a distance—scientists examining the light from habitable exoplanets can have a plethora of possible signals to search for, the team argues this week in the Proceedings of the National Academy of Sciences.
"No one had looked at the wide range of diverse life on Earth and asked how we could potentially spot such life on other planets, and include life from extreme environments on Earth that could be the 'norm' on other planets," Lisa Kaltenegger, a co-author on the study, says via email. "You can use it to model an Earth that is different and has different widespread biota and look how it would appear to our telescopes."
To make sure they got enough diversity, the researchers looked at temperate-dwelling microbes as well as creatures that live in extreme environments like deserts, mineral springs, hydrothermal vents or volcanically active areas.
While it might seem that alien life could take a huge variety of forms—for instance, something like the silicon-based Horta from Star Trek—it's possible to narrow things down if we restrict the search to life as we know it. First, any life-form that is carbon-based and uses water as a solvent isn't going to like the short wavelengths of light far in the ultraviolet, because this high-energy UV can damage organic molecules. At the other end of the spectrum, any molecule that alien plants (or their analogues) use to photosynthesize won't be picking up light that's too far into the infrared, because there's not enough energy at those longer wavelengths.
In addition, far-infrared light is hard to see through an Earth-like atmosphere because the gases block a lot of these waves, and whatever heat the planet emits will drown out any signal from surface life. That means the researchers restricted their library to the reflected colors we can see when looking at wavelengths in the visible part of the spectrum, the longest wavelength UV and short-wave infrared.
The library won't be much use if we can't see the planets' surfaces in the first place, and that's where the next generation of telescopes comes in, Kaltenegger says. The James Webb Space Telescope, scheduled for launch in 2018, should be able to see the spectra of relatively small exoplanet atmospheres and help scientists work out their chemical compositions, but it won't be able to see any reflected spectra from material at the surface. Luckily, there are other planned telescopes that should be able to do the job. The European Extremely Large Telescope, a 40-meter instrument in Chile, will be complete by 2022. And NASA's Wide Field Infrared Survey Telescope, which is funded and in its design stages, should be up and running by the mid-2020s.
Another issue is whether natural geologic or chemical processes could look like life and create a false signal. So far the pigments from life-forms look a lot different from those reflected by minerals, but the team hasn't examined all the possibilities either, says Kaltenegger. They hope to do more testing in the future as they build up the digital library, which is now online and free for anyone to explore at biosignatures.astro.cornell.edu.
GanymedeExcerpt from latimes.comAstronomers have found the most conclusive evidence yet that a large watery ocean lies beneath the surface of Jupiter's moon Ganymede.Scientists have suspected for decades that a subterranean ocean ...
Excerpt from cbsnews.com Rings of stars thought to surround the Milky Way are actually part of it, according to new research, meaning the galaxy is bigger than previously believed.The findings extend the known width of the Milk...
Excerpt from cnet.com
Astronomers have mapped the Milky Way's position to the outskirts of a supercluster of galaxies, newly dubbed Laniakea, meaning "Immense Heaven".
Click to zoom
But this Local Group is just a small part of a much, much bigger structure, which researchers at the University of Hawai'i Mānoa have now mapped in detail. Coming in at over 100,000 galaxies, the massive supercluster has been given the name Laniakea -- "immense heaven" in Hawaiian.
The new 3D map was created by examining the positions and movements of the 8000 closest galaxies to the Milky Way. After calculating which galaxies were being pulled away from us and which were being pulled towards us -- accounting for the universe's expansion -- the team, led by astronomer R. Brent Tully, was able to map the paths of galactic migration -- and define the boundaries of Laniakea.
Traditionally, the borders of galactic superclusters have been difficult to map, but studying the gravitational force acting on our neighbouring galaxies has provided some important clues. All objects inside Laniakea are being slowly but surely drawn to a single point -- a force known as the Great Attractor, a gravitational anomaly with a mass tens of thousands of times the mass of the Milky Way.
Everything that is being pulled towards the Great Attractor is part of Laniakea -- although it's possible that Laniakea itself might in turn be part of a structure that is larger still.
"We probably need to measure to another factor of three in distance to explain our local motion," Tully said. "We might find that we have to come up with another name for something larger than we're a part of -- we're entertaining that as a real possibility."
