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Space

Brown Dwarf With Water Clouds Tentatively Detected Just 7 Light-Years From Earth 85

sciencehabit (1205606) writes Astronomers have found signs of water ice clouds on an object just 7.3 light-years from Earth — less than twice the distance of Alpha Centauri. If confirmed, the discovery is the first sighting of water clouds beyond our solar system. The clouds shroud a Jupiter-sized object known as a brown dwarf and should yield insight into the nature of cool giant planets orbiting other suns.
Space

Exomoon Detection Technique Could Greatly Expand Potential Habitable Systems 66

Luminary Crush (109477) writes Most of the detected exoplanets thus far have been gas giants which aren't great candidates for life as we know it. However, many of those planets are in fact in the star's habitable zone and could have moons with conditions more favorable. Until now, methods to detect the moons of such gas giants have been elusive, but researchers at the University of Texas, Arlington have discovered a way to detect the interaction of a moon's ionosphere with the parent gas giant from studies of Jupiter's moon Io. The search for 'Pandora' has begun.
NASA

NASA's Greenhouse Gas Observatory Captures 'First Light' 143

mdsolar (1045926) writes with news that NASA's second attempt to launch a satellite to map carbon dioxide levels across the globe succeeded, and its instruments are operating properly. From the article: NASA's first spacecraft dedicated to studying Earth's atmospheric climate changing carbon dioxide levels and its carbon cycle has reached its final observing orbit and taken its first science measurements as the leader of the world's first constellation of Earth science satellites known as the International 'A-Train. The Orbiting Carbon Observatory-2 (OCO-2) is a research satellite tasked with collecting the first global measurements of atmospheric carbon dioxide (CO2) — the leading human-produced greenhouse gas and the principal human-produced driver of climate change. The 'first light' measurements were conducted on Aug. 6 as the observatory flew over central Papua New Guinea and confirmed the health of the science instrument.
Space

Google's Satellites Could Soon See Your Face From Space 140

Jason Koebler (3528235) writes Two months ago, after much lobbying by the biggest satellite company in North America, DigitalGlobe, the US government relaxed restrictions to allow for commercially available satellite imagery up to 25 cm resolution—twice as detailed as the previous limit of 50 cm.
The DigitalGlobe's Worldview-3, the first commercial satellite set to capture these high-res images is set to launch this Wednesday. Six months after that, private businesses, including its regular client Google, will be able to get their hands on hyper-detailed photos and videos of the globe.
Space

SpaceX Chooses Texas Site For Private Spaceport 113

AcidPenguin9873 (911493) writes Today, Texas Gov. Rick Perry and SpaceX CEO Elon Musk announced that SpaceX has chosen a site at Boca Chica Beach, Texas, as the location where SpaceX will build its rocket launch facility. The Boca Chica site, at the southern tip of Texas near Brownsville and South Padre Island, had been competing with sites in Florida, Georgia, and Puerto Rico, but had been named the frontrunner to land the site by Musk when he testified to the Texas state legislature in 2013. The spaceport will be the first privately-owned vertical rocket launch facility in the world, and will target commercial customers. State and local governments have pledged to provide a total of about $20 million in incentives to attract SpaceX to the site.
NASA

NASA Tests Microwave Space Drive 201

schwit1 (797399) writes with news that NASA scientists have tested the EmDrive, which claims to use quantum vacuum plasma for propulsion. Theoretically improbable, but perhaps possible after all. If it does work, it would eliminate the need for expendable fuel (just add electricity). From the article:Either the results are completely wrong, or NASA has confirmed a major breakthrough in space propulsion. A working microwave thruster would radically cut the cost of satellites and space stations and extend their working life, drive deep-space missions, and take astronauts to Mars in weeks rather than months. ... [According to the researchers] "Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma." Skepticism is certainly warranted: NASA researchers were only able to produce about 1/1000th of the force the Chinese researchers reported. But they were careful to avoid false sensor readings, so something is going on. The paper declined to comment on what that could be, leaving the physics of the system an open problem.
Space

Black Holes Not Black After All, Theorize Physicists 227

KentuckyFC (1144503) writes Black holes are singularities in spacetime formed by stars that have collapsed at the end of their lives. But while black holes are one of the best known ideas in cosmology, physicists have never been entirely comfortable with the idea that regions of the universe can become infinitely dense. Indeed, they only accept this because they can't think of any reason why it shouldn't happen. But in the last few months, just such a reason has emerged as a result of intense debate about one of cosmology's greatest problems — the information paradox. This is the fundamental tenet in quantum mechanics that all the information about a system is encoded in its wave function and this always evolves in a way that conserves information. The paradox arises when this system falls into a black hole causing the information to devolve into a single state. So information must be lost.

