Space & Science discoveries

a59

a59

Well-Known Member


A new 1.3-billion-pixel image from NASA’s Mars rover Curiosity allows viewers to zoom in and investigate part of the Red Planet in incredible detail.

The huge mosaic stitches together nearly 900 photos that the Curiosity rover took with some of its 17 cameras during the robot's exploration of Gale Crater on Mars, NASA officials said.

"It gives a sense of place and really shows off the cameras' capabilities," Bob Deen, of the Multi-Mission Image Processing Laboratory at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "You can see the context and also zoom in to see very fine details."

The new image is the first NASA-produced view from the surface of Mars that's larger than 1 billion pixels, officials said. It's a full-circle scene centered on the site dubbed "Rocknest," where Curiosity gathered its first scoops of sandy soil for analysis. The 3.4-mile-high (5.5 kilometers) Mount Sharp looms in the distance.

You can access the full-resolution, zoomable image at: http://mars.nasa.gov/bp1/


Deen constructed the mosaic using 871 pictures from Curiosity's Mast Camera instrument and 25 black-and-white frames from the rover's navigation cameras. The photos were taken between Oct. 5 and Nov. 16, 2012, officials said.

Curiosity landed inside the 96-mile-wide (154 km) Gale Crater on Aug. 5, 2012, kicking off a planned two-year surface mission to assess Mars' past and present potential to host microbial life. In addition to its 17 cameras, Curiosity also carries 10 different science instruments to aid its quest.

The six-wheeled robot has already checked off its primary goal. Mission scientists announced in March that a spot near Curiosity's landing site called Yellowknife Bay was indeed habitable long ago.


The foothills of Mount Sharp, which lie about 5 miles (8 km) from Yellowknife Bay as the crow flies, have long been Curiosity's ultimate destination; mission scientists want to read the history of Mars' changing environmental conditions like a book as the rover climbs up the mountain's lower reaches.

Curiosity is wrapping up activities near its landing site and should be ready to start the roughly year-long journey to Mount Sharp in the coming days, mission team members have said.
 
  • Advertisement
  • a59

    a59

    Well-Known Member
    NASA-Led Study Explains Decades of Black Hole Observations

    A new study by astronomers at NASA, Johns Hopkins University and the Rochester Institute of Technology confirms long-held suspicions about how stellar-mass black holes produce their highest-energy light.

    "Our work traces the complex motions, particle interactions and turbulent magnetic fields in billion-degree gas on the threshold of a black hole, one of the most extreme physical environments in the universe," said lead researcher Jeremy Schnittman, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md.

    By analyzing a supercomputer simulation of gas flowing into a black hole, the team finds they can reproduce a range of important X-ray features long observed in active black holes.


    This animation of supercomputer data takes you to the inner zone of the accretion disk of a stellar-mass black hole. Gas heated to 20 million degrees Fahrenheit as it spirals toward the black hole glows in low-energy, or soft, X-rays. Just before the gas plunges to the center, its orbital motion is approaching the speed of light. X-rays up to hundreds of times more powerful ("harder") than those in the disk arise from the corona, a region of tenuous and much hotter gas around the disk. Coronal temperatures reach billions of degrees. The event horizon is the boundary where all trajectories, including those of light, must go inward. Nothing, not even light, can pass outward across the event horizon and escape the black hole.
    Credit: NASA's Goddard Space Flight Center
    Music: "Lost in Space" by Lars Leonhard, courtesy of the artist
    Gas falling toward a black hole initially orbits around it and then accumulates into a flattened disk. The gas stored in this disk gradually spirals inward and becomes greatly compressed and heated as it nears the center. Ultimately reaching temperatures up to 20 million degrees Fahrenheit (12 million C) -- some 2,000 times hotter than the sun's surface -- the gas shines brightly in low-energy, or soft, X-rays.

    For more than 40 years, however, observations have shown that black holes also produce considerable amounts of "hard" X-rays, light with energy tens to hundreds of times greater than soft X-rays. This higher-energy light implies the presence of correspondingly hotter gas, with temperatures reaching billions of degrees.

    The new study bridges the gap between theory and observation, demonstrating that both hard and soft X-rays inevitably arise from gas spiraling toward a black hole.

    Working with Julian Krolik, a professor at Johns Hopkins University in Baltimore, and Scott Noble, a research scientist at the Rochester Institute of Technology in Rochester, N.Y., Schnittman developed a process for modeling the inner region of a black hole's accretion disk, tracking the emission and movement of X-rays, and comparing the results to observations of real black holes.

    Noble developed a computer simulation solving all of the equations governing the complex motion of inflowing gas and its associated magnetic fields near an accreting black hole. The rising temperature, density and speed of the infalling gas dramatically amplify magnetic fields threading through the disk, which then exert additional influence on the gas.

    The result is a turbulent froth orbiting the black hole at speeds approaching the speed of light. The calculations simultaneously tracked the fluid, electrical and magnetic properties of the gas while also taking into account Einstein's theory of relativity.

    Running on the Ranger supercomputer at the Texas Advanced Computing Center located at the University of Texas in Austin, Noble's simulation used 960 of Ranger's nearly 63,000 central processing units and took 27 days to complete.

    Over the years, improved X-ray observations provided mounting evidence that hard X-rays originated in a hot, tenuous corona above the disk, a structure analogous to the hot corona that surrounds the sun.

    "Astronomers also expected that the disk supported strong magnetic fields and hoped that these fields might bubble up out of it, creating the corona," Noble explained. "But no one knew for sure if this really happened and, if it did, whether the X-rays produced would match what we observe."

    Using the data generated by Noble's simulation, Schnittman and Krolik developed tools to track how X-rays were emitted, absorbed, and scattered throughout both the accretion disk and the corona region. Combined, they demonstrate for the first time a direct connection between magnetic turbulence in the disk, the formation of a billion-degree corona, and the production of hard X-rays around an actively "feeding" black hole.

    A paper reporting the findings was published in the June 1 edition of The Astrophysical Journal.

