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12/11/2021

ASTRONOMY - Night of the Perseids

2021 September 28

Night of the Perseids
Video Credit & Copyright: Vikas Chander & Dorje Angchuk; Music: Tea Time via PremiumBeat

Explanation: Have you ever experienced a meteor shower? To help capture the wonder, a video was taken during the peak of the recent Perseid meteor shower above the Indian Astronomical Observatory in HanleIndia, high up in the Himalayan mountains. Night descends as the video begins, with the central plane of our Milky Way Galaxy approaching from the left and Earth-orbiting satellites zipping by overhead. During the night, the flash of meteors that usually takes less than a second is artificially extended. The green glow of most meteors is typically caused by vaporizing nickel. As the video continues, Orion rises and meteors flare above the 2-meter Himalayan Chandra Telescope and the seven barrels of the High Energy Gamma Ray Telescope (Hagar). The 2 minute 30 second movie ends with the Sun rising, preceded by a false dawn of zodiacal light

11/11/2021

ASTRONOMY - Video of a Green Flash

2021 November 10

Video of a Green Flash
Video Credit & Copyright: Paolo Lazzarotti

Explanation: Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green. The effect is typically visible only from locations with a low, distant horizon, and lasts just a few seconds. A green flash is also visible for a rising Sun, but takes better timing to spot. A dramatic green flash was caught on video last month as the Sun set beyond the Ligurian Sea from TuscanyItaly. The second sequence in the featured video shows the green flash in real time, while the first is sped up and the last is in slow motion. The Sun itself does not turn partly green -- the effect is caused by layers of the Earth's atmosphere acting like a prism

ASTRONOMY - NGC 1333: Stellar Nursery in Perseus

 2021 November 11

See Explanation.  Clicking on the picture will download
the highest resolution version available.

NGC 1333: Stellar Nursery in Perseus
Image Credit & Copyright: Michael Sherick

Explanation: NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud. This telescopic close-up spans about two full moons on the sky or just over 15 light-years at the estimated distance of NGC 1333. It shows details of the dusty region along with telltale hints of contrasty red emission from Herbig-Haro objects, jets and shocked glowing gas emanating from recently formed stars. In fact, NGC 1333 contains hundreds of stars less than a million years old, most still hidden from optical telescopes by the pervasive stardust. The chaotic environment may be similar to one in which our own Sun formed over 4.5 billion years ago.

09/11/2021

ASTRONOMY - A Waterfall and the Milky Way

 2021 November 1

The picture shows a waterfall under a night sky 
dominated by the arch of our Milky Way Galaxy. 
Please see the explanation for more detailed information.

A Waterfall and the Milky Way
Image Credit & Copyright: Xie Jie

Explanation: The dream was to capture both the waterfall and the Milky Way together. Difficulties included finding a good camera location, artificially illuminating the waterfall and the surrounding valley effectively, capturing the entire scene with numerous foreground and background shots, worrying that fireflies would be too distracting, keeping the camera dry, and avoiding stepping on a poisonous snake. Behold the result -- captured after midnight in mid-July and digitally stitched into a wide-angle panorama. The waterfall is the picturesque Zhulian waterfall in the Luoxiao Mountains in eastern Hunan ProvinceChina. The central band of our Milky Way Galaxy crosses the sky and shows numerous dark dust filaments and colorful nebulas. Bright stars dot the sky -- all residing in the nearby Milky Way -- including the Summer Triangle with bright Vega visible above the Milky Way's arch. After capturing all 78 component exposures for you to enjoy, the photographer and friends enjoyed the view themselves for the rest of the night.

08/11/2021

ASTRONOMY - A Filament Leaps from the Sun

 2021 November 8

A Filament Leaps from the Sun
Video Credit & Copyright: Stéphane Poirier

Explanation: Why, sometimes, does part of the Sun's atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun's surface. Regions of strong surface magnetism, known as active regions, are usually marked by dark sunspots. Active regions can channel charged gas along arching or sweeping magnetic fields -- gas that sometimes falls backsometimes escapes, and sometimes not only escapes but impacts our Earth. The featured one-hour time-lapse video -- taken with a small telescope in France -- captured an eruptive filament that appeared to leap off the Sun late last month. The filament is huge: for comparison, the size of the Earth is shown on the upper left. Just after the filament lifted off, the Sun emitted a powerful X-class flare while the surface rumbled with a tremendous solar tsunami. A result was a cloud of charged particles that rushed into our Solar System but mostly missed our Earth -- this time. However, enough solar plasma did impact our Earth's magnetosphere to create a few faint auroras.