Earlier this year, Stephen Hawking proposed a solution. His idea is that gravitational collapse can never continue beyond the so-called event horizon of a black hole beyond which information is lost. Gravitational collapse would approach the boundary but never go beyond it. That solves the information paradox but raises another question instead: if not a black hole, then what? Now one physicist has worked out the answer. His conclusion is that the collapsed star should end up about twice the radius of a conventional black hole but would not be dense enough to trap light forever and therefore would not be black. Indeed, to all intents and purposes, it would look like a large neutron star.
Space

Brazil Nut Effect Explains Mystery of the Boulder-Strewn Surfaces of Asteroids 58

KentuckyFC (1144503) writes When Japan's Hayabusa spacecraft gently maneuvered into a parking orbit around the asteroid Itokawa in September 2005, it conducted a comprehensive photographic survey, the most detailed ever taken of an asteroid. This survey revealed that Itokawa is covered in large boulders that look like ejecta from craters in other parts of the asteroid. But when astronomers added up the total volume of these boulders, it turned out to be greater than the volume of the craters there were supposed to have come from. Other asteroids also show a similarly skewed distribution of large boulders. That has caused some significant head-scratching among astronomers who are at a loss to explain where the boulders come from.

Now an international team has solved the mystery. They say the boulders float to the surface of asteroids in an astrophysical example of the Brazil nut effect. This is the long observed phenomenon in which shaking a mixture of big and small particles causes the larger ones to rise to the top. That's because the shaking creates gaps beneath the large particles that small particles fall into. The result is that the large particles float. The team simulated the shaking effect that collisions between asteroids would produce and say that these vibrations would cause large boulders to float to the surface in a few hours, finally explaining why asteroids have such boulder-strewn surfaces. Problem solved!
Space

Two Earth-Like Exoplanets Don't Actually Exist 102

Two suspected exoplanets, Gliese 581g and 581d, have been shown to not exist, and are instead misinterpretations of data from starspot activity. From the article: "Gliese 581g doesn't exist," said lead author Paul Robertson of Penn State University in State College, Pennsylvania. Neither, he said, does another planet in the same solar system, known as Gliese 581d, announced in 2009—less clearly hospitable to life, but still once seen by some astronomers as a possible place to find aliens. ... What's happening, they say, is that magnetic disturbances on Gliese 581's surface — starspots — are altering the star's spectrum in such a way that it mimics the motion induced by a planet. The star itself rotates once every 130 days, carrying the starspots with it; the disputed planets appeared to have periods of almost exactly one half and one fourth of the 130-day period. When the scientists corrected for the starspot signal, both planets disappeared.
Space

Red Dwarfs Could Sterilize Alien Worlds of Life 76

astroengine (1577233) writes "Red dwarf stars — the most common stars in the galaxy — bathe planets in their habitable zones with potentially deadly stellar winds, a finding that could have significant impacts on the prevalence of life beyond Earth, new research shows. About 70 percent of stars are red dwarfs, or M-type stars, which are cooler and smaller than the sun. Any red dwarf planets suitable for liquid water, therefore, would have to orbit much closer to their parent star than Earth circles the sun. That presents a problem for life — at least life as we know it on Earth, says physicist Ofer Cohen, with the Harvard-Smithsonian Center for Astrophysics. Cohen and colleagues used a computer model based on data from the sun's solar wind — a continuous stream of charged particles that permeates and defines the solar system –- to estimate the space environment around red dwarf stars. 'We find that the conditions are very extreme. If you move planets very close to the star, the force of this flow is very, very strong. Essentially it can strip the atmosphere of the planet unless the planet has a strong magnetic field or a thick atmosphere to start with,' Cohen told Discovery News."
Space

