Science & Technology - Astronomy picture of the day : A Solstice Night in Paris

2019 June 28
A Solstice Night in Paris 
Image Credit & Copyright: Loic Michel

Explanation: The night of June 21 was the shortest night for planet Earth's northern latitudes, so at latitude 48.9 degrees north, Paris was no exception. Still, the City of Light had an exceptionally luminous evening. Its skies were flooded with silvery night shining or noctilucent clouds after the solstice sunset. Hovering at the edge of space, the icy condensations on meteoric dust or volcanic ash are still in full sunlight at the extreme altitudes of the mesophere. Seen at high latitudes in summer months, stunning, wide spread displays of northern noctilucent clouds are now being reported.

Science & Technologie - Avions du futur : L'avion de Northrop Grumman aux ailes hautes et à deux fuselages

Pour augmenter la capacité des avions, pourquoi ne pas mettre deux fuselages plutôt qu'un ? Le concept vient de chez Northrop Grumman et se fait remarquer aussi par ses ailes hautes, c'est-à-dire fixées sur le haut de l'avion. 

© Nasa, Northrop Grumman

Science & Technology - Space : Phoenix prominence eruption

Over a six-hour period on April 21, 2015, NASA's Solar Dyanmics Observatory (SDO) observed a wing-like prominence eruption. SDO views the sun in various wavelengths of the extreme ultravoilet, including 171 (shown in gold) and 304 (shown in orange) angstroms.

Science & Technology - Astronomy picture of the day : Anticrepuscular Rays Converge Opposite the Sun

2019 June 25
Anticrepuscular Rays Converge Opposite the Sun 
Image Credit & Copyright: Juraj Patekar

Explanation: Is there ever anything interesting to see in the direction opposite the Sun? Sometimes there is. Notable items include your own shadow, a shadow of the Moon during a total solar eclipse, a full moon -- in eclipse if the alignment's good enough, a full earth, planets at opposition, glints from planets, the gegenschein from interplanetary dust, the center of a rainbow, hall-of-mountain fogbows, an airplane glory, and something yet again different if your timing, clouds and Sun position are just right. This different effect starts with clouds near the Sun that are causing common crepuscular rays to stream through. In the featured rare image taken from an airplane in mid-April, these beamswere caught converging 180 degrees around, on the opposite side of the sky from the Sun, where they are called anticrepuscular rays. Therefore, it may look like something bright is shining at the antisolar point near the image center, but actually it is reverse-shining because, from your direction, light is streaming in, not out.

Science & Technology - Astronomy picture of the day : Ares 3 Landing Site: The Martian Revisited

2019 June 22
Ares 3 Landing Site: The Martian Revisited Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA

Explanation: This close-up from the Mars Reconnaissance Orbiter's HiRISE camera shows weathered craters and windblown deposits in southern Acidalia Planitia. A striking shade of blue in standard HiRISE image colors, to the human eye the area would probably look grey or a little reddish. But human eyes have not gazed across this terrain, unless you count the eyes of NASA astronauts in the scifi novel The Martian by Andy Weir. The novel chronicles the adventures of Mark Watney, an astronaut stranded at the fictional Mars mission Ares 3 landing site corresponding to the coordinates of this cropped HiRISE frame. For scale Watney's 6-meter-diameter habitat at the site would be about 1/10th the diameter of the large crater. Of course, the Ares 3 landing coordinates are only about 800 kilometers north of the (real life) Carl Sagan Memorial Station, the 1997 Pathfinder landing site.

Music - Video - Vivaldi / Mari Samuelsen : "Estate - presto"

"Estate"

Science & Technologie - Avions du futur : Le Select de Northrop Grumman, un avion économe

Cet avion a l'air très ordinaire mais il ne l'est pas du tout. Pour ce Select (pour Silent Efficient Low Emissions Commercial Transport, en anglais), Northrop Grumman a étudié un appareil de petite capacité - 120 passagers - à très faibles émissions de carbone, réunissant alliages à mémoire de forme, nanotechnologies et matériaux composites en céramique. Le Select pourrait se poser sur des pistes courtes (1.500 mètres) pour utiliser des petits aéroports, ce qui permettrait de déconcentrer le trafic aérien. 

