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08/06/2024
NUCLEAIRE - Comment survivre à une explosion nucléaire ? - Comment bien se préparer ?
ASTRONOMY - Pandora's Cluster of Galaxies
2024 June 8
Image Credit: NASA, ESA, CSA, Ivo Labbe (Swinburne), Rachel Bezanson (University of Pittsburgh), Processing: Alyssa Pagan (STScI)
Explanation: This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 recorded by the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters. It lies some 3.5 billion light-years away, toward the constellation Sculptor. Dominated by dark matter, the mega-cluster warps and distorts the fabric of spacetime, gravitationally lensing even more distant objects. Redder than the Pandora cluster galaxies many of the lensed sources are very distant galaxies in the early Universe, their lensed images stretched and distorted into arcs. Of course distinctive diffraction spikes mark foreground Milky Way stars. At the Pandora Cluster's estimated distance this cosmic box spans about 6 million light-years. But don't panic. You can explore the tantalizing region in a 2 minute video tour.
07/06/2024
NUCLEAIRE - Comment survivre à une explosion nucléaire - Restez connecté
ASTRONOMY - SH2-308: The Dolphin Head Nebula
2024 June 7
Image Credit & Copyright: Prabhu Kutti
Explanation: Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,000 light-years away toward the well-trained constellation Canis Major and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured by narrowband filters in the deep image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. Presenting a mostly harmless outline, SH2-308 is also known as The Dolphin-head Nebula.
06/06/2024
NUCLEAIRE - Comment survivre à une explosion nucléaire - Nettoyez !
ASTRONOMY - NGC 4565: Galaxy on Edge
2024 June 6
Image Credit & Copyright: Lóránd Fényes
05/06/2024
SANTé/MEDECINE - Virus et bactéries mortels - Le Virus A H5N1, à l'origine de la grippe qui fait trembler le monde
NUCLEAIRE - Comment survivre à une explosion nucléaire ? Mettez des priorités en place
ASTRONOMY - Shadow of a Martian Robot
2024 June 5
Image Credit: NASA, JPL-Caltech, MSSS, ASU, NeV-T, Perseverance Rover;
Processing & Copyright: Neville Thompson, Gigapan Zoom
Explanation: What if you saw your shadow on Mars and it wasn't human? Then you might be the Perseverance rover exploring Mars. Perseverance has been examining the Red Planet since 2021, finding evidence of its complex history of volcanism and ancient flowing water, and sending breathtaking images across the inner Solar System. Pictured here in February of 2024, Perseverance looks opposite the Sun and across Neretva Vallis in Jezero Crater, with a local hill visible at the top of the frame. The distinctively non-human shadow of the car-sized rover is visible below center, superposed on scattered rocks. Perseverance, now working without its flying companion Ingenuity, continues to search Mars for signs of ancient life.
04/06/2024
SANTé/MEDECINE - Virus et bactéries mortels - Mycobacterium tuberculosis, l'agent mortel de la tuberculose
LA TERRE VUE DU CIEL - Houston ; siège du Centre spatial Johnson de la Nasa
Houston n'est pas seulement la ville qui abrite le siège des vols habités de la Nasa . Elle est également connue pour être la capitale ...
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2022 September 26 All the Water on Planet Earth Illustration Credit: Jack Cook, Adam Nieman, Woods Hole Oceanographic Institution ; Data ...
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2025 February 17 SpaceX Rocket Launch Plume over California Image Credit & Copyright: Martin LaMontagne Explanation: What's happe...