ASTRONOMY - Galileo's Europa

 2024 March 29

Galileo's Europa
Image Credit: NASA, JPL-Caltech, SETI Institute, Cynthia Phillips, Marty Valenti

Explanation: Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon's icy surface likely hides a deep, global ocean. Galileo's Europa image data has been remastered here, with improved calibrations to produce a color image approximating what the human eye might see. Europa's long curving fractures hint at the subsurface liquid water. The tidal flexing the large moon experiences in its elliptical orbit around Jupiter supplies the energy to keep the ocean liquid. But more tantalizing is the possibility that even in the absence of sunlight that process could also supply the energy to support life, making Europa one of the best places to look for life beyond Earth. The Juno spacecraft currently in Jovian orbit has also made repeated flybys of the water world, returning images along with data exploring Europa's habitability. This October will see the launch of the NASA's Europa Clipper on a voyage of exploration. The spacecraft will make nearly 50 flybys, approaching to within 25 kilometers of Europa's icy surface.

INVENTEURS TUéS PAR LEURS CREATIONS - John Godfrey Parry-Thomas

Le Gallois John Godfrey Parry-Thomas avait un désir qui le rongeait : regagner son titre de record de vitesse sur terre, titre que lui avait arraché Malcolm Campbell. Pour y parvenir, Parry-Thomas décida de réaliser le véhicule adéquat. Il baptisa son invention Babs. Babs avait subi de nombreuses modifications et n'avait plus rien d'une voiture ordinaire. Ainsi, les chaînes reliant le moteur aux roues motrices obligeaient le conducteur à se tenir la tête inclinée du côté droit. À 270 km/h, la chaîne céda et le décapita partiellement. Il mourut instantanément. Parry Thomas and Babs, Pendine, April 1926 (Our Generation, 1938) 

© Domaine public. Edwc, Wikipedia, CC by 2.0

FuturaSciences

SANTé/MEDECINE - HISTOIRE - 1852 - L'endoscope de Desormeaux

L'endoscope a été inventé en 1852 par Desormeaux ; son utilisation a été généralisée après l'introduction de fibres optiques dans les années 1950.

© DR

FuturaSciences

ASTRONOMY - Millions of Stars in Omega Centauri

 2024 March 28

Millions of Stars in Omega Centauri
Image Credit & Copyright: Massimo Di Fusco and Mirco Turra

Explanation: Globular star cluster Omega Centauri, also known as NGC 5139, is 15,000 light-years away. The cluster is packed with about 10 million stars much older than the Sun within a volume about 150 light-years in diameter. It's the largest and brightest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way. With a yellowish hue, Omega Centauri's red giant stars are easy to pick out in this sharp, color telescopic view.

INVENTEURS TUéS PAR LEURS CREATIONS - Jimi Heselden

Dans la série des inventeurs qui se tuent avec leur invention, l'ironie est souvent de mise. Jimi Heselden, multimillionnaire britannique philanthrope, qui avait racheté la société Segway (et qui n'est donc pas le créateur à proprement parler de l'engin), est décédé à 62 ans dans sa propriété. Le millionnaire est tombé d'une falaise à bord de l'engin dont il a perdu le contrôle.

L'homme sur la photo n'est pas Jimi Heselden. L'objet roulant qu'il utilise est bien un segway. 

© GNU Free Documentation License version 1.2

ASTRONOMY - The Coma Cluster of Galaxies

 2024 March 27

The Coma Cluster of Galaxies
Image Credit & Copyright: Joe Hua

Explanation: Almost every object in the featured photograph is a galaxy. The Coma Cluster of Galaxies pictured here is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does. Although nearby when compared to most other clusters, light from the Coma Cluster still takes hundreds of millions of years to reach us. In fact, the Coma Cluster is so big it takes light millions of years just to go from one side to the other. Most galaxies in Coma and other clusters are ellipticals, while most galaxies outside of clusters are spirals. The nature of Coma's X-ray emission is still being investigated.

INVENTEURS TUéS PAR LEURS CREATIONS - Henry Winstanley

« La nécessité est mère de l'invention ». En effet, après avoir perdu non pas un mais deux de ses navires sur les récifs d'Eddystone, Winstanley, un célèbre architecte et ingénieur anglais, jugea nécessaire de construire un phare pour protéger ses navires, et ceux des autres par la même occasion. Au début des années 1700, il inventa donc le premier phare d'Eddystone lequel, selon lui, pouvait protéger les navires de la plus grande tempête. Rapidement, le ciel exhaussa ses prières et lui envoya un magnifique ouragan, le plus destructeur que la Grande-Bretagne ait connu. Le 26 novembre 1703, la tempête fit rage. Dans la matinée, lorsque le ciel se fut enfin dégagé, tout le monde put voir que le grand phare de Winstanley avait disparu, et Winstanley avec !

© Henry Winstanley (1644-1703). Domaine public

FuturaSciences

ASTRONOMY - Comet Pons-Brooks' Ion Tail

 2024 March 26

Comet Pons-Brooks' Ion Tail
Image Credit & License: James Peirce

Explanation: Comet Pons-Brooks has quite a tail to tell. First discovered in 1385, this erupting dirty snowball loops back into our inner Solar System every 71 years and, this time, is starting to put on a show for deep camera exposures. In the featured picture, the light blue stream is the ion tail which consists of charged molecules pushed away from the comet's nucleus by the solar wind. The ion tail, shaped by the Sun's wind and the comet's core's rotation, always points away from the Sun. Comet 12P/Pons–Brooks is now visible with binoculars in the early evening sky toward the northwest, moving perceptibly from night to night. The frequently flaring comet is expected to continue to brighten, on the average, and may even become visible with the unaided eye -- during the day -- to those in the path of totality of the coming solar eclipse on April 8.

ASTRONOMIE - PHOTOGRAPHIE - Connexion au ciel

18.07.2023

Jeff Graphy©

ASTRONOMY - Sonified: The Jellyfish Nebula Supernova Remnant

 2024 March 25

Sonified: The Jellyfish Nebula Supernova Remnant
Image Credit: X-ray (blue): Chandra (NASA) & ROSAT (ESA); Optical (red): DSS (NSF); Radio (green): VLA (NRAO, NSF); Sonification: NASA, CXC, SAO, K. Arcand; SYSTEM Sounds: M. Russo, A. Santaguida)

Explanation: What does a supernova remnant sound like? Although sound is a compression wave in matter and does not carry into empty space, interpretive sound can help listeners appreciate and understand a visual image of a supernova remnant in a new way. Recently, the Jellyfish Nebula (IC 443) has been sonified quite creatively. In the featured sound-enhanced video, when an imaginary line passes over a star, the sound of a drop falling into water is played, a sound particularly relevant to the nebula's aquatic namesake. Additionally, when the descending line crosses gas that glows red, a low tone is played, while green sounds a middle tone, and blue produces a tone with a relatively high pitch. Light from the supernova that created the Jellyfish Nebula left approximately 35,000 years ago, when humanity was in the stone age. The nebula will slowly disperse over the next million years, although the explosion also created a dense neutron star which will remain indefinitely.