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    VIRGOCosmos In Brief - Aktualní novinky vesmírného výzkumu v kostce
    VIRGO
    VIRGO --- ---
    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
    VIRGO
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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. 



    VIRGO
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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
    VIRGO --- ---
    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.
    VIRGO
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    Four Earth-sized planets detected orbiting the nearest sun-like star
    https://news.ucsc.edu/2017/08/tau-ceti-planets.html

    A new study by an international team of astronomers reveals that four Earth-sized planets orbit the nearest sun-like star, tau Ceti,
    which is about 12 light years away and visible to the naked eye. These planets have masses as low as 1.7 Earth mass, making them among
    the smallest planets ever detected around nearby sun-like stars. Two of them are super-Earths located in the habitable zone of the star,
    meaning they could support liquid surface water.

    The planets were detected by observing the wobbles in the movement of tau Ceti. This required techniques sensitive enough to detect
    variations in the movement of the star as small as 30 centimeters per second.

    "We are now finally crossing a threshold where, through very sophisticated modeling of large combined data sets from multiple independent
    observers, we can disentangle the noise due to stellar surface activity from the very tiny signals generated by the gravitational tugs from
    Earth-sized orbiting planets," said coauthor Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz.

    VIRGO
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    The Fate of Merging Neutron Stars
    http://aasnova.org/2017/08/09/the-fate-of-merging-neutron-stars/

    When two neutron stars collide, the new object that they make can reveal information about the interior
    physics of neutron stars. New theoretical work explores what we should be seeing, and what it can teach us.

    So far, the only systems from which we’ve detected gravitational waves are merging black holes. But other
    compact-object binaries exist and are expected to merge on observable timescales — in particular, binary
    neutron stars. When two neutron stars merge, the resulting object falls into one of three categories:

    - a stable neutron star,
    - a black hole, or
    - a supramassive neutron star, a large neutron star that’s supported by its rotation
    but will eventually collapse to a black hole after it loses angular momentum.

    VIRGO
    VIRGO --- ---
    Lunar dynamo’s lifetime extended by at least 1 billion years | MIT News
    http://news.mit.edu/2017/lunar-dynamo-lifetime-extended-least-1-billion-years-0809

    Findings suggest two mechanisms may have powered the moon’s ancient churning, molten core.

    New evidence from ancient lunar rocks suggests that an active dynamo once churned within the molten metallic core of the moon,
    generating a magnetic field that lasted at least 1 billion years longer than previously thought. Dynamos are natural generators
    of magnetic fields around terrestrial bodies, and are powered by the churning of conducting fluids within many stars and planets.

    In a paper published today in Science Advances, researchers from MIT and Rutgers University report that a lunar rock collected by
    NASA’s Apollo 15 mission exhibits signs that it formed 1 to 2.5 billion years ago in the presence of a relatively weak magnetic
    field of about 5 microtesla. That’s around 10 times weaker than Earth’s current magnetic field but still 1,000 times larger than
    fields in interplanetary space today.

    VINCENT_BU
    VINCENT_BU --- ---
    VIRGO: tady se to nepíše tak kategoricky, příští měsíc má padnout oficiální rozhodnutí, byť zástupci NASA připouštějí, že několikaměsíční odklad JWST neublíží :)
    http://www.americaspace.com/2017/08/06/schedule-conflict-may-delay-launch-of-james-webb-space-telescope-to-2019/
    VINCENT_BU
    VINCENT_BU --- ---
    VIRGO: tenhle chlapík se obvykle drží při zemi, ale tentokrát přidal pár úvah k možnosti Dyson sphere:
    KIC 8462852 Update for 07/15/2017
    https://www.youtube.com/watch?v=OabY1bKB974
    VIRGO
    VIRGO --- ---
    VIRGO:

    In this animation, we are at the centre looking out. Each dot is a galaxy that has been mapped by various surveys.
    The orange region contains the galaxies the Dark Energy Survey team observed. The sparkling in the long gold regions
    are supernova explosions. The empty spaces aren’t truly empty, they are just places we haven’t looked yet. Credit:
    Samuel Hinton, University of Queensland.

    DES+OzDES, WiggleZ, GAMA, 2dF, 6dF, & SDSS - 3D Galaxy Visualization
    https://www.youtube.com/watch?v=J_ZQfMWQtsA


    What a new map of the universe tells us about dark matter
    https://theconversation.com/what-a-new-map-of-the-universe-tells-us-about-dark-matter-82074
    VIRGO
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    Bennu alert! OSIRIS-REx's target asteroid was recently spotted for the first time
    since 2013 by the Pan-STARRS 1 telescope on Maui. The Minor Planet Center keeps records
    of all published observations of Bennu.

    IAU Minor Planet Center
    http://www.minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=101955

    Shape model from radar observations at The Arecibo Observatory, work led by Mike Nolan.

    VIRGO
    VIRGO --- ---
    2014 MU69 shadow traces its most likely binary shape, as seen in the stellar occultation that occurred over
    Argentina on July 17, 2017. The best-fit red circles reveal MU69's possible doubled-lobed – or binary – nature.

    Credit: NASA/JHUAPL/SwRI/Alex Parker

    VIRGO
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    The light from KIC 8462852 faded again, and scientists have some new
    theories about what's behind astronomy's most mysterious star.

    We’re STILL Not Saying It’s Aliens, But Tabby’s Star Is Getting Weirder
    https://www.youtube.com/watch?v=8XDS_aTVBrE


    The new dip is significant enough to be given a name.
    Tabby and team have dubbed the current dip "Skara Brae", and this thread
    is for discussion of the data, observations and closely related matters.

    https://www.reddit.com/r/KIC8462852/comments/6sefv0/the_skara_brae_dip_of_august_2017/
    Kliknutím sem můžete změnit nastavení reklam