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21/08/2025
SANTé/MEDECINE - GUERISON DU CANCER - Un espoir immense - La troisième voie -4/7-
20/08/2025
SANTé/MEDECINE - LA GUERISON DU CANCER : Un espoir immense - La troisième voie -3/7-
ASTRONOMY - Perseid Meteors from Durdle Door
2025 August 20
Image Credit & Copyright: Josh Dury
Explanation: What are those curved arcs in the sky? Meteors -- specifically, meteors from this year's Perseid meteor shower. Over the past few weeks, after the sky darkened, many images of Perseid meteors were captured separately and merged into a single frame, taken earlier. Although the meteors all traveled on straight paths, these paths appear slightly curved by the wide-angle lens of the capturing camera. The meteor streaks can all be traced back to a single point on the sky called the radiant, here just off the top of the frame in the constellation of Perseus. The same camera took a deep image of the background sky that brought up the central band of our Milky Way galaxy running nearly vertically through the featured image's center. The limestone arch in the foreground in Dorset, England is known as Durdle Door, a name thought to survive from a thousand years ago.
19/08/2025
ASTRONOMY - Giant Galaxies in Pavo
Image Credit & Copyright: Adam Block
Explanation: Over 500,000 light years across, NGC 6872 (bottom left) is a truly enormous barred spiral galaxy. At least 5 times the size of our own large Milky Way, NGC 6872 is the largest known spiral galaxy. About 200 million light-years distant toward the southern constellation Pavo, the Peacock, the appearance of this giant galaxy's stretched out spiral arms suggest the wings of a giant bird. So its popular moniker is the Condor galaxy. Lined with massive young, bluish star clusters and star-forming regions, the extended and distorted spiral arms are due to NGC 6872's past gravitational interactions with the nearby smaller galaxy IC 4970, visible here below the giant spiral galaxy's core. Other members of the southern Pavo galaxy group are scattered through this magnificent galaxy group portrait, with the dominant giant elliptical galaxy, NGC 6876, above and right of the soaring Condor galaxy.
18/08/2025
SANTé/MEDECINE - LA GUERISON DU CANCER : Un espoir immense - La troisième voie -2/7-
SANTé/MEDECINE - LA GUERISON DU CANCER : Un espoir immense - La troisième voie -1/7-
17/08/2025
SANTé/MEDECINE - Cancer rare : ces symptômes passent souvent inaperçus... (3/3)
ASTRONOMY - Asperitas Clouds Over New Zealand
2025 August 17
Image Credit & Copyright: Witta Priester
Explanation: What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Formally recognized as a distinct cloud type only last year, asperitas clouds can be stunning in appearance, unusual in occurrence, and are relatively unstudied. Whereas most low cloud decks are flat bottomed, asperitas clouds appear to have significant vertical structure underneath. Speculation therefore holds that asperitas clouds might be related to lenticular clouds that form near mountains, or mammatus clouds associated with thunderstorms, or perhaps a foehn -- a type of dry downward wind that flows off mountains. Clouds from such a wind called the Canterbury arch stream toward the east coast of New Zealand's South Island. The featured image, taken above Hanmer Springs in Canterbury, New Zealand in 2005, shows great detail partly because sunlight illuminates the undulating clouds from the side.
16/08/2025
ASTRONOMY - A Cool GIF of a 2025 Perseid
2025 August 16
Image Credit & Copyright: Renaud & Olivier Coppe
Explanation: The camera battery died about 2am local time on August 12, while shooting in the bright moonlit skies from a garden in Chastre, Brabant Wallon, Belgium, planet Earth. But not before it captured the frames used to compose this cool animated gif of a brilliant Perseid meteor and a lingering visible trail known as a persistent train. The Perseid meteor, a fast moving speck of dust from the tail of large periodic Comet Swift-Tuttle, was heated to incandescence by ram pressure and vaporized as it flashed through the upper atmosphere at 60 kilometers per second. Compared to the brief flash of the meteor, its wraith-like trail really is persistent. A characteristic of bright meteors, a smoke-like persistent train can often be followed for many minutes wafting in the winds at altitudes of 60 to 90 kilometers.
15/08/2025
ASTRONOMY - Moonlight, Planets, and Perseids
2025 August 15
Image Credit & Copyright: Jeff Dai (TWAN)
Explanation: In the predawn sky on August 13, two planets were close. And despite the glare of a waning gibbous Moon, bright Jupiter and even brighter Venus were hard to miss. Their brilliant close conjunction is posing above the eastern horizon in this early morning skyscape. The scene was captured in a single exposure from a site near Gansu, China, with light from both planets reflected in the still waters of a local pond. Also seen against the moonlight were flashes from the annual Perseid Meteor Shower, known for its bright, fast meteors. Near the much anticipated peak of activity, the shower meteors briefly combined with the two planets for a celestial spectacle even in moonlit skies.
