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14/02/2025
SANTé/MEDECINE - Le cerveau - Les cellules de Purkinje - des neurones du cervelet
ASTRONOMY - A Cosmic Rose: NGC 2237 in Monoceros
2025 February 14
Image Credit & Copyright: Harry Karamitsos
Explanation: The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is probably the most famous. At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young, O-type stars. Stars in the energetic cluster, cataloged as NGC 2244, are only a few million years young, while the central cavity in the Rosette Nebula, is about 50 light-years in diameter. The nebula can be seen with a small telescope toward the constellation of Monoceros, the Unicorn. This natural appearing telescopic portrait of the Rosette Nebula was made using broadband color filters, but sometimes roses aren't red.
13/02/2025
ARCHEOLOGIE - Le trésor de Toutânkhamon - La Maison d’éternité du pharaon
ASTRONOMY - Reflections on VdB 31
2025 February 13
Image Credit & Copyright: Roberto Marinoni
Explanation: Riding high in the constellation of Auriga, beautiful, blue VdB 31 is the 31st object in Sidney van den Bergh's 1966 catalog of reflection nebulae. It shares this well-composed celestial still life with dark, obscuring clouds B26, B27, and B28, recorded in Edward E. Barnard's 1919 catalog of dark markings in the sky. All are these nebulae are interstellar dust clouds. Barnard's dark nebulae block the light from background stars. For VdB 31 the dust preferentially reflects bluish starlight from embedded, hot, variable star AB Aurigae. Exploring the environs of AB Aurigae with the Hubble Space Telescope has revealed the several million year young star is itself surrounded by a flattened dusty disk with evidence for the ongoing formation of a planetary system. AB Aurigae is about 470 light-years away. At that distance this cosmic canvas would span about eight light-years.
12/02/2025
ASTRONOMIE - Observer Mars - La mythique planète rouge
SANTé/MEDECINE - Le cerveau - Reconstitution tridimensionnelle d'une boîte crânienne
ASTRONOMY - Asteroid Bennu Holds the Building Blocks of Life
2025 February 12
Video Credit: Data: NASA, SVS, U. Arizona, CSA, York U., MDA; Visualizer: Kel Elkins (lead, SVS); Text:
Explanation: What can a space rock tell us about life on Earth? NASA's OSIRIS-REx spacecraft made a careful approach to the near-Earth asteroid 101955 Bennu in October of 2020 to collect surface samples. In September 2023, the robotic spaceship returned these samples to Earth. A recent analysis has shown, surprisingly, that the samples contained 14 out of the 20 known amino acids that are the essential building blocks of life. The presence of the amino acids re-introduces a big question: Could life have originated in space? However, the protein building blocks themselves held another surprise -- they contained an even mixture of left-handed and right-handed amino acids -- in contrast to our Earth which only has left-handed ones. This raises another big question: Why does life on Earth have only left-handed amino acids? Research on this is sure to continue.
11/02/2025
ASTRONOMY - The Spider and the Fly
2025 February 11
Image Credit & Copyright: Dave Boddington
Explanation: Will the spider ever catch the fly? Not if both are large emission nebulas toward the constellation of the Charioteer (Auriga). The spider-shaped gas cloud in the image center is actually an emission nebula labelled IC 417, while the smaller fly-shaped cloud on the left is dubbed NGC 1931 and is both an emission nebula and a reflection nebula. About 10,000 light-years distant, both nebulas harbor young star clusters. For scale, the more compact NGC 1931 (Fly) is about 10 light-years across. The featured deep image, captured over 20 hours during late January in Berkshire UK, also shows more diffuse and red-glowing interstellar gas and dust.
10/02/2025
ARCHEOLOGIE - Le trésor de Toutânkhamon - La Maison d’éternité du pharaon
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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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2024 July 5 Mount Etna Milky Way Image Credit & Copyright : Gianni Tumino Explanation: A glow from the summit of Mount Etna , famous ...