The Andromeda Galaxy Just Had a Bright Gamma Ray Event 129

First time accepted submitter SpaceMika (867804) writes "We just saw something bright in the Andromeda Galaxy, and we don't know what it was. A Gamma Ray Burst or an Ultraluminous X-Ray Object, either way it will be the closest of its type we've ever observed at just over 2 million light years away. It's the perfect distance: close enough to observe in unprecedented detail, and far enough to not kill us all."
Space

NASA's Plan To Block Light From Distant Stars To Find 'Earth 2.0' 92

Daniel_Stuckey (2647775) writes "Over the last five years, NASA's Kepler Space Telescope has found dozens of potentially habitable planets. The only problem is that we can't actually see them, because the glare from those planets' stars makes it impossible to image them directly. A new, audacious plan to completely block out the light from those stars, however, could change all of that. The plan calls for a satellite to be sent out several tens of thousands of miles from Earth. The satellite will unfold a huge, flower-shaped metal shade that will literally block the light of some far-out star to the point where a space telescope, which will directly communicate with Starshade, will be able to image whatever planets are orbiting it directly. It's called Starshade, and, given the name, it works exactly how you might expect it to. If you look directly at the sun, you're not going to be able to see anything in the sky around it. Hold up something between your eyes and the sun to block it, however, and you'll be able to see much better."
Space

Supermassive Black Hole At the Centre of Galaxy May Be Wormhole In Disguise 293

KentuckyFC (1144503) writes "There is growing evidence that the center of the Milky Way contains a mysterious object some 4 million times more massive than the Sun. Many astronomers believe that this object, called Sagittarius A*, is a supermassive black hole that was crucial in the galaxy's birth and formation. The thinking is that about 100 million years after the Big Bang, this supermassive object attracted the gas and dust that eventually became the Milky Way. But there is a problem with this theory--100 million years is not long enough for a black hole to grow so big. The alternative explanation is that Sagittarius A* is a wormhole that connects the Milky Way to another region of the universe or even a another multiverse. Cosmologists have long known that wormholes could have formed in the instants after the Big Bang and that these objects would have been preserved during inflation to appear today as supermassive objects hidden behind an event horizon, like black holes. It's easy to imagine that it would be impossible to tell these objects apart. But astronomers have now worked out that wormholes are smaller than black holes and so bend light from an object orbiting close to them, such as a plasma cloud, in a unique way that reveals their presence. They've even simulated what such a wormhole will look like. No telescope is yet capable of resolving images like these but that is set to change too. An infrared instrument called GRAVITY is currently being prepared for the Very Large Telescope Interferometer in Chile and should be in a position to spot the signature of a wormhole, if it is there, in the next few years."
Space

The Strange Death of Comet Ison 49

KentuckyFC (1144503) writes "Last year, astronomers announced that a small ball of ice and rock heading towards the inner Solar System could turn out to be the most eye-catching comet in living memory. They calculated that Comet Ison's orbit would take it behind the Sun but that it would then head towards Earth where it would put on a spectacular display of heavenly fireworks. Sure enough, Ison brightened dramatically as it headed Sunwards. But as astronomers watched on the evening of 28 November, the brightly flaring Ison moved behind the Sun but never emerged. The comet simply disappeared. Now a new analysis of the death of Ison suggests that the comet was doomed long before it reached the Sun. Images from several Sun-observing spacecraft that had a unique view of events, indicate that Ison exhausted its supply of water and other ice in the final flare-ups as it approached the Sun. The new study shows that all that was left in its last hours were a few hundred thousands pebbles glowing brightly as they vaporized in the Sun's heat. In fact, Comet Ison died in full view of the watching hordes of astronomers on Earth who did not realize what they were watching at the time."
Space

Proposed Indicator of Life On Alien Worlds May Be Bogus 112

sciencehabit (1205606) writes with bad news for anyone hoping to use the spectral signatures of exoplanets to determine if their atmospheres have life-enabling compositions. "Call it the cosmic version of fool's gold. What was once considered a sure-fire sign of life on distant planets may not be so sure-fire after all, a new study suggests. The signal—a strong chemical imbalance in the planet's atmosphere that could only be generated by thriving ecosystems—could instead be the combined light from a lifeless exoplanet and its equally barren moon."

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