14/08/2025
ASTRONOMY - Zodiacal Road
Image Credit & Copyright: Ruslan Merzlyakov (astrorms)
Explanation: What's that strange light down the road? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently just after sunset -- or just before sunrise -- and is called zodiacal light. Although the origin of this dust is still being researched, a leading hypothesis holds that zodiacal dust originates mostly from faint Jupiter-family comets and slowly spirals into the Sun. Recent analysis of dust emitted by Comet 67P, visited by ESA's robotic Rosetta spacecraft, bolsters this hypothesis. Pictured when climbing a road up to Teide National Park in the Canary Islands of Spain, a bright triangle of zodiacal light appeared in the distance soon after sunset. Captured on June 21, 2019, the scene includes bright Regulus, the alpha star of the constellation Leo, standing above center toward the left. The Beehive Star Cluster (M44) can be spotted below center, closer to the horizon and also immersed in the zodiacal glow.
12/08/2025
ASTRONOMY - Perseids from Perseus
2025 August 12
Image Credit & Copyright: Marcin Rosadziński
Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tonight is known as the Perseids -- the meteors all appear to come from a radiant toward Perseus. In terms of parent body, though, the sand-sized debris that makes up the Perseids meteors come from Comet Swift-Tuttle. The comet follows a well-defined orbit around our Sun, and the part of the orbit that approaches Earth is superposed in front of Perseus. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Perseus. Featured here, a composite image taken over six nights and containing over 100 meteors from 2024 August Perseids meteor shower shows many bright meteors that streaked over the Bieszczady Mountains in Poland. This year's Perseids, usually one of the best meteor showers of the year, will compete with a bright moon that will rise, for many locations, soon after sunset.
11/08/2025
SANTé/MEDECINE - Cancer rare : ces symptômes passent souvent inaperçus... (2/3)
ASTRONOMY - Closest Ever Images Near the Sun
2025 August 11
Closest Ever Images Near the Sun
Explanation: Everybody sees the Sun. Nobody's been there. Starting in 2018, though, NASA launched the robotic Parker Solar Probe (PSP) to investigate regions near to the Sun for the first time. The featured time-lapse video shows the view looking sideways from behind PSP's Sun shield in December during the closest approach of any human-made spacecraft to the Sun, looping down to only about five solar diameters above the Sun's hot surface. The PSP's Wide Field Imager for Solar Probe (WISPR) cameras took these images over seven hours, but they are digitally compressed here into about 5 seconds. The solar corona, including colliding coronal mass ejections (CMEs), is visible here in unprecedented detail, with stars passing far in the background. The Sun is not only Earth's dominant energy source, but its variable solar wind also compresses Earth's atmosphere, triggers auroras, affects power grids, and can even damage orbiting communication satellites.
09/08/2025
ASTRONOMY - Interstellar Interloper 3I/ATLAS from Hubble
Image Credit: NASA, ESA, David Jewitt (UCLA) et al. - Processing; Joseph DePasquale (STScI)
Explanation: Discovered on July 1 with the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile, 3I/ATLAS is so designated as the third known interstellar object to pass through our Solar System. It follows 1I/ʻOumuamua in 2017 and the comet 2I/Borisov in 2019. Also known as C/2025 N1, 3I/ATLAS is a comet. A teardrop-shaped cloud of dust, ejected from its icy nucleus warmed by increasing sunlight, is seen in this sharp image from the Hubble Space Telescope captured on July 21. Background stars are streaked in the exposure as Hubble tracked the fastest comet ever recorded on its journey toward the inner solar system. An analysis of the Hubble image indicates the solid nucleus, hidden from direct view, is likely less that 5.6 kilometers in diameter. This comet's interstellar origin is clear from its orbit, determined to be an eccentric, highly hyperbolic orbit that does not loop back around the Sun and will return 3I/ATLAS to interstellar space. Not a threat to planet Earth, the inbound interstellar interloper is now within the Jupiter's orbital distance of the Sun, while its closest approach to the Sun will bring it just inside the orbital distance of Mars.
08/08/2025
SANTé/MEDECINE - Les effets de la marche sur le corps - Fin
07/08/2025
ASTRONOMY - The Double Cluster in Perseus
2025 August 7
Image Credit & Copyright: Ron Brecher
Explanation: This stunning starfield spans about three full moons (1.5 degrees) across the heroic northern constellation of Perseus. It holds the famous pair of open star clusters, h and Chi Persei. Also cataloged as NGC 869 (right) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters are both 13 million years young based on the ages of their individual stars, evidence that both clusters were likely a product of the same star-forming region. Always a rewarding sight in binoculars or small telescopes, the Double Cluster is even visible to the unaided eye from dark locations.
06/08/2025
ASTRONOMIE - Un superbe duo Vénus-Jupiter à l’aube
ASTRONOMY - Meteor before Galaxy
2025 August 6
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 next week, although this year the meteors will have to outshine a sky brightened by a nearly full moon.