© Nasa, Northrop Grumman Systems Corporation

Science & Technology - Astronomy picture of the day : Sunset Analemma

2019 June 21
Sunset Analemma Image Credit & Copyright: Marcella Giulia Pace

Explanation: Today, the solstice is at 15:54 Universal Time, the Sun reaching the northernmost declination in its yearly journey through planet Earth's sky. A June solstice marks the astronomical beginning of summer in the northern hemisphere and winter in the south. It also brings the north's longest day, the longest period between sunrise and sunset. In fact the June solstice sun is near the top, at the most northern point in the analemma or figure 8 curve traced by the position of the Sun in this composite photo. The analemma was created (video) from images taken every 10 days at the same time from June 21, 2018 and June 7, 2019. The time was chosen to be the year's earliest sunset near the December solstice, so the analemma's lowest point just kisses the unobstructed sea horizon at the left. Sunsets arranged along the horizon toward the right (north) are centered on the sunset at the September equinox and end with sunset at the June solstice.

Science & Technologie - Avions du futur : La double bulle D8 du MIT

Le D8 « double bulle » du Massachusetts Institute of Technology (MIT) propose une cabine large, pour 180 passagers sur ce projet. Les matériaux composites allègent la cellule et les réacteurs, disposés au-dessus de la cellule (ce qui réduit le bruit), sont à double flux mais avec un flux central (chaud, car sortant de la turbine) très étroit, tandis que le flux périphérique (issu du grand ventilateur frontal) est plus large. 

© Nasa, MIT, Aurora Flight Sciences

Science & Technology - Astronomy picture of the day : Spiral Galaxy M96 from Hubble

2019 June 12
Spiral Galaxy M96 from Hubble 
Image Credit: NASA, ESA, Hubble; Processing & Copyright: Leo Shatz

Explanation: Dust lanes seem to swirl around the core of Messier 96 in this colorful, detailed portrait of the center of a beautiful island universe. Of course M96 is a spiral galaxy, and counting the faint arms extending beyond the brighter central region, it spans 100 thousand light-years or so, making it about the size of our own Milky Way. M96, also known as NGC 3368, is known to be about 35 million light-years distant and a dominant member of the Leo I galaxy group. The featured image was taken by the Hubble Space Telescope. The reason for M96's asymmetry is unclear -- it could have arisen from gravitational interactions with other Leo I group galaxies, but the lack of an intra-group diffuse glow seems to indicate few recent interactions. Galaxies far in the background can be found by examining the edges of the picture.

Science & Technology - Astronomy picture of the day : Our Galaxy's Magnetic Center

2019 June 19
Our Galaxy's Magnetic Center 
Image Credit: NASA, SOFIA, Hubble

Explanation: What's the magnetic field like in the center of our Milky Way Galaxy? To help find out, NASA's SOFIA -- an observatory flying in a modified 747 -- imaged the central region with an instrument known as HAWC+.HAWC+ maps magnetism by observing polarized infrared light emitted by elongated dust grains rotating in alignment with the local magnetic field. Now at our Milky Way's center is a supermassive black hole with a hobby of absorbing gas from stars it has recently destroyed. Our galaxy's black hole, though, is relatively quiet compared to the absorption rate of the central black holes in active galaxies. The featured image gives a clue as to why -- a surrounding magnetic field may either channel gas into the black hole -- which lights up its exterior, or forces gas into an accretion-disk holding pattern, causing it to be less active -- at least temporarily. Inspection of the featured image -- appearing perhaps like a surreal mashup of impasto art and gravitational astrophysics -- brings out this telling clue by detailing the magnetic field in and around a dusty ring surrounding Sagittarius A*, the black hole in our Milky Way's center.

Science & Technologie - Avions du futur : Lockheed Martin et son moyen-courrier biréacteur économe

Un concept de Lockheed Martin pour un avion moyen courrier biréacteur à faible consommation. Les réacteurs sont à très large ouverture avec un flux d'air central très étroit. On note surtout la voilure extravagante, plus précisément rhomboédrique. 