    In the corona, electrons and other particles move at appreciable fractions of the speed of light. When a low-energy X-ray from the disk travels through this region, it may collide with one of the fast-moving particles. The impact greatly increases the X-ray's energy through a process known as inverse Compton scattering.

    "Black holes are truly exotic, with extraordinarily high temperatures, incredibly rapid motions and gravity exhibiting the full weirdness of general relativity," Krolik said. "But our calculations show we can understand a lot about them using only standard physics principles."

    The study was based on a non-rotating black hole. The researchers are extending the results to spinning black holes, where rotation pulls the inner edge of the disk further inward and conditions become even more extreme. They also plan a detailed comparison of their results to the wealth of X-ray observations now archived by NASA and other institutions.

    Black holes are the densest objects known. Stellar-mass black holes form when massive stars run out of fuel and collapse, crushing up to 20 times the sun's mass into compact objects less than 75 miles (120 kilometers) wide.
     
    Last edited by a moderator:
    a59

    a59

    Well-Known Member
    Found! 3 Super-Earth Planets That Could Support Alien Life

    The habitable zone of a nearby star is filled to the brim with planets that could support alien life, scientists announced today (June 25).

    An international team of scientists found a record-breaking three potentially habitable planets around the star Gliese 667C, a star 22 light-years from Earth that is orbited by at least six planets, and possibly as many as seven, researchers said. The three planet contenders for alien life are in the star's "habitable zone" — the temperature region around the star where liquid water could exist. Gliese 667C is part of a three-star system, so the planets could see three suns in their daytime skies.

    The three potentially rocky planets in Gliese 667C's habitable zone are known as super-Earths — exoplanets that are less massive than Neptune but more massive than Earth. Their orbits make them possible candidates for hosting life, officials from the European Southern Observatory said in a statement.


    "We knew that the star had three planets from previous studies, so we wanted to see whether there were any more," co-leader of the study Mikko Tuomi of the University of Hertfordshire, U.K. said in a statement. "By adding some new observations and revisiting existing data we were able to confirm these three and confidently reveal several more. Finding three low-mass planets in the star's habitable zone is very exciting!"

    This is the first time three low-mass planets have been spotted in the habitable zone of the same star system, and it's unlikely that astronomers will find any more around Gliese 667C. The star's habitable zone is packed full, making it impossible for another planet to orbit stably within the zone, the researchers said.

    "The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star — instead of looking at 10 stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them," team member Rory Barnes of the University of Washington said in a statement.


    Gliese 667C is the faintest star in the three-star system. From the surface of the planets in orbit around Gliese 667C, the two brighter stars would be as bright as the full moon by night and shine visibly during the day, ESO scientists said.

    Gliese 667C is cooler and dimmer than the sun, making it possible for planets that have very close-in orbits to remain habitable. This star's habitable zone lies within an orbit the size of Mercury's around the sun, ESO officials said.
     
    a59

    a59

    Well-Known Member
    60 Billion Alien Planets Could Support Life, Study Suggests


    Though only about dozen potentially habitable exoplanets have been detected so far, scientists say the universe should be teeming with alien worlds that could support life. The Milky Way alone may host 60 billion such planets around faint red dwarf stars, a new estimate suggests.

    Based on data from NASA's planet-hunting Kepler spacecraft, scientists have predicted that there should be one Earth-size planet in the habitable zone of each red dwarf, the most common type of star. But a group of researchers has now doubled that estimate after considering how cloud cover might help an alien planet support life.

    "Clouds cause warming, and they cause cooling on Earth," study researcher Dorian Abbot, an assistant professor in geophysical sciences at the University of Chicago, said in a statement. "They reflect sunlight to cool things off, and they absorb infrared radiation from the surface to make a greenhouse effect. That's part of what keeps the planet warm enough to sustain life." [9 Alien Planets That Could Support Life]


    The habitable zone is defined as the region where a planet has the right temperature to keep liquid water on its surface, thought to be a requirement for life as we know it. If a planet is too far from its star, its water freezes; too close, water vaporizes. Since red dwarfs are dimmer and cooler than our sun, their habitable zone is much cozier than our solar system's.

    "If you're orbiting around a low-mass or dwarf star, you have to orbit about once a month, once every two months to receive the same amount of sunlight that we receive from the sun," explained another study author, Nicolas Cowan, a postdoctoral fellow at Northwestern University.

    With such a snug orbit, a habitable planet around a red dwarf would become tidally locked, meaning it would always have one side facing its star, much like the moon faces Earth. This side would see eternal daylight.

    In the new study, the researchers used 3D simulations to model the way air and moisture would move over a planet tidally locked around a red dwarf. The team found that any surface water would result in water clouds. What's more, highly reflective clouds would build at the point of the star-facing side where it's always high noon. This would have a cooling effect in the inner ring of the habitable zone, meaning the planets there would be able to sustain water on their surfaces much closer to their star, the researchers say.

    The findings could give scientists a new way to confirm the presence of liquid water on the surface of alien planets with the James Webb Space Telescope (JWST), a new space-based observatory scheduled for launch in 2018, the researchers say.

    "If you look at Brazil or Indonesia with an infrared telescope from space, it can look cold, and that's because you're seeing the cloud deck," Cowan said. "The cloud deck is at high altitude, and it's extremely cold up there."

    The same could be true of a habitable exoplanet with a highly reflective cloud cover, the researchers say. If JWST detects a similar cold signal over the dayside of an alien world, Abbot said, "it's almost definitely from clouds, and it's a confirmation that you do have surface liquid water."

    The research was detailed June 27 in the journal Astrophysical Journal Letters.


    Kepler-62e and f: Possibly Life-Supporting 'Water Worlds'
    Kepler-62e and 62f are perhaps the most promising life-hosting candidates yet found beyond our solar system. The planets, which are 1.6 and 1.4 times the size of Earth, respectively, may both be water worlds whose global oceans are teeming with life, researchers say. Their discovery was announced in April 2013.
     
    a59

    a59

    Well-Known Member
    NASA's Next Mars Rover Will Search for Signs of Life





    NASA's next Mars rover should hunt for signs of past Red Planet life and collect samples for eventual return to Earth, a team of mission planners has determined.

