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    VIRGOCosmos In Brief - Aktualní novinky vesmírného výzkumu v kostce
    VIRGO
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    Přesně za měsíc Cassini zanikne...



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    In Hunting Supernovae, 'Get Them While They're Young' | UANews
    https://uanews.arizona.edu/story/hunting-supernovae-get-them-while-theyre-young

    Thanks to a global network of telescopes, astronomers have caught the fleeting explosion of a Type Ia supernova
    in unprecedented detail. Because this type of supernova is commonly used as a cosmic yardstick, a better understanding
    of how they form could have implications for future dark energy measurements.

    VIRGO
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    Tidally locked exoplanets may be more common than previously thought | UW News
    http://www.washington.edu/...4/tidally-locked-exoplanets-may-be-more-common-than-previously-thought/

    Many exoplanets to be found by coming high-powered telescopes will probably be tidally locked — with one side permanently
    facing their host star — according to new research by astronomer Rory Barnes of the University of Washington.

    Barnes, a UW assistant professor of astronomy and astrobiology, arrived at the finding by questioning the long-held assumption that only those stars
    that are much smaller and dimmer than the sun could host orbiting planets that were in synchronous orbit, or tidally locked, as the moon is with the
    Earth. His paper, “Tidal Locking of Habitable Exoplanets,” has been accepted for publication by the journal Celestial Mechanics and Dynamical Astronomy.

    Tidal locking results when there is no side-to-side momentum between a body in space and its gravitational partner and they become fixed in their embrace.
    Tidally locked bodies such as the Earth and moon are in synchronous rotation, meaning that each takes exactly as long to rotate around its own axis as it
    does to revolve around its host star or gravitational partner. The moon takes 27 days to rotate once on its axis, and 27 days to orbit the Earth once.
    VIRGO
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    ISS Crew Readies for Unique View of the Solar Eclipse
    https://www.youtube.com/watch?v=_0WJFIVQOv4
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    Tracking a solar eruption through the Solar System / Space Science / Our Activities / ESA
    http://www.esa.int/Our_Activities/Space_Science/Tracking_a_solar_eruption_through_the_Solar_System

    Ten spacecraft, from ESA’s Venus Express to NASA’s Voyager-2, felt the effect of a solar eruption as it washed through
    the Solar System while three other satellites watched, providing a unique perspective on this space weather event.

    Scientists working on ESA’s Mars Express were looking forward to investigating the effects of the close encounter of Comet
    Siding Spring on the Red Planet’s atmosphere on 19 October 2014, but instead they found what turned out to be the imprint
    of a solar event.

    While this made the analysis of any comet-related effects far more complex than anticipated, it triggered one of the largest
    collaborative efforts to trace the journey of an interplanetary ‘coronal mass ejection’ – a CME – from the Sun to the far
    reaches of the outer Solar System.

    Although Earth itself was not in the firing line, a number of Sun-watching satellites near Earth – ESA’s Proba-2, the ESA/NASA
    SOHO and NASA’s Solar Dynamics Observatory – had witnessed a powerful solar eruption a few days earlier, on 14 October.

    NASA’s Stereo-A not only captured images of the other side of the Sun with respect to Earth, but also collected in situ
    information as the CME rushed passed.

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    http://greenbankobservatory.org/lunar_radar/

    Researchers from the Smithsonian’s National Air and Space Museum are using radio telescopes at the Arecibo Observatory and Green Bank Observatory to map the Moon
    with radar. The radar signals, transmitted from the Arecibo telescope and received at the Robert C. Byrd Green Bank Telescope, can probe many meters below the surface
    of the Moon, just like ground-piercing radar on Earth. They reveal Lunar structures that can’t be seen in optical images because they’re hidden from view under the layer
    of dust and rubble that covers the Moon’s surface. The scientists are searching for unseen structures of Lunar geology such as lava flow complexes and buried craters.

