ASTRONOMY - A Paper Moon Solar Eclipse

 2021 June 28

A Paper Moon Solar Eclipse
Image Credit & Copyright: Wang Letian (Eyes at Night)

Explanation: It may look like a paper Moon. Sailing past a canvas Sun. But those are not cardboard clouds. And it's not make believe.  The featured picture of an orange colored sky is real -- a digital composite of two exposures of the solar eclipse that occurred earlier this month. The first exposure was taken with a regular telescope that captured an overexposed Sun and an underexposed Moon, while the second image was taken with a solar telescope that captured details of the chromosphere of the background Sun. The Sun's canvas-like texture was brought up by imaging in a very specific shade of red emitted by hydrogen. Several prominences can be seen around the Sun's edge. The image was captured just before sunset from Xilingol, Inner Mongolia, China. It's also not make-believe to imagine that the Moon is made of dense rock, the Sun is made of hot gas, and clouds are made of floating droplets of water and ice.

ASTRONOMY - Pixels in the Sun

 2021 June 26

Pixels in the Sun
Image Credit & Copyright: Wang Letian (Eyes at Night)

Explanation: These two panels, composed of video frames made with a safe solar telescope and hydrogen alpha filter, show remarkably sharp details on the solar disk and giant prominences along the Sun's edge on June 6 (top) and June 18. Taken from Beijing, China, they also show a transit of the International Space Station and China's new Tiangong Space Station in silhouette against the bright Sun. The International Space Station is near center in the bottom panel, crossing the solar disk left of bright active region AR2833 and below a large looping solar filament. The Chinese space station is below solar active region AR2827 and right of center in the top panel, seen as a smaller, combined "+" and "-" shape. The pictures of the transiting orbital outposts were taken with the same equipment and at the same pixel scale, with the International Space Station some 492 kilometers away. The Chinese space station was over 400 kilometers from the camera.

ASTRONOMY - Messier 99

 2021 June 24

Messier 99
Image Credit: NASA, ESA, Hubble, Janice Lee; Processing & Copyright: Leo Shatz

Explanation: Grand design spiral galaxy Messier 99 looks majestic on a truly cosmic scale. This recently processed full galaxy portrait stretches over 70,000 light-years across M99. The sharp view is a combination of ultraviolet, visible, and infrared image data from the Hubble Space Telescope. About 50 million light-years distant toward the well-groomed constellation Coma Bernices, the face-on spiral is a member of the nearby Virgo Galaxy Cluster. Also cataloged as NGC 4254, a close encounter with another Virgo cluster member has likely influenced the shape of its well-defined, blue spiral arms.

ASTRONOMY - HD 163296: Jet from a Star in Formation

 2021 June 22

HD 163296: Jet from a Star in Formation
Image Credit: Visible: VLT/MUSE (ESO); Radio: ALMA (ESO/NAOJ/NRAO)

Explanation: How are jets created during star formation? No one is sure, although recent images of the young star system HD 163296 are quite illuminating. The central star in the featured image is still forming but seen already surrounded by a rotating disk and an outward moving jet. The disk is shown in radio waves taken by the Atacama Large Millimeter Array (ALMA) in Chile, and show gaps likely created by the gravity of very-young planets. The jet, shown in visible light taken by the Very Large Telescope (VLT, also in Chile), expels fast-moving gas -- mostly hydrogen -- from the disk center. The system spans hundreds of times the Earth-Sun distance (au). Details of these new observations are being interpreted to bolster conjectures that the jets are generated and shaped, at least in part, by magnetic fields in the rotating disk. Future observations of HD 163296 and other similar star-forming systems may help fill in details.