    The new Mars rover — slated to launch in 2020 — should explore a site that once was habitable, make its own observations and snag material for scientists here on Earth to study in unprecedented detail at some point in the future, according to a new report compiled by the mission's "science definition team" (SDT).

    "The SDT-preferred mission concept employs new in situ scientific instrumentation in order to seek signs of past life (had it been there), select and store a compelling suite of samples in a returnable cache and demonstrate technology for future robotic and human exploration of Mars," states the report, which was released to the public today (July 9). [NASA's 2020 Mars Rover (Images)]

    The 2020 Mars rover will be based heavily on NASA's Curiosity rover, which touched down last August on a mission to determine if Mars could ever have supported microbial life.

    For example, the new robot will use a similar chassis and "sky crane" landing system, NASA officials have said. But the 2020 rover will take the science to a whole new level.

    "The 2020 rover as proposed by the Science Definition Team would carry a different and more advanced set of science instruments than Curiosity carries, its drill would extract cores rather than blended powder from rocks and it would collect and package samples for possible future return to Earth," NASA officials wrote today in an FAQ about the SDT's report.


    Just what those instruments will be is unclear at the moment; they will be selected through a competitive process. But the science gear will search for visual, mineralogical and chemical signs of past life if the SDT recommendations are adopted.

    "The capability for examining the mineralogic composition of samples at microscopic scale would be unprecedented for a mission to Mars," NASA officials wrote in the FAQ. "The search for potential signs of past life could use assessments of textures, shapes, mineralogy, organic-matter content, and possibly elemental chemistry at the scale of individual grains within a sample."

    The rover would also gather and store samples for potential return to Earth by a future mission (the timing and details of which are yet to be determined). Sample-return is viewed by most scientists as the best way to look for signs of Red Planet life.

    The new rover's landing site has not been selected yet, officials said, and its power source similarly has not been confirmed.

    Curiosity is powered by a radioisotope thermoelectric generator (RTG), which converts the heat generated by radioactive decay into electricity. The 2020 rover may follow suit, but it's also possible that it could run on solar power, like NASA's smaller Spirit and Opportunity rovers, which landed on Mars in 2004.

    "No final decision on a power source for the 2020 rover would be made until the mission completes a review through the National Environmental Policy Act process, which considers the environmental impacts of launching and conducting the mission," NASA officials wrote in the FAQ.

    Curiosity's mission cost a total of $2.5 billion. The 2020 rover is expected to be significantly cheaper, with a total price tag estimated at around $1.5 billion.

    The new 2020 rover mission was announced this past December, and the SDT was formed in January.
     
    a59

    a59

    Well-Known Member
    Milky Way Magic Captured Over Rural Maine (Photos)




    A veteran astrophotographer in Maine took advantage of a clear night sky in rural Maine to capture two beautiful images of our host galaxy, the Milky Way.

    "Living in rural Maine offers me some great opportunities to capture the beauty of our night sky with mostly very little light pollution. This spot at the top of a ridge in the small town of Palermo is a great example," photographer Mike Taylor wrote SPACE.com in an email. "On this particular night there was quite a show of green airglow in the sky and a just a bit of yellow/orange glow from nearby towns on the horizon."

    The first photo is a single image capture, while the second image is a composite of 81 frames from a static time lapse of the Milky Way Galaxy in the night sky. Taylor stacked the frames of this sequence to make a standard star trails image and then blended/masked in a single frame of the Milky Way. The processing was done with Lightroom 4 and Photoshop CS5. He used a Nikon D7000 camera, Tokina 11-16mm at 11mm, f/2.8, 25 seconds, ISO 1600 on June 10, 2013 to capture the images.

    Our host galaxy, the Milky Way, is a barred spiral galaxy seen as a band of light in the night sky. It stretches between 100, 000 and 120,000 light-years in diameter. It is estimated that the galaxy has approximately 400 billion stars. At the center of our galaxy lies a gigantic black hole billions of times the size of the sun.
     
    a59

    a59

    Well-Known Member
    Hubble researchers identify color of an exoplanet for the first time



    While exoplanets are seemingly a dime a dozen, their looks have been mysteries; they often exist only as measurements. Scientists using the Hubble Space Telescope have partly solved that riddle by pinpointing the visible color of an extrasolar world for the first time. By measuring reflected light, they can tell that HD 189733b (conceptualized above) is a cobalt blue, much like Earth's oceans. Not that we can claim much kinship, though. The planet is a gas giant 63 light-years away -- its blue tint comes from an atmosphere likely full of deadly silicate. As disappointing as that may be, the discovery should at least help us understand planet types that don't exist in the Solar System.
     
    Dynamite Joe

    Dynamite Joe

    Well-Known Member
    First Experimental Signs of a New Physics Beyond the Standard Model​

    Jul 31, 2013



    The Standard Model, which has given the most complete explanation up to now of the universe, has gaps, and is unable to explain phenomena like dark matter or gravitational interaction between particles. Physicists are therefore seeking a more fundamental theory that they call "New Physics," but up to now there has been no direct proof of its existence, only indirect observation of dark matter, as deduced, among other things, from the movement of the galaxies.

    A team of physicists formed by the professor of Physics at Universitat Autònoma de Barcelona (UAB) Joaquim Matias, Javier Virto, postdoctoral researcher at the same university, and Sebastien Descotes Genon, from the Centre National de la Recherche Scientifique (CNRS) / Université Paris-Sud, has predicted that New Physics would imply the existence of deviations in the probability of a very specific decay of a particle, the B meson. Detecting these small deviations through an experiment would be the first direct proof of the existence of this fundamental theory.

    On 19 July of this year, at the EPS 2013 international conference on particle physics in Stockholm, scientists at the LHCb detector, one of the large experiments being conducted by the CERN's LHC accelerator, presented the results of the experimental measurements of the B meson decay. The measurements showed deviations with respect to the predictions of the Standard Model that were previously calculated by UAB and CNRS researchers. The team of scientists have demonstrated that all these deviations show a coherent pattern and that has allowed them to identify their origin from a unique source.

