ASTRONOMY - Mars: Moon- Craters and Volcanos

 2024 September 9

Mars: Moon, Craters, and Volcanos
Image Credit: ESA, DLR, FU Berlin, Mars Express; Processing & CC BY 2.0 License: Andrea Luck; h/t: Phil Plait

Explanation: If you could fly over Mars, what might you see? The featured image shows exactly this in the form of a Mars Express vista captured over a particularly interesting region on Mars in July. The picture's most famous feature is Olympus Mons, the largest volcano in the Solar System, visible on the upper right. Another large Martian volcano is visible on the right horizon: Pavonis Mons. Several circular impact craters can be seen on the surface of the aptly named red planet. Impressively, this image was timed to capture the dark and doomed Martian moon Phobos, visible just left of center. The surface feature on the lower left, known as Orcus Patera, is unusual for its large size and oblong shape, and mysterious because the processes that created it still remain unknown. ESA's robotic Mars Express spacecraft was launched in 2003 and, among many notable science discoveries, bolstered evidence that Mars was once home to large bodies of water.

ASTRONOMY - M31: The Andromeda Galaxy

2024 September 8

M31: The Andromeda Galaxy
Image Credit: Subaru (NAOJ), Hubble (NASA/ESA), Mayall (NSF);
Processing & Copyright: R. Gendler & R. Croman

Explanation: The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy. Even at some two and a half million light-years distant, this immense spiral galaxy -- spanning over 200,000 light years -- is visible, although as a faint, nebulous cloud in the constellation Andromeda. A bright yellow nucleus, dark winding dust lanes, and expansive spiral arms dotted with blue star clusters and red nebulae, are recorded in this stunning telescopic image which combines data from orbiting Hubble with ground-based images from Subaru and Mayall. In only about 5 billion years, the Andromeda galaxy may be even easier to see -- as it will likely span the entire night sky -- just before it merges with, or passes right by, our Milky Way Galaxy. 

INVENTIONS A L'HORIZON 2050 - Des arbres lampadaires pour éclairer les rues

L'éclairage public représenterait 8% de la consommation électrique mondiale. Des étudiants de l'Université de Cambridge (Royaume-Uni) ont imaginé le remplacement des lampadaires par... des arbres lumineux. Ils ont réussi à introduire dans le génome d'une cellule un gène issu de la luciole ou d'une bactérie sous-marine, capable de restituer de la lumière.

D'après leurs calculs, un arbre ne consommerait ainsi que 0,02% de l'énergie qu'il absorbe par photosynthèse pour émettre suffisamment de lumière afin d'éclairer une rue. Le projet a remporté le premier prix de la compétition IGEM 2010, qui récompense les meilleures innovations en génie génétique.

JournalDuNet

ASTRONOMY - Small Moon Deimos

 2024 September 7

Small Moon Deimos
Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA

Explanation: Mars has two tiny moons, Phobos and Deimos, named for the figures in Greek mythology Fear and Panic. Detailed surface views of smaller moon Deimos are shown in both these panels. The images were taken in 2009, by the HiRISE camera on board the Mars Reconnaissance Orbiter spacecraft, NASA's long-lived interplanetary internet satellite. The outermost of the two Martian moons, Deimos is one of the smallest known moons in the Solar System, measuring only about 15 kilometers across. Both Martian moons were discovered in 1877 by Asaph Hall, an American astronomer working at the US Naval Observatory in Washington D.C. But their existence was postulated around 1610 by Johannes Kepler, the astronomer who derived the laws of planetary motion. In this case, Kepler's prediction was not based on scientific principles, but his writings and ideas were so influential that the two Martian moons are discussed in works of fiction such as Jonathan Swift's Gulliver's Travels, written in 1726, over 150 years before their discovery.

PHENOMENES METEOROLOGIQUES - Un orage enragé

Graham Newman était sur le rivage sur la côte nord-ouest de l'Australie, à un peu plus de 5 km de l'orage lorsqu'il a pris cette photo. L'un des multiples éclairs frappait alors le super-tanker de 240 mètres de long, Guanabura. Quelques minutes plus tard, le photographe dut courir jusqu'à sa voiture pour se protéger de la foudre qui l'encerclait. « Je venais juste de fermer la porte de la voiture lorsque la foudre a frappé tout près » raconte-t-il.

Belle et terrifiante, la foudre frappe l’océan et le super-tanker Guanabura, au large de la côte nord-ouest australienne, près du champ pétrolier de l’île de Barrow.

© Graham Newman, Royal Photographic Society

FuturaSciences

PLANTES FASCINANTES - L'Orchis d'Italie recouverte de petits hommes nus

L'Orchis d'Italie est largement répandue dans les régions méditerranéennes, principalement en Europe méridionale, mais aussi en Asie mineure et en Afrique du Nord. Elle se caractérise par la forme de ses fleurs ressemblant à des hommes nus ! Ses couleurs varient du vert pâle au pourpre, avec des nuances de rose et de violet.

© Elkspera Adobe stock

ASTRONOMY - Ringed Ice Giant Neptune

 2024 September 6

Ringed Ice Giant Neptune
Image Credit: NASA, ESA, CSA, STScI, NIRCam

Explanation: Ringed ice giant Neptune lies near the center of this sharp near-infrared image from the James Webb Space Telescope. The dim and distant world is the farthest planet from the Sun, about 30 times farther away than planet Earth. But in the stunning Webb view, the planet's dark and ghostly appearance is due to atmospheric methane that absorbs infrared light. High altitude clouds that reach above most of Neptune's absorbing methane easily stand out in the image though. Coated with frozen nitrogen, Neptune's largest moon Triton is brighter than Neptune in reflected sunlight, seen at the upper left sporting the Webb telescope's characteristic diffraction spikes. Including Triton, seven of Neptune's 14 known moons can be identified in the field of view. Neptune's faint rings are striking in this space-based planetary portrait. Details of the complex ring system are seen here for the first time since Neptune was visited by the Voyager 2 spacecraft in August 1989.

MUSIC - Carl Orff - Ô Fortuna ~ Carmina Burana

"Ô Fortuna ~ Carmina Burana"

PHENOMENES METEOROLOGIQUES - Un pont entre ciel et terre fait de pluie et de grêle

Photo prise depuis les hauteurs de la forêt de Macclesfield par une fin d’après-midi froide d’hiver. Avalanche de grêle sur la plaine. 

© Mark Boardman, Royal Photographic Society

Sur la photo on peut voir de la pluie et de la grêle se déverser par torrent tout près du radiotélescope de Jodrell Bank, dans la plaine autour de Macclesfield, petite ville du centre du Royaume-Uni.

FuturaSciences

ASTRONOMY - NGC 247 and Friends

 2024 September 5

NGC 247 and Friends
Image Credit & Copyright: Acquisition - Eric Benson, Processing - Dietmar Hager

Explanation: About 70,000 light-years across, NGC 247 is a spiral galaxy smaller than our Milky Way. Measured to be only 11 million light-years distant it is nearby though. Tilted nearly edge-on as seen from our perspective, it dominates this telescopic field of view toward the southern constellation Cetus. The pronounced void on one side of the galaxy's disk recalls for some its popular name, the Needle's Eye galaxy. Many background galaxies are visible in this sharp galaxy portrait, including the remarkable string of four galaxies just below and left of NGC 247 known as Burbidge's Chain. Burbidge's Chain galaxies are about 300 million light-years distant. NGC 247 itself is part of the Sculptor Group of galaxies along with shiny spiral NGC 253.