9 - SCIENCE - JoanMira
La Science sous toutes ses formes/Science in all its forms
Nombre total de pages vues
17/02/2026
LINGUISTIQUE - Les origines de la langue basque - (1/2)
ASTRONOMY - Tails of Comet Wierzchoś
2026 February 17
Image Credit & Copyright: José J. Chambó;
Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
Explanation: Some comets are regular guests of our solar neighborhood; others come by only once, never to return. We won’t have another chance to see Comet C/2024 E1 (Wierzchoś), which is currently making its way through the inner Solar System. The hyperbolic orbit of this comet indicates that it will likely become an interstellar traveler. Comet Wierzchoś is today near its closest approach to the Earth, passing roughly the same distance from the Earth as is the Sun. The featured 30-minute exposure was taken last week in Chile and shows a 5-degree long ion tail as well as three shorter dust tails. The green hue of the coma comes from the breakdown of dicarbon molecules by sunlight, but that process does not last long enough to also tinge the tails. On the far right lies a spiral galaxy far in the distance: NGC 300.
16/02/2026
ASTRONOMY - Unexplained Shocks Around a White Dwarf Star
2026 February 16
Image Credit: ESO, K. Iłkiewicz & S. Scaringi et al.;
Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
Explanation: How is RXJ0528+2838 creating such shock waves? A recently discovered white dwarf star, the farther left of the two largest white spots, RXJ0528+2838, was found 730 light-years away from Earth. Most stars, when done fusing nuclei in their cores for energy, become red giant stars, the cores of which live on as faint dense white dwarfs that slowly cool down for the rest of time. White dwarfs are so dense that the only thing that stops them from collapsing further is quantum mechanics. In about 5 billion years, our Sun will become a white dwarf, too. The featured image, obtained with the European Southern Observatory’s Very Large Telescope, shows unexplained bow shocks around RXJ0528+2838, similar to the bow wave of water around a fast-moving ship. Astronomers don’t yet know what is powering these shocks, which have existed for at least 1,000 years. The red, green and blue colors represent trace amounts of glowing hydrogen, nitrogen and oxygen gas.
MICROPHOTOGRAPHIE - Écailles de serpent ou dendrites métalliques ?
15/02/2026
ASTRONOMY - To Fly Free in Space
2026 February 15
Image Credit: NASA, STS-41B
Explanation: What would it be like to fly free in space? About 100 meters from the cargo bay of a space shuttle, Bruce McCandless II was living the dream -- floating farther out than anyone had ever been before. Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured, was floating free in space. During Space Shuttle mission 41-B in 1984, McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an "untethered space walk". The MMU worked by shooting jets of nitrogen and was used to help deploy and retrieve satellites. With a mass over 140 kilograms, an MMU is heavy on Earth, but, like everything, is weightless when drifting in orbit. The MMU was later replaced with the SAFER backpack propulsion unit.
13/02/2026
ASTRONOMY - Red Spider Planetary Nebula from Webb
2026 February 3
Image Credit: ESA/Webb, NASA & CSA, J. H. Kastner (RIT)
Explanation: Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds flowing out from the central stars, have been measured in excess of 1,000 kilometers per second. These winds expand the nebula, flow along the nebula's walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the featured false-color infrared picture by the James Webb Space Telescope. The Red Spider Nebula lies toward the constellation of the Archer (Sagittarius). Its distance is not well known but has been estimated by some to be about 4,000 light-years.
SANTé/MEDECINE - Tout savoir sur le coeur - 11 - Opérations du cœur
12/02/2026
ASTRONOMY -The Bay of Rainbows
2026 February 12
Image Credit & Copyright: Olaf Filzinger
Explanation: Dark, smooth regions that cover the Moon's familiar face are called by Latin names for oceans and seas. That naming convention is historical, though it may seem a little ironic to denizens of the space age who recognize the Moon as a mostly dry and airless world, and the smooth, dark areas as lava-flooded impact basins. For example, this telescopic lunar vista, looks over the expanse of the northwestern Mare Imbrium, or Sea of Rains and into the Sinus Iridum, the Bay of Rainbows. Ringed by the Jura Mountains (montes), the bay is about 250 kilometers across. Seen after local sunrise, the mountains form part of the Sinus Iridum impact crater wall. Their rugged sunlit arc is bounded at the top by Cape (promontorium) Laplace reaching nearly 3,000 meters above the bay's surface. At the bottom of the arc is Cape Heraclides, depicted by Giovanni Cassini in his 1679 telescope-based drawings mapping the moon, as a moon maiden seen in profile with long, flowing hair.
11/02/2026
SANTé/MEDECINE - Tout savoir sur le coeur humain - 10 - Infarctus dans le ventricule gauche
ASTRONOMY - A Year of Sunspots
2026 February 11
Image Credit: NASA, SDO; Processing & Copyright: Şenol Şanli & Uğur İkizler; Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
Explanation: How many sunspots can you see? The central image shows the many sunspots that occurred in 2025, month by month around the circle, and all together in the grand central image. Each sunspot is magnetically cooled and so appears dark -- and can last from days to months. Although the featured images originated from NASA's Solar Dynamics Observatory, sunspots can be easily seen with a small telescope or binoculars equipped with a solar filter. Very large sunspot groups like recent AR 4366 can even be seen with eclipse glasses. Sunspots are still counted by eye, but the total number is not considered exact because they frequently change and break up. Last year, 2025, coincided with a solar maximum, the period of most intense magnetic activity during its 11-year solar cycle. Our Sun remains unpredictable in many ways, including when it ejects solar flares that will impact the Earth, and how active the next solar cycle will be.
LINGUISTIQUE - Les origines de la langue basque - (1/2)
Un peu plus d'un an après l'annonce de la découverte d'un mystérieux artefact vascon daté du Ier siècle av. J.C., un article pu...
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2025 May 11 The Surface of Venus from Venera 14 Image Credit: Soviet Planetary Exploration Program , Venera 14 ; Processing & Copyri...
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2022 September 26 All the Water on Planet Earth Illustration Credit: Jack Cook, Adam Nieman, Woods Hole Oceanographic Institution ; Data ...