© Nasa, Lockheed Martin

Science & tchnology - Astronomy picture of the day : Strawberry Moon over the Temple of Poseidon

2019 June 18
Strawberry Moon over the Temple of Poseidon Image Credit & Copyright: Elias Chasiotis

Explanation: Did you see the full moon last night? If not, tonight's nearly full moon should be almost as good. Because full moons are opposite the Sun, they are visible in the sky when the Sun is not -- which should be nearly all night long tonight, clouds permitting. One nickname for June's full moon is the Strawberry Moon, named for when wild strawberries start to ripen in parts of Earth's northern hemisphere. Different cultures around the globe give this full moondifferent names, though, including Honey Moon and Rose Moon. In the foreground of this featured image, taken yesterday in Cape Sounion, Greece, is the 2,400 year-old Temple of Poseidon. Next month will the 50th anniversary of the time humans first landed on the Moon.

Science & Technology - Astronomy picture of the day : Milky Way over Pyramid of the Feathered Serpent

2019 June 17
Milky Way over Pyramid of the Feathered Serpent 
Image Credit & Copyright: Robert Fedez

Explanation: To see the feathered serpent descend the Mayan pyramid requires exquisite timing. You must visit El Castillo -- in Mexico's Yucatán Peninsula -- near an equinox. Then, during the late afternoon if the sky is clear, the pyramid's own shadows create triangles that merge into the famous illusion of the slithering viper. Also known as the Temple of Kukulkan, the impressive step-pyramid stands 30 meters tall and 55 meters wide at the base. Built up as a series of square terraces by the pre-Columbian civilization between the 9th and 12th century, the structure can be used as a calendar and is noted for astronomical alignments. To see the central band of our Milky Way Galaxy descend overhead the Mayan pyramid, however, requires less exquisite timing. Even the ancient Mayans might have been impressed, though, to know that the exact positions of the Milky Way, Saturn (left) and Jupiter (right) in the featured image give it a time stamp more specific than equinox -- in fact 2019 April 7 at 5 am.

Science & Technology - Astronomy picture of the day : Unusual Mountain Ahuna Mons on Asteroid Ceres

2019 June 16
Unusual Mountain Ahuna Mons on Asteroid Ceres 
Image Credit: Dawn Mission, NASA, JPL-Caltech, UCLA, MPS/DLR/IDA

Explanation: What created this unusual mountain? There is a new theory. Ahuna Mons is the largest mountain on the largest known asteroid in our Solar System, Ceres, which orbits our Sun in the main asteroid belt between Mars and Jupiter. Ahuna Mons, though, is like nothing that humanity has ever seen before. For one thing, its slopes are garnished not with old craters but young vertical streaks. The new hypothesis, based on numerous gravity measurements, holds that a bubble of mud rose from deep within the dwarf planet and pushed through the icy surface at a weak point rich in reflective salt -- and then froze. The bright streaks are thought to be similar to other recently surfaced material such as visible in Ceres' famous bright spots. The featured double-height digital image was constructed from surface maps taken of Ceres in 2016 by the robotic Dawn mission. Successfully completing its mission in 2018, Dawn continues to orbit Ceres even though it has exhausted the fuel needed to keep its antennas pointed toward Earth.

Science & Technology - Astronomy picture of the day : NGC 4676: The Mighty Mice

2019 June 14
NGC 4676: The Mighty Mice 
Image Credit & Copyright: Bruce Waddington

Explanation: These two mighty galaxies are pulling each other apart. Known as The Mice because they have such long tails, each large spiral galaxy has actually passed through the other. Their long tails are drawn out by strong gravitational tides rather than collisions of their individual stars. Because the distances are so large, the cosmic interaction takes place in slow motion -- over hundreds of millions of years. They will probably collide again and again over the next billion years until they coalesce to form a single galaxy. NGC 4676 lies about 300 million light-years away toward the constellation of Bernice's Hair (Coma Berenices) and are likely members of the Coma Cluster of Galaxies. Not often imaged in small telescopes, this wide field of view catches the faint tidal tails several hundred thousand light-years long.