    The results of their analysis point to a deviation from the Standard Model prediction of 4.5 sigmas. If confirmed, this is a major event, since scientists regard 3 sigmas as "scientific proof" of New Physics and 5 sigmas as a "discovery."

    "We must be prudent, because more studies and more experimental measurements will be needed for confirmation," explains Joaquim Matias, "but if they are confirmed this is the first direct proof of New Physics, a more general theory than the current Standard Model." "If the Higgs completed the Standard Model puzzle, these findings could be the first piece in an even bigger puzzle, adds Dr Matias.

    The researchers claim that one of the New Physics models that could explain these results would be the one that postulates the existence of a new particle named Zprima, "but there could be lots of compatible models," points out Dr Matias.

    The findings are so interesting that scientists at the other main LHC experiment, the CMS detector, want to take these measurements. The CMS has invited Dr. Matias to explain the theoretical details in a seminar to see it the results can be corroborated. At the same time, LHCb is also adding new data to improve the statistics and confirm the measurements next March.

    Also participating in the study were Javier Virto, from the UAB's Department of Physics, and Sebastien Descotes-Genon from the University of Paris-Sud 11.

    Beyond the Standard Model

    For years, particle physicists have known that the theory they use, the Standard Model, despite being a very successful model in all tests carried out so far, has significant deficiencies such as lack of a candidate for dark matter. In addition, it has other problems such as the so-called fundamental problem of hierarchies or the matter-antimatter asymmetry of the universe.

    Two of the central goals of the Large Hadron Collider (LHC) at CERN (Geneva) are finding the Higgs boson and finding what is called New Physics, a more fundamental and general theory than that of the Standard Model in which the latter would be just one particular case. Just a year ago, the Higgs boson was discovered, but the particle seems to fit perfectly into the Standard Model and currently gives us no clues regarding New Physics.

    At CERN there are four experiments, four large detectors (ATLAS, CMS, LHCb, and Alice) that record collisions between particles so that scientists can study their behaviour. The LHCb detector is designed to study the behaviour of quarks and what are known as rare decays, which are very infrequent.

    On 19 July of this year, at EPS 2013, the European Physics Society's International Conference on Particle Physics, in Stockholm, Dr. Matias presented the theoretical predictions of his research team on one of these decays: that of a B meson, formed by a b quark and a d antiquark, into a pair of muons and a particle called K*. The UAB and CNRS researchers calculated and predicted how this decay should work and how it should change in different New Physics scenarios.

    Shortly afterwards, an experimental physicist from the LHCb detector, Nicola Serra, presented at the same conference the first completed experimental results of that decay. Surprisingly, the experimental measurements were consistent with the deviations predicted by Joaquim Matias and his collaborators. For the first time, deviations of this type were consistent with theoretical predictions based on the presence of contributions that transcends the Standard Model.

    Source
     
    a59

    a59

    Well-Known Member
    Asteroid Will Buzz Earth This Week Inside the Moon's Orbit


    A tiny asteroid discovered just last week is set to zip by Earth on Wednesday (Sept. 18), passing between our planet and the moon. It is small enough and distant enough that it poses no threat to people, scientists say.

    Astronomers first observed the space rock, named 2013 RZ53, on Friday (Sept. 13), according to data from the Minor Planet Center, a clearinghouse of information on comets and asteroids based in Cambridge, Mass.

    The asteroid measures only 3 to 10 feet (1 to 3 meters) across, and it is expected to pass at a safe distance of more than 148,000 miles (230,800 kilometers) away from Earth when it makes its closest approach on Wednesday at 6:20 p.m. EDT (22:20 GMT). (The moon orbits Earth at an average distance of 239,000 miles, or 384,600 km.)

    Even if it were aimed directly at our planet, the newly discovered space rock is so small that it would likely burn up in the atmosphere before it could hit the ground.

    By observing the asteroid over several days, researchers pieced together its trajectory. They also put together an animation of asteroid 2013 RZ53's path, showing that it comes relatively close to Earth's orbit.

    The space rock belongs to the Apollo family of near-Earth asteroids — the same group from which the meteor that exploded over the Russian city of Chelyabinsk in February 2013 is thought to have originated. The Russian meteor was much larger than the newly discovered asteroid, estimated to have been about 56 to 66 feet wide (17 to 20 m) before it exploded.

    The discovery of 2013 RZ53 was made by researchers with the Mount Lemmon Survey at the University of Arizona. The project is part of a larger, NASA-sponsored program called the Catalina Sky Survey, which scans the cosmos for potentially dangerous asteroids.

    NASA and its partners keep tabs on asteroids and comets that fly near the planet as part of the Near-Earth Object Observations program, which uses a network of ground-based and space telescopes to monitor potential threats.
     
    Dynamite Joe

    Dynamite Joe

    Well-Known Member
    How Common Are Habitable Planets? One in Five Sun-Like Stars May Have Earth-Size, Potentially Habitable Planets



    Nov. 4, 2013 — NASA's Kepler space telescope, now crippled and its four-year mission at an end, nevertheless provided enough data to answer its main research question: How many of the 200 billion stars in our galaxy have potentially habitable planets?

    Based on a statistical analysis of all the Kepler observations, University of California, Berkeley, and University of Hawaii, Manoa, astronomers now estimate that one in five stars like the sun have planets about the size of Earth and a surface temperature conducive to life.

    Given that about 20 percent of stars are sun-like, the researchers say, that amounts to several tens of billions of potentially habitable, Earth-size planets in the Milky Way Galaxy.

    "When you look up at the thousands of stars in the night sky, the nearest sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye. That is amazing," said UC Berkeley graduate student Erik Petigura, who led the analysis of the Kepler data.

    "It's been nearly 20 years since the discovery of the first extrasolar planet around a normal star. Since then, we have learned that most stars have planets of some size orbiting them, and that Earth-size planets are relatively common in close-in orbits that are too hot for life," said Andrew Howard, a former UC Berkeley post-doctoral fellow who is now on the faculty of the Institute for Astronomy at the University of Hawaii. "With this result, we've come home, in a sense, by showing that planets like our Earth are relatively common throughout the Milky Way Galaxy."

