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15/07/2025
LA TERRE VUE DU CIEL - La cordillère des Andes - chaîne de montagnes
SANTé/MEDECINE - Détecter le cancer dans les analyses de sang - (5) - Les témoignages qui bouleversent
ASTRONOMY - Collapse in Hebes Chasma on Mars
025 July 15
Image Credit & License: ESA/DLR/FU Berlin (G. Neukum)
Explanation: What's happened in Hebes Chasma on Mars? Hebes Chasma is a depression just north of the enormous Valles Marineris canyon. Since the depression is unconnected to other surface features, it is unclear where the internal material went. Inside Hebes Chasma is Hebes Mensa, a 5 kilometer high mesa that appears to have undergone an unusual partial collapse -- a collapse that might be providing clues. The featured image, taken by ESA's robotic Mars Express spacecraft currently orbiting Mars, shows great details of the chasm and the unusual horseshoe shaped indentation in the central mesa. Material from the mesa appears to have flowed onto the floor of the chasm, while a possible dark layer appears to have pooled like ink on a downslope landing. One hypothesis holds that salty rock composes some lower layers in Hebes Chasma, with the salt dissolving in melted ice flows that drained through holes into an underground aquifer.
14/07/2025
ASTRONOMY - NGC 2685: The Helix Galaxy
2025 July 14
Image Credit & Copyright: Stefan Thrun
Explanation: What is going on with this galaxy? NGC 2685 is a confirmed polar ring galaxy - a rare type of galaxy with stars, gas and dust orbiting in rings perpendicular to the plane of a flat galactic disk. The bizarre configuration could be caused by the chance capture of material from another galaxy by a disk galaxy, with the captured debris strung out in a rotating ring. Still, observed properties of NGC 2685 suggest that the rotating helix structure is remarkably old and stable. In this sharp view of the peculiar system also known as Arp 336 or the Helix galaxy, the strange, perpendicular rings are easy to trace as they pass in front of the galactic disk, along with other disturbed outer structures. NGC 2685 is about 50,000 light-years across and 40 million light-years away in the constellation of the Great Bear (Ursa Major).
13/07/2025
LA TERRE VUE DU CIEL - Brasilia - Capitale du Brésil
SANTé/MEDECINE - Comment soulager une piqûre de moustique en 1 minute
ASTRONOMY - Planetary Nebula Mz3: The Ant Nebula
2025 July 13
Image Credit: NASA, ESA, R. Sahai (JPL) et al., Hubble Heritage Team
Explanation: Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round? Clues might include the high 1000-kilometer per second speed of the expelled gas, the light-year long length of the structure, and the magnetism of the star featured here at the nebula's center. One possible answer is that Mz3 is hiding a second, dimmer star that orbits close in to the bright star. A competing hypothesis holds that the central star's own spin and magnetic field are channeling the gas. Since the central star appears to be so similar to our own Sun, astronomers hope that increased understanding of the history of this giant space ant can provide useful insight into the likely future of our own Sun and Earth.
12/07/2025
ASTRONOMY - Clouds and the Golden Moon
Image Credit & Copyright: Alexsandro Mota
Explanation: As the Sun set, a bright Full Moon rose on July 10. Its golden light illuminates clouds drifting through southern hemisphere skies in this well-composed telephoto image from Conceição do Coité, Bahia, Brazil. The brightest lunar phase is captured here with both a short and long exposure. The two exposures were combined to reveal details of the lunar surface in bright moonlight and a subtle iridescence along the dramatically backlit cloudscape. Of course, July's Full Moon is a winter moon in the southern hemisphere. But in the north it's known to some as the Thunder Moon, likely a nod to the sounds of this northern summer month's typically stormy weather.
11/07/2025
SANTé/MEDECINE - Détecter le cancer dans les analyses de sang - (4) - Des bénéfices extraordinaires pour la santé publique
LA TERRE VUE DU CIEL - Glaciers de Patagonie
ASTRONOMY - Perseids from Perseus
2025 August 12 Perseids from Perseus Image Credit & Copyright: Marcin Rosadziński Explanation: Where are all of these meteors coming ...

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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 January 14 North Star: Polaris and Surrounding Dust Image Credit & Copyright: Davide Coverta Explanation: Why is Polaris called ...