63134843
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astroengine writes:
New observations from NASA’s Saturn-orbiting Cassini spacecraft have revealed at least 101 individual geysers erupting from Enceladus’ crust and, through careful analysis, planetary scientists have uncovered their origin. From the cracked ice in this region, fissures blast out water vapor mixed with organic compounds as huge geysers. Associated with these geysers are surface “hotspots” but until now there has been some ambiguity as to whether the hotspots are creating the geysers or whether the geysers are creating the hotspots. “Once we had these results in hand, we knew right away heat was not causing the geysers, but vice versa,” said Carolyn Porco, leader of the Cassini imaging team from the Space Science Institute in Boulder, Colo., and lead author of one of the research papers. “It also told us the geysers are not a near-surface phenomenon, but have much deeper roots.” And those roots point to a large subsurface source of liquid water — adding Enceladus as one of the few tantalizing destinations for future astrobiology missions.
62605295
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astroengine writes:
Physicists aren’t afraid of thinking big, but what happens when you think too big? This philosophical question overlaps with real physics when hypothesizing what lies beyond the boundary of our observable universe. The problem with trying to apply science to something that may or may not exist beyond our physical realm is that it gets a little foggy as to how we could scientifically test it. A leading hypothesis to come from cosmic inflation theory and advanced theoretical studies — centering around the superstring hypothesis — is that of the "multiverse," an idea that scientists have had a hard time in testing. But now, scientists at the Perimeter Institute for Theoretical Physics, in Ontario, Canada, have, for the first time, created a computer model of colliding universes in the multiverse in an attempt to seek out observational evidence of its existence.
62501465
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astroengine writes:
Ukrainian government officials say Russian-backed rebel forces shot down a Malaysian Airlines flight with 295 passengers and crew over the embattled border region on its way from Amsterdam to Kuala Lumpur. The commercial flight was cruising at 33,000 feet, making it too high for a shoulder-launched missile and more likely that it was targeted by a radar-guided missile defense system, according to military experts. “It does seem depressingly likely,” said Mark Galeotti, a professor of global affairs at New York University currently studying Russian security issues in Moscow. “We know the rebels have the Buk missile system. We know they have shot down planes in the past. They may have believed it was a legitimate target.” Although the Buk system is designed to shoot down fast-moving military aircraft, a high-flying jetliner would have been an easy target. And although it would have been carrying a civilian transponder, if the anti-aircraft missile was being operated by a novice controller, mistakes were most likely made.
62495571
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astroengine writes:
To find life on Mars, some scientists believe you might want to look underground for microbes that may be hiding from the harsh radiation that bathes the red planet’s surface. Various NASA rovers have scraped away a few inches at a time, but the real paydirt may lie a meter or two below the surface. That’s too deep for existing instruments, so a team of space enthusiasts has launched a more ambitious idea: dropping arrow-like probes from the Martian atmosphere to pierce the soil like bunker-busting bug catchers. The “ExoLance” project aims to drop ground-penetrating devices, each of which would carry a small chemical sampling test to find signs of life. “One of the benefits of doing this mission is that there is less engineering,” said Chris Carberry, executive director of Explore Mars, a non-profit space advocacy group pushing the idea. “With penetrators we can engineer them to get what we want, and send it back to an orbiter. We can theoretically check out more than one site at a time. We could drop five or six, which increases the chances of finding something.”
62080999
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astroengine writes:
How cosmic dust is created has been a mystery for some time. Although the textbooks tell us that the dusty stuff that builds the planets — and, ultimately, the complex chemistry that forms life (we are, after all, made of ‘star stuff’) — comes from supernova explosions, astronomers have been puzzled as to how delicate grains of dust condense from stellar material and how they can possibly survive the violent shock waves of the cataclysmic booms. But now, with the help of a powerful ground-based telescope, astronomers have not only watched one of these supernova ‘dust factories’ in action, they’ve also discovered how the grains can withstand the violent supernova shock. “When the star explodes, the shockwave hits the dense gas cloud like a brick wall,” said lead author Christa Gall, of Aarhus University, Denmark. “It is all in gas form and incredibly hot, but when the eruption hits the ‘wall’ the gas gets compressed and cools down to about 2,000 degrees. At this temperature and density elements can nucleate and form solid particles. We measured dust grains as large as around one micron (a thousandth of a millimeter), which is large for cosmic dust grains. They are so large that they can survive their onward journey out into the galaxy.” The surprising size of the measured dust particles means they can better survive the supernova's shockwave. This research has been published in the journal Nature.
61503395
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astroengine writes:
This may seem a little far fetched, but if our understanding of the physics behind the recently-discovered Higgs boson (or, more specifically, the Higgs field — the ubiquitous field that endows all stuff with mass) is correct, our Universe shouldn’t exist. That is, however, if another cosmological hypothesis is real, a hypothesis that is currently undergoing intense scrutiny in light of the BICEP2 results.
60842057
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astroengine writes:
A weird type of ‘hybrid’ star has been discovered nearly 40 years since it was first theorized — but until now has been curiously difficult to find. In 1975, renowned astrophysicists Kip Thorne, of the California Institute of Technology (Caltech) in Pasadena, Calif., and Anna Zytkow, of the University of Cambridge, UK, assembled a theory on how a large dying star could swallow its neutron star binary partner, thus becoming a very rare type of stellar hybrid, nicknamed a Thorne-Zytkow object (or TZO). The neutron star — a dense husk of degenerate matter that was once a massive star long since gone supernova — would spiral into the red supergiant’s core, interrupting normal fusion processes. According to the Thorne-Zytkow theory, after the two objects have merged, an excess of the elements rubidium, lithium and molybdenum will be generated by the hybrid. So astronomers have been on the lookout for stars in our galaxy, which is thought to contain only a few dozen of these objects at any one time, with this specific chemical signature in their atmospheres. Now, according to Emily Levesque of the University of Colorado Boulder and her team, a bona fide TZO has been discovered and their findings have been accepted for publication in the Monthly Notices of the Royal Astronomical Society Letters.