    Petigura, Howard and Geoffrey Marcy, UC Berkeley professor of astronomy, will publish their analysis and findings this week in the online early edition of the journal Proceedings of the National Academy of Sciences.

    Earth-size may not mean habitable

    "For NASA, this discovery is really important, because future missions will try to take an actual picture of a planet, and the size of the telescope they have to build depends on how close the nearest Earth-size planets are," Howard said. "An abundance of planets orbiting nearby stars simplifies such follow-up missions."

    The team cautioned that Earth-size planets in orbits about the size of Earth's are not necessarily hospitable to life, even if they reside in the habitable zone around a star where the temperature is not too hot and not too cold.

    "Some may have thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive. Others may have rocky surfaces that could harbor liquid water suitable for living organisms," Marcy said. "We don't know what range of planet types and their environments are suitable for life."

    Last week, however, Howard, Marcy and their colleagues provided hope that many such planets actually are rocky and could support liquid water. They reported that one Earth-size planet discovered by Kepler -- albeit, a planet with a likely temperature of 2,000 Kelvin, which is far too hot for life as we know it -- is the same density as Earth and most likely composed of rock and iron, like Earth.

    "This gives us some confidence that when we look out into the habitable zone, the planets Erik is describing may be Earth-size, rocky planets," Howard said.

    Transiting planets

    NASA launched the Kepler space telescope in 2009 to look for planets outside the solar system that cross in front of, or transit, their stars, which causes a slight diminution -- about one hundredth of 1 percent -- in the star's brightness. From among the 150,000 stars photographed every 30 minutes for four years, NASA's Kepler team reported more than 3,000 planet candidates. Many of these are much larger than Earth -- ranging from large planets with thick atmospheres, like Neptune, to gas giants like Jupiter -- or in orbits so close to their stars that they are roasted.

    To sort them out, Petigura and his colleagues are using the Keck telescopes in Hawaii to obtain spectra of as many stars as possible. This will help them determine each star's true brightness and calculate the diameter of each transiting planet, with an emphasis on Earth-diameter planets.

    Independently, Petigura, Howard and Marcy focused on the 42,000 stars that are like the sun or slightly cooler and smaller, and found 603 candidate planets orbiting them. Only 10 of these were Earth-size, that is, one to two times the diameter of Earth and orbiting their star at a distance where they are heated to lukewarm temperatures suitable for life. The team's definition of habitable is that a planet receives between four times and one-quarter the amount of light that Earth receives from the sun.

    A census of extrasolar planets

    What distinguishes the team's analysis from previous analyses of Kepler data is that they subjected Petigura's planet-finding algorithms to a battery of tests in order to measure how many habitable zone, Earth-size planets they missed. Petigura actually introduced fake planets into the Kepler data in order to determine which ones his software could detect and which it couldn't.

    "What we're doing is taking a census of extrasolar planets, but we can't knock on every door. Only after injecting these fake planets and measuring how many we actually found could we really pin down the number of real planets that we missed," Petigura said.

    Accounting for missed planets, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, allowed them to estimate that 22 percent of all sun-like stars in the galaxy have Earth-size planets in their habitable zones.

    "The primary goal of the Kepler mission was to answer the question, 'When you look up in the night sky, what fraction of the stars that you see have Earth-size planets at lukewarm temperatures so that water would not be frozen into ice or vaporized into steam, but remain a liquid, because liquid water is now understood to be the prerequisite for life?'" Marcy said. "Until now, no one knew exactly how common potentially habitable planets were around sun-like stars in the galaxy."

    All of the potentially habitable planets found in the team's survey are around K stars, which are cooler and slightly smaller than the sun, Petigura said. But the researchers' analysis shows that the result for K stars can be extrapolated to G stars like the sun. Had Kepler survived for an extended mission, it would have obtained enough data to directly detect a handful of Earth-size planets in the habitable zones of G-type stars.

    "If the stars in the Kepler field are representative of stars in the solar neighborhood, … then the nearest (Earth-size) planet is expected to orbit a star that is less than 12 light-years from Earth and can be seen by the unaided eye," the researchers wrote in their paper. "Future instrumentation to image and take spectra of these Earths need only observe a few dozen nearby stars to detect a sample of Earth-size planets residing in the habitable zones of their host stars."

    In January, the team reported a similar analysis of Kepler data for scorched planets that orbit close to their stars. The new, more complete analysis shows that "nature makes about as many planets in hospitable orbits as in close-in orbits," Howard said.

    The research was funded by UC Berkeley and the National Science Foundation, with the assistance of the W. M. Keck Observatory and NASA.

    Source
    http://newscenter.berkeley.edu/2013...ey-question-how-common-are-habitable-planets/
     
    Dynamite Joe

    Dynamite Joe

    Well-Known Member
    Fast, Furious, Refined: Smaller Black Holes Can Eat Plenty



    Figure 1. Artist’s visualization of the environment around M101 ULX-1, showing a stellar-mass black hole (foreground) with accretion disk. Gas from the Wolf-Rayet star (background) feeds the black hole’s voracious appetite. Gemini Observatory/AURA artwork by Lynette Cook.



    Figure 2. ULX-1 is located near a spiral arm of M101. The image for M101 is composed from X-ray (Chandra X-ray Observatory; Purple), Infrared (Spitzer Satellite; Red), Optical (Hubble Space Telescope; Yellow) and Ultraviolet (GALEX satellite; Blue).Credit: Chandra X-ray Observatory, Spitzer Satellite, Hubble Space Telescope, and GALEX Satellite.

    "It has elegant manners," says research team member Stephen Justham, of the National Astronomical Observatories of China, Chinese Academy of Sciences. Such lightweights, he explains, must devour matter at close to their theoretical limits of consumption to sustain the kind of energy output observed. "We thought that when small black holes were pushed to these limits, they would not be able to maintain such refined ways of consuming matter," Justham explains. "We expected them to display more complicated behavior when eating so quickly. Apparently we were wrong."

