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05/08/2021
SANTé/MéDECINE - Fracture de la verge… dans le sens vertical !
SANTé/MEDECINE - Le remède très simple pour soulager une piqure de moustique
ASTRONOMY - The Andromeda Galaxy in Ultraviolet
2021 July 18
Image Credit: NASA, JPL-Caltech, GALEX
Explanation: What does the Andromeda galaxy look like in ultraviolet light? Young blue stars circling the galactic center dominate. A mere 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go. Spanning about 230,000 light-years, it took 11 different image fields from NASA's Galaxy Evolution Explorer (GALEX) satellite telescope to produce this gorgeous portrait of the spiral galaxy in ultraviolet light in 2003. While its spiral arms stand out in visible light images, Andromeda's arms look more like rings in ultraviolet. The rings are sites of intense star formation and have been interpreted as evidence that Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago. The Andromeda galaxy and our own comparable Milky Way galaxy are the most massive members of the Local Group of galaxies and are projected to collide in several billion years -- perhaps around the time that our Sun's atmosphere will expand to engulf the Earth.
04/08/2021
ASTRONOMY - EHT Resolves Central Jet from Black Hole in Cen A
2021 August 4
Image Credit: Radboud University; CSIRO/ATNF/I.Feain et al., R.Morganti et al., N.Junkes et al.; ESO/WFI; MPIfR/ESO/APEX/A. Weiss et al.; NASA/CXC/CfA/R. Kraft et al.; TANAMI/C. Mueller et al.; EHT/M. Janssen et al.
Explanation: How do supermassive black holes create powerful jets? To help find out, the Event Horizon Telescope (EHT) imaged the center of the nearby active galaxy Centaurus A. The cascade of featured inset images shows Cen A from it largest, taking up more sky than many moons, to its now finest, taking up only as much sky as an golf ball on the moon. The new image shows what may look like two jets -- but is actually two sides of a single jet. This newly discovered jet-edge brightening does not solve the jet-creation mystery, but does imply that the particle outflow is confined by a strong pressure -- possibly involving a magnetic field. The EHT is a coordination of radio telescopes from around the Earth -- from the Caltech Submillimeter Observatory in Hawaii USA, to ALMA in Chile, to NOEMA in France, and more. The EHT will continue to observe massive, nearby black holes and their energetic surroundings.
03/08/2021
ASTRONOMIE - La nuit des étoiles
Quelles sont les dates pour 2021 ?
I-PHONE ASTUCES - Plein de photos d'un seul coup
Prendre une rafale de photos d’un coup Vous voulez prendre plein de photos d'un seul coup ? Il suffit de rester appuyé sur le bouton pour enclencher le mode rafale automatiquement.
ASTRONOMY - A Perseid Fireball and the Milky Way
2021 August 3
Image Credit & Copyright: Dandan Huang
Explanation: It was bright and green and flashed as it moved quickly along the Milky Way. It left a trail that took 30 minutes to dissipate. Given the day, August 12, and the direction, away from Perseus, it was likely a small bit from the nucleus of Comet Swift-Tuttle plowing through the Earth's atmosphere -- and therefore part of the annual Perseids meteor shower. The astrophotographer captured the fireball as it shot across the sky in 2018 above a valley in Yichang, Hubei, China. The meteor's streak, also caught on video, ended near the direction of Mars on the lower left. Next week, the 2021 Perseids meteor shower will peak again. This year the Moon will set shortly after the Sun, leaving a night sky ideal for seeing lots of Perseids from dark and clear locations across planet Earth.
02/08/2021
PRATIQUE/POURQUOI - Pourquoi un glaçon flotte t-il sur l'eau ?
ASTRONOMY - The Hubble Ultra Deep Field in Light and Sound
Image Credit: NASA, ESA, Hubble; Sonification: G. Salvesen (UCSB); Data: M. Rafelski et al.
Explanation: Have you heard about the Hubble Ultra-Deep Field? Either way, you've likely not heard about it like this -- please run your cursor over the featured image and listen! The Hubble Ultra-Deep Field (HUDF) was created in 2003-2004 with the Hubble Space Telescope staring for a long time toward near-empty space so that distant, faint galaxies would become visible. One of the most famous images in astronomy, the HUDF is featured here in a vibrant way -- with sonified distances. Pointing to a galaxy will play a note that indicates its approximate redshift. Because redshifts shift light toward the red end of the spectrum of light, they are depicted here by a shift of tone toward the low end of the spectrum of sound. The further the galaxy, the greater its cosmological redshift (even if it appears blue), and the lower the tone that will be played. The average galaxy in the HUDF is about 10.6 billion light years away and sounds like an F#. What's the most distant galaxy you can find?
31/07/2021
AERONAUTIQUE - Histoire de l'aviation - (2)
Le début du 21ème siècle : le transport aérien c'est tellement développé que certaines zones sont saturées. Sur le plan militaire, l'avion n'est qu'un des composants des systèmes de l'armée et le rôle des pilotes se réduit au profit des systèmes automatiques. 1. Les premiers planeurs. Le premier homme à avoir plané en dirigeant son avion s'appelle Otto Lilienthal, il a effectué plus de 2000 vols avec sa machine en sautant d'une colline. Les premiers vols fait à partir d'un avion muni d'un gouvernail qui permettait de contrôler la trajectoire de celui-ci ont été réalisés par les frères Wright.
ASTRONOMY - Christmas Tree Aurora
2024 December 23 Christmas Tree Aurora Image Credit & Copyright: Jingyi Zhang Explanation: It was December and the sky lit up like a ...
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2021 May 11 Lightning and Orion Beyond Uluru Image Credit & Copyright: Park Liu Explanation: What's happening behind Uluru? A Un...
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Extraordinary Solar Halos Image Credit & Copyright : Magnus Edback Explanation: Welcome to the December Solstice, the first...