07/11/2021

ASTRONOMY - A Rorschach Aurora

 2021 October 30

See Explanation.  Clicking on the picture will download
the highest resolution version available.

A Rorschach Aurora
Image Credit & Copyright: Göran Strand

Explanation: If you see this as a monster's face, don't panic. It's only pareidolia, often experienced as the tendency to see faces in patterns of light and shadow. In fact, the startling visual scene is actually a 180 degree panorama of Northern Lights, digitally mirrored like inkblots on a folded piece of paper. Frames used to construct it were captured on a September night from the middle of a waterfall-crossing suspension bridge in Jamtland, Sweden. With geomagnetic storms triggered by recent solar activity, auroral displays could be very active at planet Earth's high latitudes in the coming days. But if you see a monster's face in your own neighborhood tomorrow night, it might just be Halloween.

06/11/2021

ASTRONOMY - Road to the Galactic Center

 2021 October 25

The picture shows the a composite image of Monument Valley, Utah, USA 
in the foreground, and the plane of the Milky Way Galaxy including 
the Galactic Center in the background. 
Please see the explanation for more detailed information.

Road to the Galactic Center
Image Credit & Copyright: Michael Abramyan

Explanation: Does the road to our galaxy's center go through Monument Valley? It doesn't have to, but if your road does -- take a picture. In this case, the road is US Route 163 and iconic buttes on the Navajo National Reservation populate the horizon. The band of Milky Way Galaxy stretches down from the sky and appears to be a continuation of the road on Earth. Filaments of dust darken the Milky Way, in contrast to billions of bright stars and several colorful glowing gas clouds including the Lagoon and Trifid nebulas. The featured picture is a composite of images taken with the same camera and from the same location -- Forest Gump Point in UtahUSA. The foreground was taken just after sunset in early September during the blue hour, while the background is a mosaic of four exposures captured a few hours later.

05/11/2021

ASTRONOMY - Lucy Launches to Eight Asteroids

 2021 October 20

The picture shows the NASA's Lucy mission
launching from Cape Canaveral, Florida. 
Please see the explanation for more detailed information.

Lucy Launches to Eight Asteroids
Image Credit & Copyright: John Kraus

Explanation: Why would this mission go out as far as Jupiter -- but then not visit Jupiter? Lucy's plan is to follow different leads about the origin of our Solar System than can be found at Jupiter -- where Juno now orbits. Jupiter is such a massive planet that its gravity captures numerous asteroids that orbit the Sun ahead of it -- and behind. These trojan asteroids formed all over our Solar System and some may have been trapped there for billions of years. Flying by these trojan asteroids enables studying them as fossils that likely hold unique clues about our early Solar System. Lucy, named after a famous fossil skeleton which was named after a famous song, is scheduled to visit eight asteroids from 2025 to 2033. Pictured, Lucy's launch was captured with reflection last week aboard a powerful Atlas V rocket from Cape CanaveralFloridaUSA.

04/11/2021

ASTRONOMY - Earthshine Moon over Sicily

2021 October 18
The picture shows the sky over Sicily, Italy earlier this month
featuring a crescent moon with Earthshine, Venus, and Antares.
Please see the explanation for more detailed information.

Earthshine Moon over Sicily
Image Credit & Copyright: Dario Giannobile

Explanation: Why can we see the entire face of this Moon? When the Moon is in a crescent phase, only part of it appears directly illuminated by the Sun. The answer is earthshine, also known as earthlight and the da Vinci glow. The reason is that the rest of the Earth-facing Moon is slightly illuminated by sunlight first reflected from the Earth. Since the Earth appears near full phase from the Moon -- when the Moon appears as a slight crescent from the Earth -- earthshine is then near its brightest. Featured here in combined, consecutively-taken, HDR images taken earlier this month, a rising earthshine Moon was captured passing slowly near the planet Venus, the brightest spot near the image center. Just above Venus is the star Dschubba (catalogued as Delta Scorpii), while the red star on the far left is Antares. The celestial show is visible through scenic cloud decks. In the foreground are the lights from Palazzolo Acreide, a city with ancient historical roots in SicilyItaly

MUSIC - Richard Wagner - The ride of Walkyries

"The ride of Walkyries"

SANTé/MEDECINE - A la découverte de l'oreille - La trompe d'Eustache

La trompe d'Eustache (en rouge) est un conduit oblique qui relie l' oreille moyenne à la partie supérieure de la gorge : la muqueus...