AERONAUTIQUE - Le F-8 Crusader

"F-8 Crusader"

ASTRONOMY - Northern Summer Twilight

 2021 June 19

Northern Summer Twilight
Image Credit & Copyright: Justin Anderson

Explanation: Nights grow shorter and days grow longer as the summer solstice approaches in the north. Usually seen at high latitudes in summer months, noctilucent or night shining clouds begin to make their appearance. Drifting near the edge of space about 80 kilometers above the Earth's surface, these icy clouds were still reflecting the sunlight on June 14. Though the Sun was below the horizon as seen north of Forrest, Manitoba, Canada, they were caught in a single exposure of a near midnight twilight sky. Multiple exposures of the foreground track the lower altitude flash of fireflies, another fleeting apparition shining in the summer night.

ASTRONOMY - Devil Horns from a Ring of Fire

 2021 June 18

Devil Horns from a Ring of Fire
Image Credit & Copyright: Madhup Rathi

Explanation: Atmospheric refraction flattened the solar disk and distorted its appearance in this telescopic view of an Atlantic sunrise on June 10. From Belmar, New Jersey on the US east coast, the scene was recorded at New Moon during this season's annular solar eclipse. The Moon in partial silhouette gives the rising Sun its crescent shape reminding some of the horns of the devil (or maybe a flying canoe ...). But at its full annular phase this eclipsed Sun looked like a ring of fire in the heavens. June's annular solar eclipse followed on the heels of the total lunar eclipse of late May's Full Moon. Of course, that total lunar eclipse was a dramatic red Blood Moon eclipse.

ASTRONOMY - NGC 6888: The Crescent Nebula

 2021 June 17

NGC 6888: The Crescent Nebula
Image Credit & Copyright: Joe Navara, Glenn Clouder, Russell Discombe

Explanation: NGC 6888, also known as the Crescent Nebula, is a about 25 light-years across blown by winds from its central, bright, massive star. A triumvirate of astroimagers ( Joe, Glenn, Russell) created this sharp portrait of the cosmic bubble. Their telescopic collaboration collected over 30 hours of narrow band image data isolating light from hydrogen and oxygen atoms. The oxygen atoms produce the blue-green hue that seems to enshroud the detailed folds and filaments. Visible within the nebula, NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away.

PRATIQUE/POURQUOI - Pourquoi y a-t-il des "trous d'air" en avion ?

L'air qui nous entoure n'est pas homogène. Il y a des masses chaudes (qui ont tendance à monter) et des masses froides (qui ont tendance à descendre). Elles évoluent en permanence.

Un avion qui vole relativement vite par rapport aux masses d'air rencontre donc dans sa trajectoire des masses d'air qui montent ou qui descendent. Ses passagers ressentent donc les évolutions vers le haut ou le bas de l'appareil (communément appelées ''trous d'air'').

Ces phénomènes se rencontrent surtout près et dans les complexes orageux et c'est pourquoi il est recommandé par l'équipage d'attacher sa ceinture de sécurité alors qu'on est loin de l'arrivée afin de ne pas finir son sandwitch collé au plafond.

ASTRONOMY - Scorpius Enhanced

 2021 June 16

Scorpius Enhanced
Image Credit & Copyright: Stefan Lenz

Explanation: If Scorpius looked this good to the unaided eye, humans might remember it better. Scorpius more typically appears as a few bright stars in a well-known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, a dark sky, and some sophisticated image processing. The resulting digitally-enhanced image shows many breathtaking features. Diagonal across the image right is part of the plane of our Milky Way Galaxy. Visible there are vast clouds of bright stars and long filaments of dark and intricate dust. Rising vertically on the image left are dark dust bands known as the Dark River. Several of the bright stars on the left are part of Scorpius' head and claws, and include the bright star Antares. Numerous red emission nebulas, blue reflection nebulas, and dark filaments became visible as the deep 17-hour expo image developed. Scorpius appears prominently in southern skies after sunset during the middle of the year.

I-PHONE ASTUCES - Désactiver l’accusé de lecture

Désactiver l’accusé de lecture « lu » dans les messages Savez-vous que tout le monde peut voir si vous avez bien reçu et lu un iMessage ? Pour désactiver l'accusé de réception et de lecture, allez sur Réglages > Messages et désactivez "Confirmation de lecture".

