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    VIRGOCosmos In Brief - Aktualní novinky vesmírného výzkumu v kostce
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    The Air out There: Astronomers Aim to Find Atmospheres of Alien Earths - Scientific American
    https://www.scientificamerican.com/...out-there-astronomers-aim-to-find-atmospheres-of-alien-earths/

    Is our nearest neighboring exoplanet, Proxima b, an "Earth next door," or is it a lifeless rock?

    Remotely sniffing the air of these tantalizing worlds is no easy task, and is unlikely to occur sooner than the end of this decade, if not well into the next.
    The first observations could be made by NASA’s infrared James Webb Space Telescope, launching in 2018, followed in the mid-2020s by a new generation of ground-
    based “Extremely Large Telescopes” with 30-meter mirrors. However, the payoff could be immense: In a forthcoming paper submitted to The Astrophysical Journal,
    the Harvard-Smithsonian Center for Astrophysics astronomer Caroline Morley and colleagues conclude that with a total investment of as little as a week of
    observing time Webb could conceivably deliver statistically significant detections of Earth-like atmospheric conditions upon a handful of small planets transiting
    nearby red dwarf stars. Or, of course, Webb could find instead that those worlds are airless rocks. Whether such investments will happen at all is far from certain:
    With a nominal lifetime of only five years and astronomers worldwide clamoring to use it, the telescope is destined to become the most oversubscribed and in-demand
    scientific instrument humans have ever built.

    In the meantime some researchers are focusing on ways to use Webb to simply detect an atmosphere—or rule one out—upon the closest potentially life-friendly red-dwarf
    world. Find that Proxima b has managed to keep an appreciable atmosphere in spite of the barrage of physical insults from its stellar host, and you have taken a big
    step toward showing the universe is filled with biologically promising red-dwarf worlds. Finding it has no atmosphere could, by contrast, bolster the case that red
    dwarfs are by and large dead-ends in the search for alien life.

    “It may sound arrogant, but using Webb to prove that Proxima b has an atmosphere would be one of the biggest scientific achievements it could make,” says Ignas
    Snellen, an astronomer at the University of Leiden. “If Webb does that, I think the project would have to be considered a success, no matter what else it does.”

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    Cosmology Results from The Dark Energy Survey! | astrobites
    https://astrobites.org/2017/08/14/cosmology-results-from-the-dark-energy-survey/

    The Dark Energy Survey (DES) is a 5-year long endeavor meant to map astrophysical objects over 1/8th of the total night sky visible from Earth (5000 square degrees!),
    making it one of the largest all-sky surveys ever undertaken from the Earth. DES, which has been in operation since 2013 and is being considered the natural successor
    to the Sloan Digital Sky Survey (SDSS), uses the 4m Blanco Telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile for its observations.

    VIRGO
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    The Cosmic Velocity Web
    http://www.ifa.hawaii.edu/info/press-releases/velocity_web/

    The cosmic web - the distribution of matter on the largest scales in the universe - has usually been defined through the distribution of galaxies.
    Now, a new study by a team of astronomers from France, Israel, and Hawaii demonstrates a novel approach. Instead of using galaxy positions, they
    mapped the motions of thousands of galaxies. Because galaxies are pulled toward gravitational attractors and move away from empty regions, these
    motions allowed the team to locate the denser matter in clusters and filaments and the absence of matter in regions called voids.

    Matter was distributed almost homogeneously in the very early universe, with only miniscule variations in density. Over the 14 billion year history
    of the universe, gravity has been acting to pull matter together in some places and leave other places more and more empty. Today, the matter forms
    a network of knots and connecting filaments referred to as the cosmic web. Most of this matter is in a mysterious form, the so-called "dark matter".
    Galaxies have formed at the highest concentrations of matter and act as lighthouses illuminating the underlying cosmic structure.

    The newly defined cosmic velocity web defines the structure of the universe from velocity information alone. In those regions with abundant observations,
    the structure of the velocity web and the web inferred from the locations of the galaxy lighthouses are similar. This agreement provides strong confirmation
    of the fundamental idea that structure developed from the growth of initially tiny fluctuations through gravitational attraction.

