DESY, Science Communication Lab - Neutrino Associated with Distant Blazar Jet - Astronomy picture of the day - 2018 July 16

Neutrino Associated with Distant Blazar Jet 
Illustration Credit: DESY, Science Communication Lab

Explanation: With equipment frozen deep into ice beneath Earth's South Pole, humanity appears to have discovered a neutrino from far across the universe. If confirmed, this would mark the first clear detection of cosmologically-distant neutrinos and the dawn of an observed association between energetic neutrinos and cosmic rays created by powerful jets emanating from blazing quasars (blazars). Once the Antarctican IceCube detector measured an energetic neutrino in 2017 September, many of humanity's premier observatories sprang into action to try to identify a counterpart in light. And they did. An erupting counterpart was pinpointed by high energy observatories including AGILE,Fermi, HAWC, H.E.S.S., INTEGRAL, NuSTAR, Swift, and VERITAS, which found that gamma-ray blazar TXS 0506+056 was in the right direction and with gamma-rays from a flare arriving nearly coincidental in time with the neutrino. Even though this and other position and time coincidences are statistically strong, astronomers will await other similar neutrino - blazar light associations to be absolutely sure. Pictured here is an artist's drawing of a particle jetemanating from a black hole at the center of a blazar.

La Tribune - L'Eraole, un avion électrique 100% propre - Aéronautique - Video

L'Eraole passera-t-il le cap du prototype ? Pour Raphaël Dinelli, créateur de cet avion électrique multi-hybride 100% propre, les trois prochains mois risquent d'être décisifs. Le 14 juillet, il a décollé de l'aérodrome de la Roche-sur-Yon, en Vendée pour une série de tests et de mesures grandeur nature. Suivront Les Sables-d'Olonne, la Rochelle, Bordeaux, Toulouse, Perpignan, puis la Bretagne et les Hauts-de-Seine, aux alentours du 15 août.

Contrairement au « Solar Impulse » de Bertrand Piccard, qui fonctionne avec le soleil mais aussi des batteries chargées au sol, l'Eraole s'appuie sur une centrale électrique multi-hybride alimentée par le solaire (25%) via les cellules photovoltaïques qui recouvrent les ailes, de l'huile végétale (70%) pour alimenter un moteur thermique et de l'hydrogène produit en vol par hydrolyse.

« C'est cette chaîne de traction qui est une innovation mondiale. On vole avec une énergie totalement propre, contrairement à des batteries dont l'électricité a pu être fournie par une centrale à charbon ou nucléaire. »

Robert Gendler - Rings Around the Ring Nebula - Astronomy picture of the day - 2018 July 15

Rings Around the Ring Nebula 
Image Credit: Hubble, Large Binocular Telescope, Subaru Telescope; Composition & Copyright: Robert Gendler

Explanation: There is much more to the familiar Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This remarkable composite image includes narrowband hydrogen image, visible light emission, and infrared light emission. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layersexpelled from a dying, sun-like star. The Ring Nebula is about 2,000 light-years away toward the musical constellation Lyra.

Padraic Koen - A Nibble on the Sun - Astronomy picture of the day - 2018 July 14

A Nibble on the Sun 
Image Credit & Copyright: Padraic Koen, Adelaide, South Australia

Explanation: The smallest of the three partial solar eclipses during 2018 was just yesterday, Friday, July 13. It was mostly visible over the open ocean between Australia and Antarctica. Still, this video frame of a tiny nibble on the Sunwas captured through a hydrogen-alpha filter from Port Elliott, South Australia, during the maximum eclipse visible from that location. There, the New Moon covered about 0.16 percent of the solar disk. The greatest eclipse, about one-third of the Sun's diameter blocked by the New Moon, could be seen from East Antarctica near Peterson Bank, where the local emperor penguin colony likely had the best view. During this prolific eclipse season, the coming Full Moon will bring a total lunar eclipse on July 27, followed by yet another partial solar eclipse at the next New Moon on August 11.

Miles Lucas - Star Trails and the Bracewell Radio Sundial - Astronomy picture of the day - 2018 July 13

Star Trails and the Bracewell Radio Sundial 
Image Credit & Copyright: Miles Lucas at NRAO

Explanation: Sundials use the location of a shadow to measure the Earth's rotation and indicate the time of day. So it's fitting that this sundial, at the Very Large Array Radio Telescope Observatory in New Mexico, commemorates the history of radio astronomy and radio astronomy pioneer Ronald Bracewell. The radio sundial was constructed using pieces of a solar mapping radio telescope array that Bracewell orginaly built near the Stanford University campus. Bracewell's array was used to contribute data to plan the first Moon landing, its pillars signed by visiting scientists and radio astronomers, including two Nobel prize winners. As for most sundials the shadow cast by the central gnomon follows markers that show the solar time of day, along with solstices and equinoxes. But markers on the radio sundial are also laid out according to local sidereal time. They show the position of the invisible radio shadows of three bright radio sources in Earth's sky, supernova remnant Cassiopeia A, active galaxy Cygnus A, and active galaxy Centaurus A. Sidereal time is just star time, the Earth's rotation as measured with the stars and distant galaxies. That rotation is reflected in this composited hour-long exposure. Above the Bracewell Radio Sundial, the stars trace concentric trails around the north celestial pole.