ASTRONOMY - Zhurong: New Rover on Mars

 2021 June 15

Zhurong: New Rover on Mars
Image Credit: China National Space Administration

Explanation: There's a new rover on Mars. In mid-May, China's Tianwen-1 mission delivered the Zhurong rover onto the red planet. As Mars means Planet of Fire in Chinese, the Zhurong rover's name means, roughly, God of Fire in Chinese mythology. Zhurong landed in northern Utopia Planitia, the largest known impact basin in the Solar System, and an area reported to have much underground ice. Among many other scientific instruments, Zhurong carries ground-penetrating radar that can detect ice buried even 100-meters deep. Car-sized Zhurong is pictured here next to its landing base. The image was snapped by a remote camera deployed by the rolling rover. Zhurong's planned 90-day mission includes studying the geology, soil, and atmosphere of Mars in Utopia Planitia.

AERONAUTIQUE - Ces merveilleux fous volants dans leur drôle de machine

AUTOMOBILE - Jaguar XJ220

"Jaguar XJ220"

ASTRONOMY - Eclipse du soleil vue depuis Montreal

ASTRONOMY - Eclipse Flyby

 2021 June 11

Eclipse Flyby
Image Credit & Copyright: Zev Hoover, Christian Lockwood, and Zoe Chakoian

Explanation: On June 10 a New Moon passed in front of the Sun. In silhouette only two days after reaching apogee, the most distant point in its elliptical orbit, the Moon's small apparent size helped create an annular solar eclipse. The brief but spectacular annular phase of the eclipse shows a bright solar disk as a ring of fire when viewed along its narrow, northerly shadow track across planet Earth. Cloudy early morning skies along the US east coast held gorgeous views of a partially eclipsed Sun though. Rising together Moon and Sun are captured in a sequence of consecutive frames near maximum eclipse in this digital composite, seen from Quincy Beach south of Boston, Massachusetts. The serendipitous sequence follows the undulating path of a bird in flight joining the Moon in silhouette with the rising Sun.

I-PHONE ASTUCES - Comment améliorer la luminosité

Augmenter la luminosité quand vous prenez une photo Savez-vous qu'il est possible d'améliorer la luminosité quand vous prenez une photo ? Cette fonction est bien pratique si vous faites une photo dans un endroit sombre avec peu de lumière. Ou si, à l'inverse, vous voulez diminuer la luminosité pour une photo prise en contre-jour. Pour cela, touchez l'écran n'importe où, puis glissez votre doigt vers le haut pour augmenter la luminosité ou vers le bas pour la baisser.

AERONAUTIQUE - Drôles de machines - Zoom Climb

ASTRONOMY - A Total Lunar Eclipse Corona

 2021 June 9

A Total Lunar Eclipse Corona
Image Credit & Copyright: Helmut Eder

Explanation: This moon appears multiply strange. This moon was a full moon, specifically called a Flower Moon at this time of the year. But that didn't make it strange -- full moons occur once a month (moon-th). This moon was a supermoon, meaning that it reached its full phase near its closest approach to the Earth in its slightly elliptical orbit. Somewhat strange, a supermoon appears a bit larger and brighter than the average full moon -- and enables it to be called a Super Flower Moon.  This moon was undergoing a total lunar eclipse. An eclipsed moon can look quite strange, being dark, unevenly lit, and, frequently, red -- sometimes called blood red. Therefore, this moon could be called a Super Flower Blood Moon. This moon was seen through thin clouds. These clouds created a faint corona around the moon, making it look not only strange, but colorful. This moon was imaged so deeply that the heart of the Milky Way galaxy, far in the background, was visible to its lower right. This moon, this shadow, this galaxy and these colors were all captured last month near Cassilis, NSW, Australia -- with a single shot. (Merged later with two lower shots that better capture the Milky Way.)