The full paper, "The Laniakea supercluster of galaxies", can be read online in the journal Nature.
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| Astronomers in Brazil have discovered a cluster of stars forming at the edge of the Milky Way, according to a press release from the Royal Astronomical Society. |
Excerpt from news.discovery.com
This is unusual because it was believed that stars generally take form closer to the center of our spiral-shaped galaxy, rather than from its swirling, spiral arms, which are thousands of light-years away. These two clusters of stars — named Camargo 438 and 439 — were seen in a cloud at the galaxy’s outskirts.
Denilso Camargo, an astronomer at the Federal University of Rio Grande do Sul in Porto Alegre, Brazil, led a team that analyzed data from NASA’s orbiting Wide-Field Infrared Survey Explorer (WISE) observatory. They zeroed in on dense clumps of gas in so-called giant molecular clouds(GMCs) that are known to generate stars. GMCs are mainly located in the inner part of the galactic disc.
The new star clusters lie about 16,000 light-years away from the main disk of the Milky Way galaxy. How did they form there? The scientists aren’t yet sure but Camargo theorizes that one of two scenarios could have led to the stars’ formation.
In the first scenario, called the “chimney model,” supernovas could have flung the gas and dust that formed the cloud out of the Milky Way. Another explanation is the material could have drifted in from outside the galaxy.
“Our work shows that the space around the Galaxy is a lot less empty that we thought,” said Camargo. “The new clusters of stars are truly exotic.”
Camargo’s team published their results in the journal Monthly
Jerdon's BabblerExcerpt from techtimes.comJerdon's Babbler is a species of bird that was believed to be extinct until this species unexpectedly resurfaced in Myanmar. This brown and white bird is roughly the size of a house sparrow.The bird was last ...
Excerpt from independent.co.uk
By Jordan Gaines Lewis
In neuroscience, food is something we call a “natural reward.” In order for us to survive as a species, things like eating, having sex and nurturing others must be pleasurable to the brain so that these behaviours are reinforced and repeated.
Evolution has resulted in the mesolimbic pathway, a brain system that deciphers these natural rewards for us. When we do something pleasurable, a bundle of neurons called the ventral tegmental area uses the neurotransmitter dopamine to signal to a part of the brain called the nucleus accumbens. The connection between the nucleus accumbens and our prefrontal cortex dictates our motor movement, such as deciding whether or not to taking another bite of that delicious chocolate cake. The prefrontal cortex also activates hormones that tell our body: “Hey, this cake is really good. And I’m going to remember that for the future.”Not all foods are equally rewarding, of course. Most of us prefer sweets over sour and bitter foods because, evolutionarily, our mesolimbic pathway reinforces that sweet things provide a healthy source of carbohydrates for our bodies. When our ancestors went scavenging for berries, for example, sour meant “not yet ripe,” while bitter meant “alert – poison!”
Fruit is one thing, but modern diets have taken on a life of their own. A decade ago, it was estimated that the average American consumed 22 teaspoons of added sugar per day, amounting to an extra 350 calories; it may well have risen since then. A few months ago, one expert suggested that the average Briton consumes 238 teaspoons of sugar each week.
Today, with convenience more important than ever in our food selections, it’s almost impossible to come across processed and prepared foods that don’t have added sugars for flavour, preservation, or both.
These added sugars are sneaky – and unbeknown to many of us, we’ve become hooked. In ways that drugs of abuse – such as nicotine, cocaine and heroin – hijack the brain’s reward pathway and make users dependent, increasing neuro-chemical and behavioural evidence suggests that sugar is addictive in the same way, too.
Sugar addiction is real
Anyone who knows me also knows that I have a huge sweet tooth. I always have. My friend and fellow graduate student Andrew is equally afflicted, and living in Hershey, Pennsylvania – the “Chocolate Capital of the World” – doesn’t help either of us. But Andrew is braver than I am. Last year, he gave up sweets for Lent. “The first few days are a little rough,” Andrew told me. “It almost feels like you’re detoxing from drugs. I found myself eating a lot of carbs to compensate for the lack of sugar.”There are four major components of addiction: bingeing, withdrawal, craving, and cross-sensitisation (the notion that one addictive substance predisposes someone to becoming addicted to another). All of these components have been observed in animal models of addiction – for sugar, as well as drugs of abuse.
