AERONAUTIQUE - LES INVENTIONS QUI N'ONT JAMAIS VOLE - La machine volante du professeur Wellner

Très jolie, la machine volante du professeur Wellner manque pourtant de praticité. La navette protégeant les passagers est reliée à deux cylindres. Elle aurait pu être très utile pour voyager… si elle avait réussi à voler.

FuturaSciences

ANIMAUX - Le Pétrel de Hall

 

Le Pétrel de Hall vit dans les océans du Sud entre l'Argentine et l'Australie. Ce grand oiseau marin mesure jusqu'à 2,10 mètres d'envergure, soit presque autant qu'un albatros considéré comme le plus grand oiseau du monde.

FuturaSciences

ASTRONOMY - HESS Telescopes Explore the High-Energy Sky

 2023 September 6

HESS Telescopes Explore the High-Energy Sky
Credit & Copyright: Video Credit & Copyright: Jeff Dai (TWAN), H.E.S.S. Collaboration;
Music: Ibaotu catalog number 1044988 (Used with permission)

Explanation: They may look like modern mechanical dinosaurs, but they are enormous swiveling eyes that watch the sky. The High Energy Stereoscopic System (H.E.S.S.) Observatory is composed of four 12-meter reflecting-mirror telescopes surrounding a larger telescope housing a 28-meter mirror. They are designed to detect strange flickers of blue light -- Cherenkov radiation --emitted when charged particles move slightly faster than the speed of light in air. This light is emitted when a gamma ray from a distant source strikes a molecule in Earth's atmosphere and starts a charged-particle shower. H.E.S.S. is sensitive to some of the highest energy photons (TeV) crossing the universe. Operating since 2003 in Namibia, H.E.S.S. has searched for dark matter and has discovered over 50 sources emitting high energy radiation including supernova remnants and the centers of galaxies that contain supermassive black holes. Pictured in June, H.E.S.S. telescopes swivel and stare in time-lapse sequences shot in front of our Milky Way Galaxy and the Magellanic Clouds -- as the occasional Earth-orbiting satellite zips by.

ASTRONOMY - Blue Supermoon Beyond Syracuse

 2023 September 5

Blue Supermoon Beyond Syracuse
Credit & Copyright: Kevin Saragozza

Explanation: The last full moon was doubly unusual. First of all, it was a blue moon. A modern definition of a blue moon is a second full moon to occur during one calendar month. Since there are 13 full moons in 2023, one month has to have two -- and that month was August. The first full moon was on August 1 and named a Sturgeon Moon. The second reason that the last full moon was unusual was because it was a supermoon. A modern definition of supermoon is a moon that reaches its full phase when it is relatively close to Earth -- and so appears a bit larger and brighter than average. Pictured, the blue supermoon of 2023 was imaged hovering far behind a historic castle and lighthouse in Syracuse, Sicily, Italy.

VEGETAUX - Forêt magique

Malgré l'aspect irréel de ces champignons, ces derniers, des lépiotes élevées (Macrolepiota procera) ne donnent pas d’hallucinations. Ils jouent en revanche un rôle essentiel dans l'écosystème, en créant un réseau de racines souterraines et en produisant de la matière organique.

© AGORASTOS PAPATSANIS

AERONAUTIQUE - LES INVENTIONS QUI N'ONT JAMAIS VOLE - L’hélicoptère imaginaire de Gabriel de la Landelle

Souvent attribué à Clément Ader, le terme « aviation » revient en réalité à Guillaume Joseph Gabriel de la Landelle, à qui l'on doit aussi une superbe invention : l'hélicoptère. Il construira le prototype, censé fonctionner avec de la vapeur, en 1861. Il ne s'agit pas encore vraiment de celui que nous connaissons aujourd'hui mais plutôt d'un navire à hélice.

© Gabriel de la Landelle

ASTRONOMY - Cygnus: Bubble and Crescent

 2023 September 4

Cygnus: Bubble and Crescent
Credit & Copyright: Abdullah Al-Harbi

Explanation: As stars die, they create clouds. Two stellar death clouds of gas and dust can be found toward the high-flying constellation of the Swan (Cygnus) as they drift through rich star fields in the plane of our Milky Way Galaxy. Caught here within the telescopic field of view are the Soap Bubble (lower left) and the Crescent Nebula (upper right). Both were formed at the final phase in the life of a star. Also known as NGC 6888, the Crescent Nebula was shaped as its bright, central massive Wolf-Rayet star, WR 136, shed its outer envelope in a strong stellar wind. Burning through fuel at a prodigious rate, WR 136 is near the end of a short life that should finish in a spectacular supernova explosion. Discovered in 2013, the Soap Bubble Nebula is likely a planetary nebula, the final shroud of a lower mass, long-lived, Sun-like star destined to become a slowly cooling white dwarf. Both stellar nebulas are about 5,000 light-years distant, with the larger Crescent Nebula spanning about 25 light-years across. Within a few million years, both will likely have dispersed.

ASTRONOMY - Comet Schwassmann-Wachmann 3 Fragments

 2023 September 3

Comet Schwassmann-Wachmann 3 Fragments
Credit: NASA, ESA, H. Weaver (JHU / APL), M. Mutchler and Z. Levay (STScI)

Explanation: Periodic comet 73P/Schwassmann-Wachmann 3 has broken up at least twice. A cosmic souffle of ice and dust left over from the early solar system, this comet was first seen to split into several large pieces during the close-in part of its orbit in 1995. However, in the 2006 passage, it disintegrated into dozens of fragments that stretched several degrees across the sky. Since comets are relatively fragile, stresses from heat, gravity and outgassing, for example, could be responsible for their tendency to break up in such a spectacular fashion when they near the hot Sun. The Hubble Space Telescope recorded, in 2006, the featured sharp view of prolific Fragment B, itself trailing a multitude of smaller pieces, each with its own cometary coma and tail. The picture spans over 3,000 kilometers at the comet's distance of 32 million kilometers from planet Earth.

ASTRONOMY - NGC 7023: The Iris Nebula

 2023 September 2

NGC 7023: The Iris Nebula
Image Credit & Copyright: Lorand Fenyes

Explanation: These cosmic clouds have blossomed 1,300 light-years away in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers. Still, this deep telescopic image shows off the Iris Nebula's range of colors and symmetries embedded in surrounding fields of interstellar dust. Within the Iris itself, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the reflection nebula glow with a faint reddish photoluminescence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula contains complex carbon molecules known as PAHs. The dusty blue petals of the Iris Nebula span about six light-years.

ASTRONOMY - The Crew-7 Nebula

 2023 August 31

The Crew-7 Nebula
Image Credit & Copyright: Michael Seeley

Explanation: Not the James Webb Space Telescope's latest view of a distant galactic nebula, this illuminated cloud of gas and dust dazzled early morning spacecoast skygazers on August 26. The snapshot was taken about 2 minutes after the launch of a Falcon 9 rocket on the SpaceX Crew-7 mission, the seventh commercial crew rotation mission for the International Space Station. It captures drifting plumes and exhaust from the separated first and second stage illuminated against the still dark skies. Near the center of the image, within the ragged blueish ring, are two bright points of light. The lower one is the second stage of the rocket carrying 4 humans to space in a Crew Dragon spacecraft. The bright point above is the Falcon 9 first stage booster orienting itself for the trip back to Landing Zone-1 at Cape Canaveral, planet Earth.