Explanation: The constellation of Orion is much more than three stars in a row. It is a direction in space that is rich with impressive nebulas. To better appreciate this well-known swath of sky, a new long exposure image was taken over several clear nights in January, February and March. After 23 hours of camera time and untold hours of image processing, the featured collage in the light of hydrogen, oxygen, and sulfur was produced spanning over 40 times theangular diameter of the Moon. Of the many interesting details that have become visible, one that particularly draws the eye is Barnard's Loop, the bright red orange arc just to the right of the image center. The Rosette Nebula is not the giant orange nebula just to the left of the image center -- that is larger but lesser known nebula known as the Meissa Ring. The Rosette Nebula is visible, though: it is the bright orange, blue and white nebula near the image bottom. The bright orange star just left of the frame center is Betelgeuse, while the bright blue star on the upper right is Rigel. About those famous three stars that cross the belt of Orion the Hunter -- in this busy frame they can be hard to locate, but a discerning eye will find them just to the right of the image center.
Nombre total de pages vues
05/06/2019
Science & Technology - Astronomy picture of the day : The Interstellar Clouds of Orion
04/06/2019
Science & Technology - Astronomy picture of the day : SEIS: Listening for Marsquakes
Image Credit: NASA, JPL-Caltech, Mars Insight
Explanation: If you put your ear to Mars, what would you hear? To find out, and to explore the unknown interior of Mars, NASA's Insight Lander deployed SEIS late last year, a sensitive seismometer that can detect marsquakes. In early April, after hearing the wind and motions initiated by the lander itself, SEIS recorded an unprecedented event that matches what was expected for a marsquake. This event can be heard on this YouTube video. Although Mars is not thought to have tectonic plates like the Earth, numerous faults are visible on the Martian surface which likely occurred as the hot interior of Mars cooled -- and continues to cool. Were strong enough marsquakes to occur, SEIScould hear their rumbles reflected from large structures internal to Mars, like a liquid core, if one exists. Pictured last week, SEIS sits quietly on the Martian surface, taking in some Sun while light clouds are visible over the horizon.
03/06/2019
Science & Technology - Astronomy picture of the day : Stephan's Quintet from Hubble
Image Credit: NASA, ESA, Hubble; Processing: Daniel Nobre
Explanation: When did these big galaxies first begin to dance? Really only four of the five of Stephan's Quintet are locked in a cosmic tango of repeated close encounters taking place some 300 million light-years away. The odd galaxy out is easy to spot in this recently reprocessed image by the Hubble Space Telescope -- the interacting galaxies, NGC 7319, 7318B, 7318A, and 7317 (left to right), have a more dominant yellowish cast. They also tend to have distorted loops and tails, grown under the influence of disruptive gravitational tides. The mostly bluish galaxy, large NGC 7320 on the lower left, is in the foreground at about 40 million light-years distant, and so is not part of theinteracting group. Data and modeling indicate that NGC 7318B is a relatively new intruder. A recently-discovered halo of old red stars surrounding Stephan's Quintet indicate that at least some of these galaxies started tangling over a billion years. Stephan's Quintet is visible with a moderate sized-telescope toward the constellation of Winged Horse (Pegasus).
02/06/2019
Science & Technology - Astronomy picture of the day - A Live View from the International Space Station
Image Credit: NASA, UStream, HDEV Project
Explanation: If you were floating above the Earth right now, this is what you might see. In 2014, a robotic SpaceX Dragon capsule that delivered supplies to the Earth-orbiting International Space Station (ISS) also delivered High Definition Earth Viewing (HDEV) cameras that take and transmit live views of Earth. Pictured here, when working, is the live video feed that switches between four cameras, each pointed differently. Watch white clouds, tan land, andblue oceans drift by. The featured live view will appear black when it is nighttime on the Earth below, but the space station's rapid 90-minute orbit compresses this dark time into only 45 minutes. The present location of the ISS above the Earth can be found on the web. If the video appears gray, this indicates that the view is either being switched between cameras, or communications with the ISS is temporarily unavailable. As the HDEV project continues, video quality will be monitored to assess the effects of high energy radiation, which types of cameras work best, and which Earth views are the most popular.
Science & Technologie - Aeronautique : "Voltige en hélicoptère au-dessus de New York
"Voltige en hélicoptère au-dessus de New York"
Du grand spectacle dans les airs. Un hélicoptère a enchainé les figures acrobatiques au-dessus de New York ce samedi 18 mai. Avec la statut de la Liberté et les gratte-ciels pour terrain de jeu, c’est un ancien pilote chevronné de l’armée américaine Aaron Fitzgerald qui était aux commandes. Il compte plus de 8 500 heures de vol. Ses tonneaux, boucles et autres piqués sont impressionnants à voir, notamment depuis le cockpit (vidéo). Il s’agissait là d’une répétition pour un meeting aérien (Bethpage Air Show) qui se tenait le week-end dernier au-dessus d’une plage de Long Island et auquel a participé la patrouille acrobatique de l’US Air Force, les Thunderbirds.