SANTé/MEDECINE - Les effets de la marche sur le corps -3/5 -
05/08/2025
SANTé/MEDECINE - Les effets de la marche sur le corps -2/5 -
ASTRONOMY - NGC 6072: A Complex Planetary Nebula from Webb
2025 August 5
Image Credit: NASA, ESA, CSA, STScI, JWST
Explanation: Why is this nebula so complex? The Webb Space Telescope has imaged a nebula in great detail that is thought to have emerged from a Sun-like star. NGC 6072 has been resolved into one of the more unusual and complex examples of planetary nebula. The featured image is in infrared light with the red color highlighting cool hydrogen gas. Study of previous images of NGC 6072 indicated several likely outflows and two disks inside the jumbled gas, while the new Webb image resolves new features likely including one disk's edge protruding on the central left. A leading origin hypothesis holds that the nebula's complexity is caused or enhanced by multiple outbursts from a star in a multi-star system near the center.
04/08/2025
SANTé/MEDECINE - Cancer rare : ces symptômes passent souvent inaperçus... (1/3)
ASTRONOMY - Blue Arcs Toward Andromeda
2025 August 4
Image Credit & Copyright: Ogle et al.
Explanation: What are these gigantic blue arcs near the Andromeda Galaxy (M31)? Discovered in 2022 by amateur astronomers, the faint arcs -- dubbed SDSO 1 -- span nearly the same angular size as M31 itself. At first, their origin was a mystery: are they actually near the Andromeda Galaxy, or alternatively near to our Sun? Now, over 550 hours of combined exposure and a collaboration between amateur and professional astronomers has revealed strong evidence for their true nature: SDSO 1 is not intergalactic, but a new class of planetary nebula within our galaxy. Dubbed a Ghost Planetary Nebula (GPN), SDSO 1 is the first recognized member of a new subclass of faded planetary nebulas, along with seven others also recently identified. Shown in blue are extremely faint oxygen emission from the shock waves, while the surrounding red is a hydrogen-emitting trail that indicates the GPN's age.
SANTé/MEDECINE - Les effets de la marche sur le corps -1/5 -
03/08/2025
NUCLEAIRE - EPR : Danger à Flamanville
ASTRONOMY - Milky Way and Exploding Meteor
2025 August 3
Image Credit & Copyright: Andre van der Hoeven
Explanation: In about a week the Perseid Meteor Shower will reach its maximum. Grains of icy rock will streak across the sky as they evaporate during entry into Earth's atmosphere. These grains were shed from Comet Swift-Tuttle. The Perseids result from the annual crossing of the Earth through Comet Swift-Tuttle's orbit, and are typically the most active meteor shower of the year. Although it is hard to predict the level of activity in any meteor shower, in a clear dark sky an observer might see a meteor a minute. This year's Perseids peak just a few days after full moon, and so some faint meteors will be lost to the lunar skyglow. Meteor showers in general are best seen from a relaxing position, away from lights. Featured here is a meteor caught exploding during the 2015 Perseids above Austria next to the central band of our Milky Way Galaxy.
02/08/2025
ASTRONOMY - Fireflies, Meteors, and Milky Way
2025 August 2
Image Credit & Copyright: Daniel Korona
Explanation: Taken on July 29 and July 30, a registered and stacked series of exposures creates this dreamlike view of a northern summer night. Multiple firefly flashes streak across the foreground as the luminous Milky Way arcs above the horizon in the Sierra de Órganos national park of central Mexico, The collection of bright streaks aligned across the sky toward the upper left in the timelapse image are Delta Aquariid meteors. Currently active, the annual Delta Aquarid meteor shower shares August nights though, overlapping with the better-known Perseid meteor shower. This year that makes post-midnight, mostly moonless skies in early August very popular with late night skygazers. How can you tell a Delta Aquariid from a Perseid meteor? The streaks of Perseid meteors can be traced back to an apparent radiant in the constellation Perseus. Delta Aquariids appear to emerge from the more southerly constellation Aquarius, beyond the top left of this frame. Of course, the bioluminescent flashes of fireflies are common too on these northern summer nights. But how can you tell a firefly from a meteor? Just try to catch one.
01/08/2025
SANTé/MEDECINE - Marcher c'est réduire les risques de cancer (4/4)
ASTRONOMY - Small Dark Nebula
Image Credit & Copyright: Peter Bresseler
Explanation: A small, dark, nebula looks isolated near the center of this telescopic close-up. The wedge-shaped cosmic cloudlet lies within a relatively crowded region of space though. About 7,000 light-years distant and filled with glowing gas and an embedded cluster of young stars, the region is known as M16 or the Eagle Nebula. Hubble's iconic images of the Eagle Nebula include the famous star-forming Pillars of Creation, towering structures of interstellar gas and dust 4 to 5 light-years long. But this small dark nebula, known to some as a Bok globule, is a fraction of a light-year across. The Bok globule stands out in silhouette against the expansive background of M16's diffuse glow. Found scattered within emission nebulae and star clusters, Bok globules are small interstellar clouds of cold molecular gas and obscuring dust that also form stars within their dense, collapsing cores.
SANTé/MEDECINE - GUERISON DU CANCER - Un espoir immense - La troisième voie -4/7-
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2025 January 14 North Star: Polaris and Surrounding Dust Image Credit & Copyright: Davide Coverta Explanation: Why is Polaris called ...