ASTRONOMY - A Bright Nova in Cassiopeia

 2021 June 7

A Bright Nova in Cassiopeia
Image Credit & Copyright: Chuck Ayoub

Explanation: What’s that new spot of light in Cassiopeia? A nova. Although novas occur frequently throughout the universe, this nova, known as Nova Cas 2021 or V1405 Cas, became so unusually bright in the skies of Earth last month that it was visible to the unaided eye. Nova Cas 2021 first brightened in mid-March but then, unexpectedly, became even brighter in mid-May and remained quite bright for about a week. The nova then faded back to early-May levels, but now is slightly brightening again and remains visible through binoculars. Identified by the arrow, the nova occurred toward the constellation of Cassiopeia, not far from the Bubble Nebula. A nova is typically caused by a thermonuclear explosion on the surface of a white dwarf star that is accreting matter from a binary-star companion -- although details of this outburst are currently unknown. Novas don't destroy the underlying star, and are sometimes seen to recur. The featured image was created from 14 hours of imaging from Detroit, Michigan, USA. Both professional and amateur astronomers will likely continue to monitor Nova Cas 2021 and hypothesize about details of its cause.

ASTRONOMY - A Distorted Sunrise Eclipse

 2021 June 6

A Distorted Sunrise Eclipse
Image Credit & Copyright: Elias Chasiotis

Explanation: Yes, but have you ever seen a sunrise like this? Here, after initial cloudiness, the Sun appeared to rise in two pieces and during partial eclipse, causing the photographer to describe it as the most stunning sunrise of his life. The dark circle near the top of the atmospherically-reddened Sun is the Moon -- but so is the dark peak just below it. This is because along the way, the Earth's atmosphere had an inversion layer of unusually warm air which acted like a gigantic lens and created a second image. For a normal sunrise or sunset, this rare phenomenon of atmospheric optics is known as the Etruscan vase effect. The featured picture was captured in December 2019 from Al Wakrah, Qatar. Some observers in a narrow band of Earth to the east were able to see a full annular solar eclipse -- where the Moon appears completely surrounded by the background Sun in a ring of fire. The next solar eclipse, also an annular eclipse for well-placed observers, will occur later this week on June 10.

ASTRONOMY - The Shining Clouds of Mars

 2021 June 5

The Shining Clouds of Mars
Image Credit: NASA, JPL-Caltech, MSSS

Explanation: The weathered and layered face of Mount Mercou looms in the foreground of this mosaic from the Curiosity Mars rover's Mast Camera. Made up of 21 individual images the scene was recorded just after sunset on March 19, the 3,063rd martian day of Curiosity's on going exploration of the Red Planet. In the martian twilight high altitude clouds still shine above, reflecting the light from the Sun below the local horizon like the noctilucent clouds of planet Earth. Though water ice clouds drift through the thin martian atmosphere, these wispy clouds are also at extreme altitudes and could be composed of frozen carbon dioxide, crystals of dry ice. Curiosity's Mast Cam has also imaged iridescent or mother of pearl clouds adding subtle colors to the martian sky.

AERONAUTIQUE - Drôles de machines - L'hélice et la vitesse

"L'hélice et la vitesse"

TELEPORTATION - Des physiciens réalisent une téléportation quantique entre deux puces informatiques

Des physiciens de l'Université de Bristol (Royaume-Uni) et l’Université technique du Danemark (DTU) ont réussi à effectuer une téléportation quantique entre deux puces informatiques de silicium, assurent-ils dans un article de la revue Nature Physics, publié le 23 décembre 2019.

En d’autres termes, des informations ont bel et bien été transmises instantanément entre les cartes… mais pas à travers des connexions physiques classiques. L’échange s’est effectué par “enchevêtrement ou intrication quantique” — c’est-à-dire en reliant deux particules à travers l’espace, selon les principes de la physique quantique.

Des particules qui partagent un même état

L'intrication quantique est un phénomène fondamental bien mystérieux. Il avait déjà été décrit par Albert Einstein dans les années 1930, sous le nom d’ “action fantasmagorique”. En théorie, il peut fonctionner sur n'importe quelle distance, car il se base sur le lien inextricable entre deux particules.