    The cosmic velocity web analysis was led by Daniel Pomarede, Atomic Energy Center, France, with the collaboration of Helene Courtois at the University
    of Lyon, France; Yehuda Hoffman at the Hebrew University, Israel; and Brent Tully at the University of Hawai'i Institute for Astronomy.

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    http://minorplanetcenter.net/db_search/show_object?object_id=3122

    https://cneos.jpl.nasa.gov/about/neo_groups.html

    Potentially hazardous asteroid 3122 (1981 ET 3) Florence (named after Florence Nightingale) was discovered back in March 1981 by American
    astronomer Schelte Bus at the Siding Spring Observatory, New South Wales. It orbits the Sun once every 2 years and 4 months. On September 01,
    2017, the 4.35 kilometer space rock will fly by the Earth at a distance of just under 4.4 million miles. It sounds far but this is close enough
    for an object of this size to be observed in a small telescope if you know where to look. This is the closest this asteroid has has passed
    the Earth since 1890.

    Thought to be the parent body of the Geminid meteor shower, this is one of the largest asteroids on the Potentially Harzardous Asteroid list.

    Current estimates expect the asteroid to reach around visual magnitude 9 making it a relatively easy target for backyard astronomers at a dark
    site. It will be travelling at over 30,000 miles per hour however because of its distance, the small speck of light will appear to move quite
    slowly in the sky against the background stars.

    http://www.cometwatch.co.uk/asteroid-3122-florence-earth-flyby/

    https://watchers.news/2017/08/14/3122-florence-asteroid-flyby-september-1-2017/
    VIRGO
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    Voyager 2's 11 billion mile journey at a human scale
    https://www.youtube.com/watch?v=wgDr26MvWKQ
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    Cosmic Magnifying Lens Reveals Inner Jets of Black Holes | Caltech
    http://www.caltech.edu/news/cosmic-magnifying-lens-reveals-inner-jets-black-holes-79330

    Astronomers using Caltech's Owens Valley Radio Observatory (OVRO) have found evidence for a bizarre lensing system in space,
    in which a large assemblage of stars is magnifying a much more distant galaxy containing a jet-spewing supermassive black hole.
    The discovery provides the best view yet of blobs of hot gas that shoot out from supermassive black holes.

    VIRGO
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    VIRGO:

    NASA and ESA Spacecraft Track a Solar Storm Through Space
    https://www.youtube.com/watch?v=6N8WZvZCQ7E


    https://www.nasa.gov/feature/goddard/2017/nasa-esa-spacecraft-track-solar-storm-through-space
    VIRGO
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    https://www.nasa.gov/image-feature/jpl/pia21341/cloudy-waves-false-color

    This false color view is centered on 46 degrees north latitude on Saturn. The images were taken with the Cassini spacecraft narrow-angle camera on May 18,
    2017 using a combination of spectral filters which preferentially admit wavelengths of near-infrared light. The image filter centered at 727 nanometers was used
    for red in this image; the filter centered at 750 nanometers was used for blue. (The green color channel was simulated using an average of the two filters.)

    VIRGO
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    https://www.nasa.gov/feature/goddard/2017/nasa-studies-cubesat-mission-to-solve-venusian-mystery

    Venus looks bland and featureless in visible light, but change the filter to ultraviolet, and Earth’s twin suddenly looks like a different
    planet. Dark and light areas stripe the sphere, indicating that something is absorbing ultraviolet wavelengths in the planet’s cloud tops.

    A team of scientists and engineers working at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has received funding from the agency’s
    Planetary Science Deep Space SmallSat Studies, or PSDS3, program to advance a CubeSat mission concept revealing the nature of this mysterious
    absorber situated within the planet’s uppermost cloud layer.

    Called the CubeSat UV Experiment, or CUVE, the mission would investigate Venus’ atmosphere using ultraviolet-sensitive instruments and a novel,
    carbon-nanotube light-gathering mirror.

    VIRGO
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    +6
    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
    VIRGO
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    1 odpověď
    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.

    VIRGO
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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.

    VIRGO
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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.

    VIRGO
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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
    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
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