    This is a radar view of the Moon’s southeastern highlands, showing the densely cratered surface formed as the result of more than 4 billion years of meteorite impacts.
    The radar can distinguish the age of some craters. Younger impact craters have enhanced radar return showing bright floors and surrounding areas due to rocky material
    that has not yet been worn away by very small meteorites.

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    https://www.nasa.gov/feature/jpl/trappist-1-is-older-than-our-solar-system

    At the time of its discovery, scientists believed the TRAPPIST-1 system had to be at least 500 million years old, since it takes stars of TRAPPIST-1’s low mass
    (roughly 8 percent that of the Sun) roughly that long to contract to its minimum size, just a bit larger than the planet Jupiter. However, even this lower age
    limit was uncertain; in theory, the star could be almost as old as the universe itself. Are the orbits of this compact system of planets stable? Might life have
    enough time to evolve on any of these worlds?

    VIRGO
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    https://www.nasa.gov/feature/goddard/2017/nasa-watches-the-sun-put-a-stop-to-its-own-eruption

    On Sept. 30, 2014, multiple NASA observatories watched what appeared to be the beginnings of a solar eruption. A filament —
    a serpentine structure consisting of dense solar material and often associated with solar eruptions — rose from the surface,
    gaining energy and speed as it soared. But instead of erupting from the Sun, the filament collapsed, shredded to pieces by
    invisible magnetic forces.

    Sun Shreds Its Own Eruption
    https://www.youtube.com/watch?v=W23QnzEc-bc
    VIRGO
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    Have Two Lonely Trans-Neptunian Objects Found Each Other?
    http://aasnova.org/2017/08/11/have-two-lonely-trans-neptunian-objects-found-each-other/

    A new study has identified 2004 TT357 as a body that may be made up of two separate objects in contact with each other.

    Though Hubble can’t recognize distant contact binaries because the components are too close together, we can potentially
    identify them from their characteristic light curves. But this is a challenging process, and so far we’ve only found one
    confirmed trans-Neptunian-object (TNO) contact binary and one candidate — despite predictions that 10–30% of TNOs could
    be contact binaries.

    Now, new observations from the 4.3-m Lowell Observatory Discovery Channel Telescope, presented in a study led by Audrey
    Thirouin (Lowell Observatory), have resulted in the identification of a potential new TNO contact binary.

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    https://www.olcf.ornl.gov/...lactic-winds-push-researchers-to-probe-galaxies-at-unprecedented-scale/

    When astronomers peer into the universe, what they see often exceeds the limits of human understanding.
    Such is the case with low-mass galaxies—galaxies a fraction of the size of our own Milky Way.

    These small, faint systems made up of millions or billions of stars, dust, and gas constitute the most common type
    of galaxy observed in the universe. But according to astrophysicists’ most advanced models, low-mass galaxies should
    contain many more stars than they appear to contain.

    Cool Cloud
    https://vimeo.com/228856875
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    The Implications of Cosmic Silence | University of Arkansas
    http://news.uark.edu/articles/39255/the-implications-of-cosmic-silence

    The universe is incomprehensibly vast, with billions of other planets circling billions of other stars.
    The potential for intelligent life to exist somewhere out there should be enormous.

    So, where is everybody?

    That’s the Fermi paradox in a nutshell. Daniel Whitmire, a retired astrophysicist who teaches mathematics
    at the University of Arkansas, once thought the cosmic silence indicated we as a species lagged far behind.

    “I taught astronomy for 37 years,” said Whitmire. “I used to tell my students that by statistics, we have
    to be the dumbest guys in the galaxy. After all we have only been technological for about 100 years while
    other civilizations could be more technologically advanced than us by millions or billions of years.”

    Recently, however, he’s changed his mind. By applying a statistical concept called the principle of mediocrity –
    the idea that in the absence of any evidence to the contrary we should consider ourselves typical, rather than
    atypical – Whitmire has concluded that instead of lagging behind, our species may be average. That’s not good news.

    In a paper published Aug. 3 in the International Journal of Astrobiology, Whitmire argues that if we are typical,
    it follows that species such as ours go extinct soon after attaining technological knowledge.