En fait, lorsque deux particules sont intriquées, elles partagent les mêmes propriétés et ne forment plus qu’un système unique. Ainsi, en observant l’une d'entre elles, on en apprend plus sur l’autre — notamment où elle se trouve. Et dans le cas de cette expérience, sur une puce informatique distincte.

Nous avons pu démontrer un lien d'enchevêtrement de haute qualité entre deux puces en laboratoire, où les photons sur l'une ou l'autre puce partagent un seul état quantique, explique dans un communiqué le physicien Dan Llewellyn. Chaque puce a ensuite été entièrement programmée pour effectuer une gamme de démonstrations qui utilisent l'enchevêtrement.

ASTRONOMY - Millions of Stars in Omega Centauri

 2021 June 3

Millions of Stars in Omega Centauri
Image Credit & Copyright: Ignacio Diaz Bobillo

Explanation: Globular star cluster Omega Centauri, also known as NGC 5139, is some 15,000 light-years away. The cluster is packed with about 10 million stars much older than the Sun within a volume about 150 light-years in diameter. It's the largest and brightest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way. Omega Centauri's red giant stars (with a yellowish hue) are easy to pick out in this sharp, color telescopic view.

NUCLEAIRE - Le soleil artificiel chinois

En décembre dernier, un tokamak chinois à peine allumé, le HL-2M, avait atteint les 150 millions de degrés Celsius. Ce vendredi 28 mai, un autre tokamak chinois, l'Experimental Advanced Superconducting Tokamak (East) a fait mieux. Il a atteint 160 millions de degrés Celsius. Mais il a surtout réussi à maintenir son plasma à une température de plus de 120 millions de degrés Celsius pendant 101 secondes.

Un tokamak -- l'acronyme vient du russe --, c'est un engin imaginé par les physiciens pour produire de l'énergie par fusion nucléaire. Une énergie réputée propre -- sans émission de gaz à effet de serre ni production de déchets radioactifs à haute activité et à vie longue --, sûre et illimitée. Encore faut-il que la température du plasma qui l'alimente soit suffisamment élevée. Et qu'elle puisse être maintenue à un niveau stable pendant une longue période de temps.

L'objectif semble se rapprocher. Grâce au tokamak chinois appelé Experimental Advanced Superconducting Tokamak (East). Il y a quelques jours, au cœur de ce véritable soleil artificiel, la température du plasma est montée à quelque 120 millions de degrés Celsius pour y rester pendant 101 secondes. Pendant 20 petites secondes, le réacteur à fusion nucléaire expérimental a même atteint les 160 millions de degrés Celsius.

Futura Sciences - France

GEOLOGIE - Un énorme gouffre s'est ouvert et grandit au Mexique...

Un gouffre ou doline s'est ouvert et n'arrête pas de s'agrandir au Mexique!

AERONAUTIQUE - Drôles de Machines - Le Me 1 6 3 Komet

"Me 1 6 3 Komet"

ASTRONOMY - Starlink over Orion

 2021 June 1

Starlink over Orion
Image Credit: Amir H. Abolfath

Explanation: What are those streaks across Orion? Most are reflections of sunlight from numerous Earth-orbiting Starlink satellites. Appearing by eye as a series of successive points floating across a twilight sky, the increasing number of SpaceX Starlink communication satellites are causing concern among many astronomers. On the positive side, Starlink and similar constellations make the post-sunset sky more dynamic, satellite-based global communications faster, and help provide digital services to currently underserved rural areas. On the negative side, though, these low Earth-orbit satellites make some deep astronomical imaging programs more difficult, in particular observing programs that need images taken just after sunset and just before dawn. Planned future satellite arrays that function in higher orbits may impact investigations of the deep universe planned for large ground-based telescopes at any time during the night. The featured picture, taken in 2019 December, is a digital combination of over 65 3-minutes exposures, with some images taken to highlight the background Orion Nebula, while others to feature the passing satellites.