    A Surprising Twist

    X-ray sources give off high- and low-energy X-rays, which astronomers call hard and soft X-rays, respectively. In what might seem like a contradiction, larger black holes tend to produce more soft X-rays, while smaller black holes tend to produce relatively more hard X-rays. This source, called M101 ULX-1, is dominated by soft X-rays, so researchers expected to find a larger black hole as its energy source.

    In a surprising twist, however, the new observations made at the Gemini Observatory, and published in the November 28th issue of the journal Nature, indicate that M101 ULX-1's black hole is on the small side, and astrophysicists don't understand why.

    In theoretical models of how matter falls into black holes and radiates energy, the soft X-rays come primarily from the accretion disk (see illustration), while hard X-rays are typically generated by a high-energy "corona" around the disk. The models show that the corona's emission strength should increase as the rate of accretion gets closer to the theoretical limit of consumption. Interactions between the disk and corona are also expected to become more complex.

    Based on the size of the black hole found in this work, the region around M101-ULX-1 should, theoretically, be dominated by hard X-rays and appear structurally more complicated. However, that isn't the case.

    "Theories have been suggested which allow such low-mass black holes to eat this quickly and shine this brightly in X-rays. But those mechanisms leave signatures in the emitted X-ray spectrum, which this system does not display," says lead author Jifeng Liu, of the National Astronomical Observatories of China, Chinese Academy of Sciences. "Somehow this black hole, with a mass only 20-30 times the mass of our Sun, is able to eat at a rate near to its theoretical maximum while remaining relatively placid. It's amazing. Theory now needs to somehow explain what's going on."

    An Intermediate-mass Black Hole Dilemma

    The discovery also delivers a blow to astronomers hoping to find conclusive evidence for an "intermediate-mass" black hole in M101 ULX-1. Such black holes would have masses roughly between 100 and 1000 times the mass of the Sun, placing them between normal stellar-mass black holes and the monstrous supermassive black holes that reside in the centers of galaxies. So far these objects have been frustratingly elusive, with potential candidates but no broadly-accepted detection. Ultra-luminous X-ray sources (ULXs) have been one of the main proposed hiding places for intermediate-mass black holes, and M101 ULX-1 was one of the most promising-looking contenders.

    "Astronomers hoping to study these objects will now have to focus on other locations for which indirect evidence of this class of black holes has been suggested, either in the even brighter 'hyper-luminous' X-ray sources or inside some dense clusters of stars," explains research team member Joel Bregman of the University of Michigan.

    "Many scientists thought it was just a matter of time until we had evidence for an intermediate-mass black hole in M101 ULX-1," says Liu. But the new Gemini findings both take away some of that hope to solve an old puzzle and adds the fresh mystery of how this stellar-mass black hole can consume matter so calmly.

    To determine the mass of the black hole, the researchers used the Gemini Multi-Object Spectrograph at the Gemini North telescope on Mauna Kea, Hawai'i to measure the motion of the companion. This star, which feeds matter to the black hole, is of the Wolf-Rayet variety. Such stars emit strong stellar winds, from which the black hole can then draw in material. This study also revealed that the black hole in M101 ULX-1 can capture more material from that stellar wind than astronomers had anticipated.

    M101 ULX-1 is ultra-luminous, shining a million times more brightly than the Sun in both X-rays (from the black hole accretion disk) and in the ultraviolet (from the companion star). Co-author Paul Crowther from the University of Sheffield in the United Kingdom adds, "Although this isn't the first Wolf-Rayet black hole binary ever discovered, at some 22 million light-years away, it does set a new distance record for such a system. The Wolf-Rayet star will have died in a small fraction of the time it has taken for light to reach us, so this system is now likely a double black hole binary."

    "Studying objects like M101 ULX-1 in distant galaxies gives us a vastly larger sampling of the diversity of objects in our universe," says Bregman. "It's absolutely amazing that we have the technology to observe a star orbiting a black hole in another galaxy this far away."

    Source
    http://www.gemini.edu/node/12100
     
    My Moria Moon

    My Moria Moon

    Legendary Member
    Orange Room Supporter
    When I was fifteen, on delightful warm nights, I used to look up at the stars and dream of that mother of all telescopes, one that is portable, pocket size and with a camera, and which would allow me to zoom in on any object in space up to the highest possible resolution of its surface, as to spot an alien worm crawling..

    Wouldn't it be very practical to have everyone being able to scan the universe from one's balcony and post their discoveries on Youtube or Instagram? I wonder what would a salafi do with his heavy earthy burden when he discovers some deep space creatures look just like him, but eat sand instead and breathe the fumes of sulfuric acid?

    There's hope, I guess, I'm sure someone had the same dream about the iPhone and the iPad. :disli:
     
    EuroMode

    EuroMode

    Active Member
    Alien planet 11 times bigger than Jupiter found in bizarre, massive orbit



    An enormous alien planet — one that is 11 times more massive than Jupiter — was discovered in the most distant orbit yet found around a single parent star.

    The newfound exoplanet, dubbed HD 106906 b, dwarfs any planetary body in the solar system, and circles its star at a distance that is 650 times the average distance between the Earth and the sun. The existence of such a massive and distantly orbiting planet raises new questions about how these bizarre worlds are formed, the researchers said.

    "This system is especially fascinating because no model of either planet or star formation fully explains what we see," study lead researcher Vanessa Bailey, a fifth-year graduate student in the University of Arizona's department of astronomy, said in a statement. [The Strangest Alien Planets (Gallery)]

    In the most commonly accepted theories of planet formation, it is thought that planets that orbit close to their parent star, such as Earth, began as small, asteroid-type bodies that clumped together in the primordial disk of gas and dust around the burgeoning star. Yet, this process operates too slowly to explain how giant planets form far away from their star, the researcher said.

    Alternative hypotheses have suggested that distant giant planets may form in ways similar to mini binary star systems, Bailey said.

    "A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit," she explained.

    In the HD 106906 system, the star and planet may have collapsed independently, but the materials that clumped together to form the planet were insufficient for it to grow large enough to ignite into a new star, Bailey said.