    The argument is based on two observations: We are the first technological species to evolve on Earth, and we are
    early in our technological development. (He defines “technological” as a biological species that has developed
    electronic devices and can significantly alter the planet.)

    The first observation seems obvious, but as Whitmire notes in his paper, researchers believe the Earth should be
    habitable for animal life at least a billion years into the future. Based on how long it took proto-primates to
    evolve into a technological species, that leaves enough time for it to happen again up to 23 times. On that time
    scale, there could have been others before us, but there’s nothing in the geologic record to indicate we weren’t
    the first. “We’d leave a heck of a fingerprint if we disappeared overnight,” Whitmire noted.

    http://realdanielwhitmire.wixsite.com/home/copy-of-astrobiology-1
    VIRGO
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    A Starburst with the Prospect of Gravitational Waves | NASA
    https://www.nasa.gov/...ges/chandra/images/a-starburst-with-the-prospect-of-gravitational-waves.html

    In 1887, American astronomer Lewis Swift discovered a glowing cloud, or nebula, that turned out to be a small galaxy about 2.2 billion
    light years from Earth. Today, it is known as the “starburst” galaxy IC 10, referring to the intense star formation activity occurring there. 



    More than a hundred years after Swift’s discovery, astronomers are studying IC 10 with the most powerful telescopes of the 21st century.
    New observations with NASA’s Chandra X-ray Observatory reveal many pairs of stars that may one day become sources of perhaps the most exciting
    cosmic phenomenon observed in recent years: gravitational waves.



    By analyzing Chandra observations of IC 10 spanning a decade, astronomers found over a dozen black holes and neutron stars feeding off gas from
    young, massive stellar companions. Such double star systems are known as “X-ray binaries” because they emit large amounts of X-ray light. As
    a massive star orbits around its compact companion, either a black hole or neutron star, material can be pulled away from the giant star to form
    a disk of material around the compact object. Frictional forces heat the infalling material to millions of degrees, producing a bright X-ray source. 



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    https://www.nasa.gov/...ay-to-night-and-back-again-earth-s-ionosphere-during-the-total-solar-eclipse

    On Aug. 21, 2017, the Moon will slide in front of the Sun and for a brief moment, day will melt into a dusky night. Moving across the country,
    the Moon’s shadow will block the Sun’s light, and weather permitting, those within the path of totality will be treated to a view of the Sun’s
    outer atmosphere, called the corona.

    But the total solar eclipse will also have imperceptible effects, such as the sudden loss of extreme ultraviolet radiation from the Sun, which
    generates the ionized layer of Earth’s atmosphere, called the ionosphere. This ever-changing region grows and shrinks based on solar conditions,
    and is the focus of several NASA-funded science teams that will use the eclipse as a ready-made experiment, courtesy of nature.

    VIRGO
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    About your cat, Mr. Schrödinger - I have good news and bad news...

    VIRGO
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    Here's what we know about the 12 proposals for NASA's next New Frontiers mission | The Planetary Society
    http://www.planetary.org/blogs/guest-blogs/van-kane/20170810-new-frontiers-missions.html

    NASA’s managers are in the process of selecting the agency’s next planetary mission from a field of twelve competitors.
    This fourth mission in the New Frontiers program will follow in the footsteps of the three missions in this program that
    have already launched: The New Horizons Pluto spacecraft, the Juno Jupiter orbiter, and the OSIRIS-REx asteroid sample
    return mission.

    VIRGO
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    Preserving the stress of volcanic uprise on Mars / Mars Express / Space Science / Our Activities / ESA
    http://www.esa.int/...es/Space_Science/Mars_Express/Preserving_the_stress_of_volcanic_uprise_on_Mars

    An ancient mountain range on Mars preserves a complex volcanic and tectonic past imprinted with signs of water and ice interactions.

    The images, taken on 9 April by the high-resolution stereo camera on ESA’s Mars Express, show the Thaumasia mountains and Coracis Fossae,
    which fringe the huge Solis Planum volcanic plateau from the south.

