Science & Technology - Astronomy picture of the day : Stephan's Quintet from Hubble

2019 June 3
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).

Science & Technology - Astronomy picture of the day - A Live View from the International Space Station

2019 June 2
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

Science & Technology - Astronomy picture of the day - Lynds Dark Nebula 1251

2019 May 31
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.

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

Science & Technology - Astronomy picture of the day : Sunrise at Copernicus Crater

2019 May 30
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.

Science & Technology - Astronomy picture of the day : A Solar Prominence Eruption from SDO

2019 May 26
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.

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

Science & Technologie - Aeronautique : Ces ailes révolutionnaires d’Airbus qui s’inspirent de l’albatros

Airbus étudie la possibilité de développer des bouts d’ailes articulés, pour mieux adapter l’aérodynamisme de la voilure en cas de turbulences. De quoi également réduire la consommation de carburant.

C’est une nouvelle illustration du biomimétisme appliquée à l’industrie. Airbus a dévoilé mercredi 22 mai à Toulouse, à l’occasion d’un événement dédié aux innovations du groupe, un projet de recherche dénommé Albatross.

Usine Nouvelle

Science & Technology - Astronomy picture of the day : Planet of the Tajinastes

2019 May 25
Planet of the Tajinastes 
Image Credit & Copyright: Daniel Lopez (El Cielo de Canarias)

Explanation: What bizarre planet are these alien creatures from? It's only planet Earth, of course. The planet's home galaxy the Milky Way stretches across a dark sky in the panoramic, fisheye all-sky projection composed with a wide lens. But the imposing forms gazing skyward probably look strange to many denizens of Earth. Found on the Canary Island of Tenerife in the Teide National Park, they are red tajinastes, flowering plants that grow to a height of up to 3 meters. Among the rocks of the volcanic terrain, tajinastes bloom in spring and early summer and then die after a week or so as their seeds mature. A species known as Echium wildpretii, the terrestrial life forms were individually lit by flashlight during the wide-angle exposures.