Science & Technology - Astronomy picture of the day : The Colors and Magnitudes of M13

2019 June 13
The Colors and Magnitudes of M13 
Image Credit & Copyright: Tolga Gumusayak, Robert Vanderbei

Explanation: M13 is modestly recognized as the Great Globular Star Cluster in Hercules. A ball of stars numbering in the hundreds of thousands crowded into a region 150 light years across, it lies some 25,000 light-years away. The sharp, color picture of M13 at upper left is familiar to many telescopic imagers. Still, M13's Color vs Magnitude Diagram in the panel below and right, made from the same image data, can offer a more telling view. Also known as aHertzsprung Russell (HR) diagram it plots the apparent brightness of individual cluster stars against color index. The color index is determined for each star by subtracting its brightness (in magnitudes) measured through a red filter from its brightness measured with a blue filter (B-R). Blue stars are hot and red stars are cool so that astronomical color index ranging from bluer to redder follows the relative stellar temperature scale from left (hot) to right (cool). In M13's HR diagram, the stars clearly fall into distinct groups. The broad swath extending diagonally from the bottom right is the cluster's main sequence. A sharp turn toward the upper right hand corner follows the red giant branch while the blue giants are found grouped in the upper left. Formed at the same time, at first M13's stars were all located along the main sequence by mass, lower mass stars at the lower right. Over time higher mass stars have evolved off the main sequence into red, then blue giants and beyond. In fact, the position of the turn-off from the main sequence to the red giant branch indicates the cluster's age at about 12 billion years.

Science & Technology - Astronomy picture of the day : Spiral Galaxy M96 from Hubble

2019 June 12
Spiral Galaxy M96 from Hubble 
Image Credit: NASA, ESA, Hubble; Processing & Copyright: Leo Shatz

Explanation: Dust lanes seem to swirl around the core of Messier 96 in this colorful, detailed portrait of the center of a beautiful island universe. Of course M96 is a spiral galaxy, and counting the faint arms extending beyond the brighter central region, it spans 100 thousand light-years or so, making it about the size of our own Milky Way. M96, also known as NGC 3368, is known to be about 35 million light-years distant and a dominant member of the Leo I galaxy group. The featured image was taken by the Hubble Space Telescope. The reason for M96's asymmetry is unclear -- it could have arisen from gravitational interactions with other Leo I group galaxies, but the lack of an intra-group diffuse glow seems to indicate few recent interactions. Galaxies far in the background can be found by examining the edges of the picture.

Science & Technology - Astronomy picture of the day : The Cave Nebula in Infrared from Spitzer

2019 June 11
The Cave Nebula in Infrared from Spitzer 
Image Credit: NASA, JPL-Caltach, Spitzer Space Telescope

Explanation: What's happening in and around the Cave Nebula? To help find out, NASA's orbiting Spitzer Space Telescope looked into this optically-dark star-forming region in four colors of infrared light. The Cave Nebula, cataloged as Sh2-155, is quite bright in infrared, revealing details not only of internal pillars of gas and dust, but of the illuminating star cluster too - all near the top of the image. The red glow around the Cave's entrance is created by dust heated by bright young stars. To the right is Cepheus B, a star cluster that formed previously from the same cloud of gas and dust. Other interesting stars of Cepheus come to light in infrared as well, including those illuminating an even younger nebula toward the image bottom, and a runaway star pushing a bow shock, tinged in red near the image center. This region spans about 50 light years and lies about 2,500 light years toward the constellation of the King of Aethiopia (Cepheus).

Science & Technology - Astronomy picture of the day : Jupiter Abyss

2019 June 10
Jupiter Abyss 
Image Credit: NASA, Juno, SwRI, MSSS; Processing & License: Gerald Eichstädt & Sean Doran

Explanation: What's that black spot on Jupiter? No one is sure. During the latest pass of NASA's Juno around Jupiter, the robotic spacecraft imaged an usually dark cloud feature informally dubbed the Abyss. Surrounding cloud patterns show the Abyss to be at the center of a vortex. Since dark features on Jupiter's atmosphere tend to run deeper than light features, the Abyss may really be the deep hole that it appears -- but without more evidence that remains conjecture. The Abyss is surrounded by a complex of meandering clouds and other swirling storm systems, some of which are topped by light colored, high-altitude clouds. The featured image was captured last month while Juno passed only about 15,000 kilometers above Jupiter's cloud tops. The next close pass of Juno near Jupiter will be in July.

Science & Technologie - Avions du futur : L'aile volante X48 BWB de Boeing

Boeing et la Nasa ont collaboré sur un projet d'aile volante qui a abouti à la réalisation de prototypes en modèles réduits, les X48 B et C. Le concept est celui de l'aile volante ou BWB pour Blended Wing Body, en anglais, qui signifie « ailes et fuselage fusionnés ». On voit ici une image de synthèse de ce qu'il pourrait être dans le futur. Le principe de l'aile volante présente de nombreuses difficultés (stabilité, vols à faible vitesse, pressurisation...). 