    The region lies to the south of the vast Valles Marineris canyon system and towering Tharsis volcanoes, and is strongly linked
    to the tectonic stresses that played out during their formation over 3.5 billion years ago.

    VIRGO
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    Watch Martian Clouds Scoot, Thanks to NASA's Curiosity | Mars News
    https://mars.nasa.gov/news/2017/watch-martian-clouds-scoot-thanks-to-nasas-curiosity

    Wispy, early-season clouds resembling Earth's ice-crystal cirrus clouds move across
    the Martian sky in some new image sequences from NASA's Curiosity Mars rover.

    VIRGO
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    New observations reveal Crab Nebula's polarised emissions for first time | KTH
    https://www.kth.se/...-observations-reveal-crab-nebula-s-polarised-emissions-for-first-time-1.746056

    The researchers' observations of polarised X-rays from the Crab Nebula and Pulsar, published today in Scientific Reports, may help
    explain sudden flares in the Crab’s X-ray intensity, as well as provide new data for modeling – and understanding – the nebula.

    The polarisation of Crab X-rays reveals how and where they are produced in the extreme environment of the nebula, says Mark Pearce,
    Professor of Physics at KTH Royal Institute of Technology and lead author of the study.

    “Our measurements indicate that the X-rays come from an organized region in the vicinity of the pulsar at the centre of the nebula,"
    Pearce says. "Electrons gyrating around magnetic field lines in this region produce the X-rays. The measurements are made in an unexplored
    energy range, so they provide new information which will help to solve the puzzle of how high energy radiation is generated.”

    VIRGO
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    Space in Images - 2017 - 08 - Asteroid 2012 TC4 will fly past Earth in October 2017
    http://www.esa.int/...einimages/Images/2017/08/Asteroid_2012_TC4_will_fly_past_Earth_in_October_2017

    A small asteroid flying past Earth on 12 October will provide scientists with a valuable opportunity to learn more about its orbit and
    composition. The campaign will exercise the international network of observatories and research organisations working on planetary defence.

    Astronomers recently spotted asteroid 2012 TC4 under a collaboration between ESA and the European Southern Observatory (ESO) to locate faint
    objects that might strike Earth. This is the first observation since 2012, when the asteroid was discovered by the Pan-STARRS observatory in
    Hawaii. It was found this time by ESO’s Very Large Telescope in Chile.

    The original observations revealed the asteroid’s next approach to our vicinity would be in October 2017 but its orbit meant that it could
    not be tracked during the last five years, leaving astronomers unsure on how close it would come.

    The new observations reveal it will miss Earth by 44 000 km. While it remains visible, astronomers will study the 15–30 m object in as much
    detail as possible, such as obtaining information on its composition.

    VIRGO
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    NASA Selects Proposals to Study Galaxies, Stars, Planets
    https://www.nasa.gov/press-release/nasa-selects-proposals-to-study-galaxies-stars-planets

    NASA has selected six astrophysics Explorers Program proposals for concept studies. The proposed missions would study gamma-ray and X-ray emissions
    from clusters of galaxies and neutron star systems, as well as infrared emissions from galaxies in the early universe and atmospheres of exoplanets,
    which are planets outside of our solar system.

    The selected proposals, three Medium-Class Explorers missions and three Explorers Missions of Opportunity, call for focused scientific investigations
    and developments of instruments that fill the scientific gaps between the agency’s larger missions.

    “The Explorers Program brings out some of the most creative ideas for missions to help unravel the mysteries of the universe,” said Thomas Zurbuchen,
    associate administrator of the agency’s Science Mission Directorate in Washington. “The program has resulted in great missions that have returned
    transformational science, and these selections promise to continue that tradition.”

    The proposals were selected based on potential science value and feasibility of development plans. After concept studies and detailed evaluations,
    one of each mission type will be selected by 2019 to proceed with construction and launch. The earliest launch date would be in 2022. Medium-Class
    Explorer mission costs are capped at $250 million each, excluding the launch vehicle, and Mission of Opportunity costs are capped at $70 million each.
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