ASTRONOMY - Perseids and MAGIC

 2022 August 11

Perseids and MAGIC
Image Credit & Copyright: Urs Leutenegger

Explanation: On August 11, 2021 a multi-mirror, 17 meter-diameter MAGIC telescope reflected this starry night sky from the Roque de los Muchachos European Northern Observatory on the Canary Island of La Palma. MAGIC stands for Major Atmospheric Gamma Imaging Cherenkov. The telescopes can see the brief flashes of optical light produced in particle air showers as high-energy gamma rays impact the Earth's upper atmosphere. To the dark-adapted eye the mirror segments offer a tantalizing reflection of stars and nebulae along the plane of our Milky Way galaxy. But directly behind the segmented mirror telescope, low on the horizon, lies the constellation Perseus. And on that date the dramatic composite nightscape also captured meteors streaming from the radiant of the annual Perseid meteor shower. This year the Perseid shower activity will again peak around August 13 but perseid meteors will have to compete with the bright light of a Full Moon.

ASTRONOMY - Dust Clouds of the Pacman Nebula

 2022 August 10

Dust Clouds of the Pacman Nebula
Image Credit & Copyright: Douglas J. Struble (Future World Media)

Explanation: Stars can create huge and intricate dust sculptures from the dense and dark molecular clouds from which they are born. The tools the stars use to carve their detailed works are high energy light and fast stellar winds. The heat they generate evaporates the dark molecular dust as well as causing ambient hydrogen gas to disperse and glow red. Pictured here, a new open cluster of stars designated IC 1590 is nearing completion around the intricate interstellar dust structures in the emission nebula NGC 281, dubbed the Pac-man Nebula because of its overall shape. The dust cloud on the upper left is classified as a Bok Globule as it may gravitationally collapse and form a star -- or stars. The Pacman Nebula lies about 10,000 light years away toward the constellation of Cassiopeia.

SANTé/MéDECINE - Les vertus du cannabidiol (CBD)

Difficile de passer à côté de la popularité du cannabidiol. Depuis pas mal d’années maintenant, cet extrait issu du chanvre voit sa notoriété monter en flèche, notamment car il se présente sous diverses formes et offre des vertus non négligeables. Parmi elles, la capacité à relaxer et détendre la personne qui en consomme. Mais pas seulement : problèmes d’articulations, douleurs musculaires, manque de sommeil, crises d’angoisse à répétition…consommé régulièrement et à dose raisonnable, le CBD peut avoir un impact positif sur de nombreux problèmes que l’on rencontre au quotidien, jour et nuit. Pour tester les effets procurés par le CBD, partez à sa rencontre. Dans les grandes lignes l'huile composée à 12% de CBD et quasiment dépourvue de THC, aide à se défaire de l’anxiété et du stress, et de retrouver un sommeil profond, le tout naturellement et sans addiction.

MUSIQUE CLASSIQUE - Frederic Chopin - Tristesse

"Tristesse"

ASTROPHOTOGRAPHIES - La nébuleuse de la Tête de Cheval

Portrait haut en couleur et détaillé de la célèbre nébuleuse de la Tête de Cheval située près de la ceinture de la constellation d'Orion, en 2014, par Bill Snyder (États-Unis). L'astrophotographe a cumulé quelque 13 heures d'exposition au foyer de son télescope de 432 mm installé dans les montagnes de la Sierra Nevada en Californie. C'est un dense nuage de poussière en mouvement qui dessine la silhouette de cet animal devant les grandes draperies d'une partie du nuage moléculaire d'Orion.  

Cette nébuleuse obscure est distante d'environ 1.500 années-lumière de nous.

© Bill Snyder, Flickr

FuturaSciences

ASTRONOMY - Leaving Earth

 022 August 9

Leaving Earth
Video Credit: NASA/JHU Applied Physics Lab/Carnegie Inst. Washington

Explanation: What it would look like to leave planet Earth? Such an event was recorded visually in great detail by the MESSENGER spacecraft as it swung back past the Earth in 2005 on its way in toward the planet Mercury. Earth can be seen rotating in this time-lapse video, as it recedes into the distance. The sunlit half of Earth is so bright that background stars are not visible. The robotic MESSENGER spacecraft is now in orbit around Mercury and has recently concluded the first complete map of the surface. On occasion, MESSENGER has continued to peer back at its home world. MESSENGER is one of the few things created on the Earth that will never return. At the end of its mission MESSENGER crashed into Mercury's surface.

ASTRONOMY - The Lagoon Nebula without Stars

 2022 August 8

The Lagoon Nebula without Stars
Image Credit & Copyright: Sameer Dhar

Explanation: Ridges of glowing interstellar gas and dark dust clouds inhabit the turbulent, cosmic depths of the Lagoon Nebula. Also known as M8, the bright star forming region is about 5,000 light-years distant. But it still makes for a popular stop on telescopic tours of the constellation Sagittarius, toward the center of our Milky Way Galaxy. Dominated by the telltale red emission of ionized hydrogen atoms recombining with stripped electrons, this stunning, deep view of the Lagoon is nearly 100 light-years across. Right of center, the bright, compact, hourglass shape is gas ionized and sculpted by energetic radiation and extreme stellar winds from a massive young star. In fact, although digitally removed from the featured image, the many bright stars of open cluster NGC 6530 drift within the nebula, just formed in the Lagoon several million years ago.

ASTRONOMY - Meteor before Galaxy

 2022 August 7

Meteor before Galaxy
Image Credit & Copyright: Fritz Helmut Hemmerich

Explanation: What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a small pebble from deep space crossed right in front of our Milky Way Galaxy's far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field. The meteor flared several times while braking violently upon entering Earth's atmosphere. The green color was created, at least in part, by the meteor's gas glowing as it vaporized. Although the exposure was timed to catch a Perseid meteor, the orientation of the imaged streak seems a better match to a meteor from the Southern Delta Aquariids, a meteor shower that peaked a few weeks earlier. Not coincidentally, the Perseid Meteor Shower peaks later this week, although this year the meteors will have to outshine a sky brightened by a nearly full moon.

MERVEILLEUX MONDE SOUS-MARIN - Souffleur à selle noire

 

Atoll de Fakarava. Réserve de la biosphère.

Souffleur à selle noire (Canthigaster valentini).

© Photographe Alexis Rosenfeld

FuturaSciences

ASTROPHOTOGRAPHIE - Terre et Espace

« Terre et espace », très belle composition de James Woodend (Royaume-Uni). Paysage embrasé par une aurore, le feu et la glace se mirent dans les eaux paisibles qui bordent le glacier Vatnajökull, au sud de l'Islande.

© James Woodend, Flickr