CEDIC Team at Chilescope - Centaurus A - Astronomy picture of the day - 2018 July 12

Centaurus A 
Image Credit & Copyright: CEDIC Team at Chilescope, Processing - Bernhard Hubl

Explanation: Only 11 million light-years away, Centaurus A is the closest active galaxy to planet Earth. Spanning over 60,000 light-years, the peculiar elliptical galaxy also known as NGC 5128, is featured in this sharp telescopic view.Centaurus A is apparently the result of a collision of two otherwise normal galaxies resulting in a fantastic jumble of star clusters and imposing dark dust lanes. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. As in other active galaxies, that process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A.

Science et Vie - Ciel de juillet : une éclipse totale sous le signe de mars - Espace

Le 27 juillet 2018 restera dans les annales astronomiques comme la nuit où une éclipse totale de Lune a eu lieu au moment où Mars était au plus près de la Terre : un spectacle prodigieux, à ne manquer sous aucun prétexte.

Le ciel de juillet sera, comme ce mois de juin, dominé par les planètes : Vénus au couchant, puis Jupiter en début de soirée, enfin Saturne et Mars au cœur de la nuit... Une magnifique et brillante horlogerie cosmique, réglée par le tic-tac plus rapide de la Lune, qui croisera Vénus le 15 et le 16, Jupiter le 20, Saturne le 24 et enfin Mars... le 27 juillet.

Sauf que par un extraordinaire hasard du calendrier cosmique, cette nuit du 27 verra la Pleine Lune, totalement éclipsée, luire aux côtés de la planète Mars, qui brillera alors d'un éclat exceptionnel. En effet, Mars sera alors au plus près de la Terre, à seulement 57 millions de kilomètres, ce qui n'arrive que tous les quinze ans. La magnitude - c'est-à-dire l'éclat, dans le langage des astronomes - de Mars sera de -2.8, l'astre, véritable rubis céleste, brillera plus de dix fois plus que les brillantes étoiles qui l'environnent, comme Antarès, Altaïr, Arcturus, Véga ou Deneb.

Jean-Luc Dauvergne - Noctilucent Clouds over Paris Fireworks - Astronomy picture of the day - 2018 July 11

Noctilucent Clouds over Paris Fireworks 
Video Credit & Copyright: Jean-Luc Dauvergne (Ciel et Espace);

Explanation: It's northern noctilucent cloud season -- perhaps a time to celebrate! Composed of small ice crystals forming only during specific conditions in the upper atmosphere, noctilucent clouds may become visible at sunset during late summer when illuminated by sunlight from below. Noctilucent clouds are the highest clouds known and now established to be polar mesospheric clouds observed from the ground. Although observed with NASA's AIM satellitesince 2007, much about noctilucent clouds remains unknown and so a topic of active research. The featured time-lapse video shows expansive and rippled noctilucent clouds wafting over Paris, France, during a post-sunset fireworks celebration on Bastille Day in 2009 July. This year, several locations are already reporting especially vivid displays of noctilucent clouds.

John Chumack - Road to Mars - Astronomy picture of the day - 2018 July 9

Road to Mars 
Image Credit & Copyright: John Chumack

Explanation: What's that light at the end of the road? Mars. This is a good month to point out Mars to your friends and family because our neighboring planet will not only be its brightest in 15 years, it will be visible for much of night.During this month, Mars will be about 180 degrees around from the Sun, and near the closest it ever gets to planet Earth. In terms of orbits, Mars is also nearing the closest point to the Sun in its elliptical orbit, just as Earth moves nearly between it and the Sun -- an alignment known as perihelic opposition. In terms of viewing, orange Mars will rise in the east just as the Sun sets in the west, on the opposite side of the sky. Mars will climb in the sky during the night, reach its highest near midnight, and then set in the west just as the Sun begins to rise in the east. The red planet was captured setting beyond a stretch of road in Arches National Park in mid-May near Moab, Utah, USA.

Nasa : The Extraordinary Spiral in LL Pegasi - Astronomy picture of the day - 2018 July 8

The Extraordinary Spiral in LL Pegasi 
Image Credit: NASA, ESA, Hubble, HLA; Processing & Copyright: Domingo Pestana & Raul Villaverde

Explanation: What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected. The huge spiral spans about a third of a light year across and, winding four or five complete turns, has a regularity that is without precedent. Given the expansion rate of the spiral gas, a new layer must appear about every 800 years, a close match to the time it takes for the two stars to orbit each other. The star system that created it is most commonly known as LL Pegasi, but also AFGL 3068. The unusual structure itself has been cataloged as IRAS 23166+1655. The featured image was taken in near-infrared light by the Hubble Space Telescope. Why the spiral glows is itself a mystery, with a leading hypothesis being illumination by light reflected from nearby stars.