    But, there are still problems with this scenario. For one, difference between the masses of two stars in a binary system is typically no more than a ratio of 10 to 1.

    "In our case, the mass ratio is more than 100-to-1," Bailey said. "This extreme mass ratio is not predicted from binary star formation theories — just like planet formation theory predicts that we cannot form planets so far from the host star."

    Researchers are also keen to study the new planet, because leftover material from when the planet and star formed can still be detected.

    "Systems like this one, where we have additional information about the environment in which the planet resides, have the potential to help us disentangle the various formation models," Bailey said. "Future observations of the planet's orbital motion and the primary star's debris disk may help answer that question."

    "The planet HD 106906 b is only 13 million years old, and is still glowing from the residual heat from its formation," the researchers said. By comparison, Earth formed 4.5 billion years ago, which makes it roughly 350 times older than the newfound exoplanet.

    The planet was found using a thermal infrared camera mounted on the Magellan telescope in the Atacama Desert in Chile. The researchers used data from the Hubble Space Telescope to confirm their discovery.

    The study, which has been accepted for publication in a future issue of The Astrophysical Journal Letters, could lead to a better understanding of distantly orbiting exoplanets.

    "Every new directly detected planet pushes our understanding of how and where planets can form," study co-investigator Tiffany Meshkat, a graduate student at Leiden Observatory in the Netherlands, said in a statement. "Discoveries like HD 106906 b provide us with a deeper understanding of the diversity of other planetary systems."

    source foxnews
     
    EuroMode

    EuroMode

    Active Member
    New research raises hopes of finding alien life on Jupiter's icy moon Europa



    One of the moons of Jupiter may be another habitable part of the Solar System according to new research showing that Europa is rich in vital minerals and has spectacular water fountains spraying from a subsurface ocean.

    The Hubble Space Telescope has identified two huge plumes of water as high as 200km (124 miles) which occasionally erupt on Europa, while a separate study has found clay-like minerals littered around the moon’s frozen surface.

    The water fountain appears at certain moments in the orbit of Europa around Jupiter, suggesting it is powered by immense tidal forces that periodically increase the pressure within a subsurface ocean, causing it to erupt through cracks in the surface ice, according an analysis of Hubble data published in the journal Science.

    Europa is one of the more significant of Jupiter’s 63 known moons and astronomers believe that below is ice-covered surface is an ocean kept liquid by the heat of tidal forces. Some scientists have suggested that life may exist within this ocean, living off minerals and using tidal heat as a source of energy.

    A separate study based on a new analysis of data from Nasa Galileo mission detected important clay-like minerals on the surface of Europa which could have come from past collisions with asteroids or comets.

    Jim Shirley of Nasa’s Jet Propulsion Laboratory in Pasadena, California, said: “Organic materials, which are important building blocks for life, are often found in comets and primitive asteroids. Finding the rocky residues of this comet crash on Europa’s surface may open up a new chapter in the story of the search for life on Europa.”

    Many scientists believe that Europa may be the best place in the Solar System to find existing life as its ocean is in contact with rock and the icy surface is mixing with the ocean below, creating an energy gradient and a source of heat as the moon get progressively stretched and squeezed by gravity during its orbit around Jupiter.

    source independent
     
    EuroMode

    EuroMode

    Active Member
    Here's The 'Jade Rabbit' Rover That China Just Landed On The Moon

    Today China joined the United States and the former Soviet Union in managing to land an unmanned spacecraft on the moon. It was the first "soft-landing" since 1976,

    Here's a look at the "Jade Rabbit" rover that landed on the Bay of Rainbows at 9:12 p.m. local time and its mission:



    source businessinsider
     
    My Moria Moon

    My Moria Moon

    Legendary Member
    Orange Room Supporter
    Simulations back up theory that Universe is a hologram
    A ten-dimensional theory of gravity makes the same predictions as standard quantum physics in fewer dimensions.

    Ron Cowen
    10 December 2013


    At a black hole, Albert Einstein's theory of gravity apparently clashes with quantum physics, but that conflict could be solved if the Universe were a holographic projection.


    A team of physicists has provided some of the clearest evidence yet that our Universe could be just one big projection.

    In 1997, theoretical physicist Juan Maldacena proposed that an audacious model of the Universe in which gravity arises from infinitesimally thin, vibrating strings could be reinterpreted in terms of well-established physics. The mathematically intricate world of strings, which exist in nine dimensions of space plus one of time, would be merely a hologram: the real action would play out in a simpler, flatter cosmos where there is no gravity.

    Maldacena's idea thrilled physicists because it offered a way to put the popular but still unproven theory of strings on solid footing — and because it solved apparent inconsistencies between quantum physics and Einstein's theory of gravity. It provided physicists with a mathematical Rosetta stone, a 'duality', that allowed them to translate back and forth between the two languages, and solve problems in one model that seemed intractable in the other and vice versa. But although the validity of Maldacena's ideas has pretty much been taken for granted ever since, a rigorous proof has been elusive.

    In two papers posted on the arXiv repository, Yoshifumi Hyakutake of Ibaraki University in Japan and his colleagues now provide, if not an actual proof, at least compelling evidence that Maldacena’s conjecture is true.

    In one paper, Hyakutake computes the internal energy of a black hole, the position of its event horizon (the boundary between the black hole and the rest of the Universe), its entropy and other properties based on the predictions of string theory as well as the effects of so-called virtual particles that continuously pop into and out of existence. In the other, he and his collaborators calculate the internal energy of the corresponding lower-dimensional cosmos with no gravity. The two computer calculations match.

    “It seems to be a correct computation,” says Maldacena, who is now at the Institute for Advanced Study in Princeton, New Jersey and who did not contribute to the team's work.

    The findings “are an interesting way to test many ideas in quantum gravity and string theory”, Maldacena adds. The two papers, he notes, are the culmination of a series of articles contributed by the Japanese team over the past few years. “The whole sequence of papers is very nice because it tests the dual [nature of the universes] in regimes where there are no analytic tests.”