© Nasa, The Boeing Company

Science & Technology - Astronomy picture of the day : On the Beach with Mars

2019 June 8
On the Beach with Mars 
Image Credit & Copyright: Jack Fusco

Explanation: At the end of last year's northern summer, after its dazzling opposition, Mars still shone brightly in the night. The celestial beacon easily attracted the attention of these two night skygazers who stood still for just a while, but long enough to be captured in the sea and night skyscape from Big Sur, planet Earth. Its central bulge near the southwestern horizon, the Milky Way runs through the scene too, while the long exposure also reveals a faint blue bioluminescence blooming in the waves along Pfeiffer Beach. Now much fainter, Mars can be spotted near the western horizon after sunset, but this month Jupiter is near its closest and brightest, reaching its own opposition on June 10. Night skygazers can spot brilliant Jupiter over southern horizons, glaring next to the stars toward the central Milky Way.

Science & Technology - Astronomy picture of the day : The Planet and the Pipe

2019 June 7
The Planet and the Pipe 
Image Credit & Copyright: Alain Maury, Jean-Marc Mari

Explanation: Now posing against our galaxy's rich starfields and nebulae, brilliant planet Jupiter shines in the night sky. Its almost overwhelming glow is near the top of the frame in this colorful telephoto portrait of the central Milky Way. Spanning about 20 degrees on the sky, the scene includes the silhouette of LDN 1773 against the starlight, also know by the popular moniker the Pipe Nebula for its apparent outline of stem and bowl. The Pipe Nebula is part of the galaxy's Ophiuchus dark cloud complex. Located at a distance of about 450 light-years, dense cores of gas and dust within are collapsing to form stars. Approaching its opposition, opposite the Sun in the sky on June 12, Jupiter is only about 36 light-minutes from planet Earth. Fans of dark markings on the sky can probably spot the Snake Nebula below and left of Jupiter's glare.

Science & Technologie - Avions du futur : Le Boeing Sugar Volt, premier avion commercial hybride ? (2/17)

La Nasa a fait plancher les constructeurs aéronautiques sur des concepts d'avions bien plus économes. Boeing a répondu avec ce « Sugar », pour Subsonic Ultra Green Aircraft Research, baptisé Volt. La motorisation serait... hybride, avec une propulsion partiellement électrique, utilisable au décollage, ce qui réduirait le bruit et la consommation de carburant. Celle-ci serait diminuée de 70 % et la réduction globale en énergie (compte tenu des phases électriques) serait de 55 %. On remarque aussi le très grand allongement des ailes (rapport envergure-profondeur). 
© Nasa, The Boeing Company

Science & Technology - Astronomy picture of the day : Messier 63: The Sunflower Galaxy

2019 June 6
Messier 63: The Sunflower Galaxy 
Image Credit & Copyright: Bernard Miller

Explanation: A bright spiral galaxy of the northern sky, Messier 63 is about 25 million light-years distant in the loyal constellation Canes Venatici. Also cataloged as NGC 5055, the majestic island universe is nearly 100,000 light-years across. That's about the size of our own Milky Way Galaxy. Known by the popular moniker, The Sunflower Galaxy, M63 sports a bright yellowish core in this sharp telescopic portrait. Its sweeping blue spiral arms are streaked with cosmic dust lanes and dotted with pink star forming regions. A dominant member of a known galaxy group, M63 has faint, extended features that are likely star streams from tidally disrupted satellite galaxies. M63 shines across the electromagnetic spectrum and is thought to have undergone bursts of intense star formation.

Music - Live - Video - Liberace - Tchaikovsky : "Piano Concerto No 1 in B flat minor"

"Piano Concerto No 1 in B flat minor"

Science & Technology - Astronomy picture of the day : The Interstellar Clouds of Orion

2019 June 5
The Interstellar Clouds of Orion Image Credit & Copyright: Andrew Klinger

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.

Science & Technology - Astronomy picture of the day : SEIS: Listening for Marsquakes

2019 June 4
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.

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.