A typical experiment goes like this: rats are deprived of food for 12 hours each day, then given 12 hours of access to a sugary solution and regular chow. After a month of following this daily pattern, rats display behaviours similar to those on drugs of abuse. They’ll binge on the sugar solution in a short period of time, much more than their regular food. They also show signs of anxiety and depression during the food deprivation period. Many sugar-treated rats who are later exposed to drugs, such as cocaine and opiates, demonstrate dependent behaviours towards the drugs compared to rats who did not consume sugar beforehand.
Like drugs, sugar spikes dopamine release in the nucleus accumbens. Over the long term, regular sugar consumption actually changes the gene expression and availability of dopamine receptors in both the midbrain and frontal cortex. Specifically, sugar increases the concentration of a type of excitatory receptor called D1, but decreases another receptor type called D2, which is inhibitory. Regular sugar consumption also inhibits the action of the dopamine transporter, a protein which pumps dopamine out of the synapse and back into the neuron after firing.
In short, this means that repeated access to sugar over time leads to prolonged dopamine signalling, greater excitation of the brain’s reward pathways and a need for even more sugar to activate all of the midbrain dopamine receptors like before. The brain becomes tolerant to sugar – and more is needed to attain the same “sugar high.”
Sugar withdrawal is also real
Although these studies were conducted in rodents, it’s not far-fetched to say that the same primitive processes are occurring in the human brain, too. “The cravings never stopped, [but that was] probably psychological,” Andrew told me. “But it got easier after the first week or so.”In a 2002 study by Carlo Colantuoni and colleagues of Princeton University, rats who had undergone a typical sugar dependence protocol then underwent “sugar withdrawal.” This was facilitated by either food deprivation or treatment with naloxone, a drug used for treating opiate addiction which binds to receptors in the brain’s reward system. Both withdrawal methods led to physical problems, including teeth chattering, paw tremors, and head shaking. Naloxone treatment also appeared to make the rats more anxious, as they spent less time on an elevated apparatus that lacked walls on either side.
Similar withdrawal experiments by others also report behaviour similar to depression in tasks such as the forced swim test. Rats in sugar withdrawal are more likely to show passive behaviours (like floating) than active behaviours (like trying to escape) when placed in water, suggesting feelings of helplessness.
A new study published by Victor Mangabeira and colleagues in this month’s Physiology & Behavior reports that sugar withdrawal is also linked to impulsive behaviour. Initially, rats were trained to receive water by pushing a lever. After training, the animals returned to their home cages and had access to a sugar solution and water, or just water alone. After 30 days, when rats were again given the opportunity to press a lever for water, those who had become dependent on sugar pressed the lever significantly more times than control animals, suggesting impulsive behaviour.
These are extreme experiments, of course. We humans aren’t depriving ourselves of food for 12 hours and then allowing ourselves to binge on soda and doughnuts at the end of the day. But these rodent studies certainly give us insight into the neuro-chemical underpinnings of sugar dependence, withdrawal, and behaviour.
Through decades of diet programmes and best-selling books, we’ve toyed with the notion of “sugar addiction” for a long time. There are accounts of those in “sugar withdrawal” describing food cravings, which can trigger relapse and impulsive eating. There are also countless articles and books about the boundless energy and new-found happiness in those who have sworn off sugar for good. But despite the ubiquity of sugar in our diets, the notion of sugar addiction is still a rather taboo topic.
Are you still motivated to give up sugar? You might wonder how long it will take until you’re free of cravings and side-effects, but there’s no answer – everyone is different and no human studies have been done on this. But after 40 days, it’s clear that Andrew had overcome the worst, likely even reversing some of his altered dopamine signalling. “I remember eating my first sweet and thinking it was too sweet,” he said. “I had to rebuild my tolerance.”
And as regulars of a local bakery in Hershey – I can assure you, readers, that he has done just that.
Jordan Gaines Lewis is a Neuroscience Doctoral Candidate at Penn State College of Medicine
Excerpt from paranormal.lovetoknow.com By Michelle Radcliff The Bermuda Triangle is an area of mostly open ocean located between Bermuda, Miami, Florida and San Juan, Puerto Rico. The unexplained disappearances of hundreds of ships and air...
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