La machine utilisée pour les figures est un BO105, un hélicoptère bimoteur développé par le constructeur allemand MBB (Messerschmitt-Bölkow-Blohm, aujourd’hui Airbus Helicopters). Grâce à sa tête de rotor rigide en titane et ses quatre pales en fibre de verre, le BO105 est capable d’exécuter les figures de voltige les plus folles. Vous l’avez d’ailleurs sans doute déjà vu au cinéma dans le dernier James Bond (Spectre) notamment pour effectuer des acrobaties au-dessus de Mexico.
Aeronewstv
01/06/2019
Science & Technology - Astronomy picture of the day - Lynds Dark Nebula 1251
Image Credit & Copyright: Francesco Sferlazza, Franco Sgueglia, Astro Brallo
Explanation: Stars are forming in Lynds Dark Nebula (LDN) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, the dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare region. Across the spectrum, astronomical explorations of the obscuring interstellar clouds reveal energetic shocks and outflows associated with newborn stars, including the telltale reddish glow from scattered Herbig-Haro objects seen in this sharp image. Distant background galaxies also lurk on the scene, visually buried behind the dusty expanse. The deep telescopic field of view imaged with broadband filters spans about two full moons on the sky, or 17 light-years at the estimated distance of LDN 1251.
31/05/2019
Science & Technologie - Video - Aeronautique : Les 50 ans d'Airbus
L'A220, l'A320, l'A350, l'A380 et le BelugaXL réunis pour un vol en formation : voilà comment Airbus a lancé les festivités de son cinquantième anniversaire, le mercredi 29 mai. Cinquante jours de célébrations sont prévues jusqu'au 17 juillet. L'anniversaire sera bien entendu célébré lors du Salon du Bourget, du 17 au 23 juin.
Le 29 mai, les avions stars de l'avionneur ont donc volé de façon synchronisée au dessus de Toulouse.
Usine Nouvelle
30/05/2019
Science & Technology - Astronomy picture of the day : Sunrise at Copernicus Crater
Image Credit & Copyright: Sage Gray
Explanation: A prominent impact site anchored in the lunar Oceanus Procellarum, Copernicus crater is at the center of this telescopic portrait in light and shadow. Caught in stacked and sharpened video frames recorded on April 14 at 3:30am UTC, the lunar terminator, or boundary between night and day, cuts across the middle of the 93 kilometer diameter crater. Sunlight is just beginning to strike its tall western walls but doesn't yet shine on lower terrain nearby, briefly extending the crater's outline into the lunar nightside. At that moment standing at Copernicus crater you could watch the sunrise, an event that happens at Copernicus every 29.5 days. Of course that corresponds to a lunar month or a lunation, the time between consecutive Full Moons, as seen from planet Earth.
29/05/2019
Science & Technology - Astronomy picture of the day : A Solar Prominence Eruption from SDO
Image Credit & Copyright: NASA/Goddard/SDO AIA Team
Explanation: One of the most spectacular solar sights is an erupting prominence. In 2011, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressively large prominence erupting from the surface. The dramatic explosion was captured in ultraviolet light in the featured time lapse video covering 90 minutes, where a new frame was taken every 24 seconds. The scale of the prominence is huge -- the entire Earth would easily fit under the flowingcurtain of hot gas. A solar prominence is channeled and sometimes held above the Sun's surface by the Sun's magnetic field. A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME)expelling hot gas into the Solar System. The energy mechanism that creates a solar prominence is still a topic of research. After our Sun passes the current Solar Minimum, solar activity like eruptive prominences are expected to become more common over the next few years.
28/05/2019
Science & Technologie - Avions du futur : L'aile rhomboédrique
Une idée explorée pour réduire les traînées aérodynamiques aux extrémités des ailes : les supprimer ! C'est possible avec une forme rhomboédrique, qui se referme sur l'empennage. Aérodynamiquement, cette forme a un allongement infini (l'allongement étant le rapport entre la longueur de l'aile et sa surface). L'idée n'est pas nouvelle et a déjà été testée. Elle pose des problèmes de résistance de matériaux et de trop grande rigidité. Des nouveaux matériaux pourraient la rendre possible...
© Bauhaus Luftfahrt
Inscription à :
Articles (Atom)
ASTRONOMIE - Galaxies - NGC 4414
Une galaxie spirale . (photo HST, APOD 09/09/1999)
-
2021 May 11 Lightning and Orion Beyond Uluru Image Credit & Copyright: Park Liu Explanation: What's happening behind Uluru? A Un...
-
2021 January 3 A Phoenix Aurora over Iceland Image Credit & Copyright: Hallgrimur P. Helgason ; Rollover Annotation: Judy Schmidt Ex...