    “They have numerically confirmed, perhaps for the first time, something we were fairly sure had to be true, but was still a conjecture — namely that the thermodynamics of certain black holes can be reproduced from a lower-dimensional universe,” says Leonard Susskind, a theoretical physicist at Stanford University in California who was among the first theoreticians to explore the idea of holographic universes.

    Neither of the model universes explored by the Japanese team resembles our own, Maldacena notes. The cosmos with a black hole has ten dimensions, with eight of them forming an eight-dimensional sphere. The lower-dimensional, gravity-free one has but a single dimension, and its menagerie of quantum particles resembles a group of idealized springs, or harmonic oscillators, attached to one another.

    Nevertheless, says Maldacena, the numerical proof that these two seemingly disparate worlds are actually identical gives hope that the gravitational properties of our Universe can one day be explained by a simpler cosmos purely in terms of quantum theory.

    Nature doi:10.1038/nature.2013.14328
     
    Silence

    Silence

    Well-Known Member
    Orange Room Supporter
    At a black hole, Albert Einstein's theory of gravity apparently clashes with quantum physics, but that conflict could be solved if the Universe were a holographic projection.


    A team of physicists has provided some of the clearest evidence yet that our Universe could be just one big projection.
    So after all Plato got it right, 2500 years ago.
     
    LebReporter

    LebReporter

    Well-Known Member
    'Hand of God' spotted by NASA space telescope



    Religion and astronomy may not overlap often, but a new NASA X-ray image captures a celestial object that resembles the "Hand of God."

    The cosmic "hand of God" photo was produced when a star exploded and ejected an enormous cloud of material, which NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, glimpsed in high-energy X-rays, shown in blue in the photo. NASA's Chandra X-ray Observatory had imaged the green and red parts previously, using lower-energy X-rays.

    "NuSTAR's unique viewpoint, in seeing the highest-energy X-rays, is showing us well-studied objects and regions in a whole new light," NuSTAR telescope principal investigator Fiona Harrison, of the California Institute of Technology in Pasadena, said in a statement.

    The new image depicts a pulsar wind nebula, produced by the dense remnant of a star that exploded in a supernova. What's left behind is a pulsar, called PSR B1509-58 (B1509 for short), which spins around 7 times per second blowing a wind of particles into material ejected during the star's death throes.

    As these particles interact with nearby magnetic fields, they produce an X-ray glow in the shape of a hand. (The pulsar is located near the bright white spot in the image but cannot be seen itself, NASA officials said.)

    Scientists aren't sure whether the ejected material actually assumes the shape of a hand, or whether its interaction with the pulsar's particles is just making it appear that way.

    "We don't know if the hand shape is an optical illusion," Hongjun An, of McGill University in Montreal, said in a statement. "With NuSTAR, the hand looks more like a fist, which is giving us some clues."

    The red cloud appearing at the fingertips is a separate structure called RCW 89. The pulsar's wind may be heating the cloud to produce the low-energy X-ray glow, astronomers believe.

    The X-ray energies seen by NuSTAR range from 7 to 25 kiloelectron volts, or keV, whereas the energies seen by Chandra range from 0.5 to 2 keV.

    The Hand of God is an example of pareidolia, the psychological phenomenon of perceiving familiar shapes in random or vague images. Other common forms of pareidolia include seeing animals or faces in clouds, or the man in the moon. Despite its supernatural appearance, the Hand of God was produced by natural astrophysical phenomena.

    nbcnews
     
    EuroMode

    EuroMode

    Active Member
    Nasa says Mars mystery rock that ‘appeared’ from nowhere is ‘like nothing we’ve ever seen before’





    A mysterious rock which appeared in front of the Opportunity rover is “like nothing we’ve ever seen before”, according to Mars exploration scientists at Nasa.

    Experts said they were “completely confused” by both the origins and makeup of the object, which is currently being investigated by Opportunity’s various measuring instruments.

    Astronomers noticed the new rock had “appeared” without any explanation on an outcrop which had been empty just days earlier. The rover has been stuck photographing the same region of Mars for more than a month due to bad weather, with scientists at the Jet Propulsion Laboratory (JPL) in California monitoring the images it sends.

    Nasa issued a Mars status report entitled “encountering a surprise”, and lead Mars Exploration rover scientist Steve Squyres told a JPL event it seems the planet literally “keeps throwing new things at us”.

    He said the images, from 12 Martian days apart, were from no more than a couple of weeks ago. “We saw this rock just sitting here. It looks white around the edge in the middle and there’s a low spot in the centre that’s dark red – it looks like a jelly doughnut.

    “And it appeared, just plain appeared at that spot – and we haven’t ever driven over that spot.”



    Squyres said his team had two theories on how the rock got there – that there’s “a smoking hole in the ground somewhere nearby” and it was caused by a meteor, or that it was “somehow flicked out of the ground by a wheel” as the rover went by.

    “We had driven a metre or two away from here, and I think the idea that somehow we mysteriously flicked it with a wheel is the best explanation,” Squyres said.

    Yet the story got even stranger when Opportunity investigated further. Squyres explained: “We are as we speak situated with the rover’s instruments deployed making measurements of this rock.

    “We’ve taken pictures of both the doughnut and jelly parts, and the got the first data on the composition of the jelly yesterday.

    “It’s like nothing we’ve ever seen before,” he said. “It’s very high in sulphur, it’s very high in magnesium, it’s got twice as much manganese as we’ve ever seen in anything on Mars.

    “I don’t know what any of this means. We’re completely confused, and everyone in the team is arguing and fighting (over what it means).

    “That’s the beauty of this mission… what I’ve realised is that we will never be finished. There will always be something tantalising, something wonderful just beyond our reach that we didn’t quite get to – and that’s the nature of exploration.”

    Squyres was speaking at an event marking the 10th anniversary of the arrival of Opportunity and Spirit on the surface of Mars.

    While Spirit lost contact with Earth and was later declared “dead” in 2010, Opportunity has now roamed the planet far in excess of what was originally planned as a three-month mission. Nasa said that with its maximum speed of just 0.05mph, as of “Sol 3547” (15 January 2014) Opportunity had covered just over 24 miles (38km).

    source independent
     
    Top