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astroengine writes:
Meet “mega-Earth” a souped-up, all-solid planet that, according to theory, should not exist. First spotted by NASA’s Kepler space telescope, the planet is about 2.3 times larger than Earth. Computer models show planets that big would be more like Neptune or the other gas planets of the outer solar system since they would have the gravitational heft to collect vast amounts of hydrogen and helium from their primordial cradles. But follow-up observations of the planet, designated as Kepler-10c, show it has 17 times as much mass as Earth, meaning it must be filled with rock and other materials much heavier than hydrogen and helium. “Kepler-10c is a big problem for the theory,” astronomer Dimitar Sasselov, director of the Harvard Origins of Life Initiative, told Discovery News. “It’s nice that we have a solid piece of evidence and measurements for it because that gives motivations to the theorists to improve the theory,” he said.
60760193
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astroengine 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.
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astroengine writes:
Could ET be chatting with colleagues or robots on sister planets in its solar system? Maybe so, say scientists who last year launched a new type of Search for Extraterrestrial Intelligence, or SETI, project to eavesdrop on aliens. Using data collected by NASA’s Kepler space telescope, a team of scientists spent 36 hours listening in when planets in targeted solar systems lined up, relative to Earth’s perspective, in hopes of detecting alien interplanetary radio signals. “We think the right strategy in SETI is a variety of strategies. It’s really hard to predict what other civilizations might be doing,” Dan Werthimer, director of SETI research at the University of California Berkeley, told Discovery News. So far the search hasn't turned up any artificial signals yet, but this marks a change in strategy for radio searches for ETI with Kepler data taking a focused lead.
60365795
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astroengine writes:
The asteroid that hit Earth last year and exploded over Chelyabinsk, Russia, had a prior crash record. Fragments of the asteroid recovered after the powerful Feb. 15, 2013, airburst show it contained an unusual form of the mineral jadeite embedded in glassy structures known as shock veins. Shock veins typically form when the parent body of a meteor or asteroid collides with a larger object in space. Heat and pressure from the impact cause rock to melt. It later reforms bearing vein-shaped patterns. “Impact-induced jadeite has been found from other shocked meteorites. However, a unique point of the Chelyabinsk jadeite is that it seems to have crystallized from melt. To my knowledge, previously reported jadeite in other meteorites is considered to have formed (by solid-state reaction) without melting,” graduate student Shin Ozawa, with Japan’s Tohoku University, wrote in an email to Discovery News.
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astroengine writes:
Curious about whether there is life beyond Earth? The answer should come within 20 years, astronomers told members of a Congressional science committee on Wednesday. A three-way race is under way to learn if life exists elsewhere in the solar system or beyond, Seth Shostak, senior astronomer with the California-based SETI Institute, said during a hearing before the House Science and Technology Committee. So far, most efforts — and funding — to find extraterrestrial life have focused on Mars and potential life-bearing moons in the outer solar system. “At least a half-dozen other worlds (besides Earth) that might have life are in our solar system. The chances of finding it, I think, are good, and if that happens, it’ll happen in the next 20 years, depending on the financing,” Shostak said.
59829755
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astroengine writes:
The people of planet Earth would be wise to raise their cosmic consciousness prior to contact with an extraterrestrial civilization, a new study shows. “The scientific community now accepts to some degree that this contact may occur in the next 50 to 100 years,” said Gabriel De la Torre, a clinical neuropsychologist and human factors specialist at the University of Cádiz in Spain. “Consequently, we are becoming more concerned about this possibility and its aftermath Certainly the topic of contact with extraterrestrial civilizations raises a number of questions that are not easy to answer. We estimate that this type of event will have not only a social effect, but also on both consciousness and biology as well.” Although we may not have the necessary social skillset to deal with an encounter of the third kind, scientists or astronauts might make the best candidates for the first alien conversation.
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astroengine writes:
We thought we had star formation mechanisms pinned down, but according to new observations of two star clusters, it seems our understanding of how stars are born is less than stellar. When zooming in on the young star clusters of NGC 2024 (in the center of the Flame Nebula) and the Orion Nebula Cluster, NASA’s Chandra X-ray Observatory teamed up with infrared telescopes to take a census of star ages. Conventional thinking suggests that stars closest to the center of a given star cluster should be the oldest and the youngest stars can be found around the edges. However, to their surprise, astronomers have discovered that the opposite is true: “Our findings are counterintuitive,” said Konstantin Getman of Penn State University, lead scientist of this new study. “It means we need to think harder and come up with more ideas of how stars like our sun are formed.”
59016843
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astroengine writes:
About 500 light-years away in the constellation Cygnus lives a star, which, though smaller and redder than the sun, has a planet that may look awfully familiar. With a diameter just 10 percent bigger than Earth’s, the newly found world is the first of its size found basking in the benign temperature region around a parent star where water, if it exists, could pool in liquid form. Scientists on the hunt for Earth's twin are focused on worlds that could support liquid surface water, which may be necessary to brew the chemistry of life. "Kepler-186f is significant because it is the first exoplanet that is the same temperature and the same size (well, ALMOST!) as the Earth,” David Charbonneau, with the Harvard-Smithsonian Center for Astrophysics, wrote in an email to Discovery News. "Previously, the exoplanet most like Earth was Kepler-62f, but Kepler-186f is significantly smaller. Now we can point to a star and say, ‘There lies an Earth-like planet.’”
