ASTRONOMY - In the Arms of NGC 1097

 2022 November 16

In the Arms of NGC 1097
Image Credit & Copyright: Mike Selby, Mark Hanson

Explanation: Spiral galaxy NGC 1097 shines in southern skies, about 45 million light-years away in the heated constellation Fornax. Its blue spiral arms are mottled with pinkish star forming regions in this colorful galaxy portrait. They seem to have wrapped around a small companion galaxy above and right of center, about 40,000 light-years from the spiral's luminous core. That's not NGC 1097's only peculiar feature, though. This very deep exposure hints of faint, mysterious jets, seen to extend well beyond the bluish arms. In fact, four faint jets are ultimately recognized in optical images of NGC 1097. The jets trace an X centered on the galaxy's nucleus, but probably don't originate there. Instead, they could be fossil star streams, trails left over from the capture and disruption of a much smaller galaxy in the large spiral's ancient past. A Seyfert galaxy, NGC 1097's nucleus also harbors a supermassive black hole.

BIOMIMETISME - LA NATURE INSPIRE LA SCIENCE - Le Shinkansen : le train au bec d'oiseau

Le martin-pêcheur est un petit oiseau aquatique qui porte un bec long et fin pour pêcher des petits poissons, insectes ou batraciens dans l'eau. Ce bec a inspiré les ingénieurs japonais pour la conception du Shinkansen, le train à grande vitesse qui sillonne l'archipel nippon. Son avant profilé, bien visible sur les rames de la série 700, permet de réduire l'effet piston lorsqu'il entre à vive allure dans un tunnel, la vitesse de pointe du Shinkansen série 700 étant située entre 270 et 285 km/h.

Quand il s'y engouffre, le train génère une onde de choc bruyante qui ressemble à un bang et qui peut endommager la structure de l'ouvrage en plus de produire des nuisances sonores. Dans la nature, le bec du martin-pêcheur lui permet de fendre l'eau en faisant un minimum de remous, et s'avère tout aussi efficace pour attraper des proies volantes.

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ASTRONOMY - NGC 7380: The Wizard Nebula

 2022 November 14

NGC 7380: The Wizard Nebula
Image Credit & Copyright: Ioan Popa

Explanation: What powers are being wielded in the Wizard Nebula? Gravitation strong enough to form stars, and stellar winds and radiations powerful enough to create and dissolve towers of gas. Located only 8,000 light years away, the Wizard nebula, featured here, surrounds developing open star cluster NGC 7380. Visually, the interplay of stars, gas, and dust has created a shape that appears to some like a fictional medieval sorcerer. The active star forming region spans 100 about light years, making it appear larger than the angular extent of the Moon. The Wizard Nebula can be located with a small telescope toward the constellation of the King of Aethiopia (Cepheus). Although the nebula may last only a few million years, some of the stars being formed may outlive our Sun.

ASTRONOMY - Flying saucer crash lands in Utah desert

 2022 November 13

Flying Saucer Crash Lands in Utah Desert
Image Credit: USAF 388th Range Sqd., Genesis Mission, NASA

Explanation: A flying saucer from outer space crash-landed in the Utah desert after being tracked by radar and chased by helicopters. The year was 2004, and no space aliens were involved. The saucer, pictured here, was the Genesis sample return capsule, part of a human-made robot Genesis spaceship launched in 2001 by NASA itself to study the Sun. The unexpectedly hard landing at over 300 kilometers per hour occurred because the parachutes did not open as planned. The Genesis mission had been orbiting the Sun collecting solar wind particles that are usually deflected away by Earth's magnetic field. Despite the crash landing, many return samples remained in good enough condition to analyze. So far, Genesis-related discoveries include new details about the composition of the Sun and how the abundance of some types of elements differ across the Solar System. These results have provided intriguing clues into details of how the Sun and planets formed billions of years ago.

ASTRONOMY - Eclipse in the city

 2022 November 12

Eclipse in the City
Image Credit & Copyright: Stan Honda

Explanation: A darker Moon sets over Manhattan in this night skyscape. The 16 frame composite was assembled from consecutive exposures recorded during the November 8 total lunar eclipse. In the timelapse sequence stars leave short trails above the urban skyline, while the Moon remains immersed in Earth's shadow. But the International Space Station was just emerging from the shadow into the sunlit portion of its low Earth orbit. As seen from New York City, the visible streak of this ISS flyover starts near a star in Taurus and tracks right to left, through the belt of Orion and over Sirius, alpha star of Canis Major. Gaps along the bright trail of the fast moving orbital outpost (and an aircraft flying closer to the horizon) mark the time between individual exposures in the sequence. The trail of bright planet Mars is at the top of the frame. Pleiades star cluster trails are high over the eclipsed Moon and Empire State Building.

AVIATION IMAGINEE - L'avion du futur selon Douglas Rolfe

Avez-vous déjà imaginé votre transport du futur ? C’est l’idée du magazine Popular Science qui a laissé à Douglas Rolfe tout le loisir de créer son avion personnel. Le résultat est plutôt réaliste et bluffant, ce qui peut s’expliquer par le fait qu'en 1944 l’aviation avait déjà fait un grand bon avec la Première et la Seconde Guerre mondiale.

© Douglas Rolfe, juillet 1944, revue Popular Science

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ASTRONOMY - Blood Moon, Ice Giant

 2022 November 11

Blood Moon, Ice Giant
Image Credit & Copyright: Ryan Han

Explanation: On November 8 the Full Moon turned blood red as it slid through Earth's shadow in a beautiful total lunar eclipse. During totality it also passed in front of, or occulted, outer planet Uranus for eclipse viewers located in parts of northern America and Asia. For a close-up and wider view these two images were taken just before the occultation began, captured with different telescopes and cameras from the same roof top in Shanghai, China. Normally very faint compared to a Full Moon, the tiny, pale, greenish disk of the distant ice giant is just to the left of the Moon's edge and about to disappear behind the darkened, red lunar limb. Though only visible from certain locations across planet Earth, lunar occultations of planets are fairly common. But for this rare "lunar eclipse occultation" to take place, at the time of the total eclipse the outer planet had to be both at opposition and very near the ecliptic plane to fall in line with Sun, Earth, and Moon.

ASTRONOMY - Total lunar eclipse

 022 November 10

Total Lunar Eclipse
Image Credit: KPNO / NOIRLab / NSF / AURA / Petr Horalek (Institute of Physics in Opava)

Explanation: The beginning, middle, and end of a journey through planet Earth's colorful umbral shadow is captured in this timelapse composite image of a total lunar eclipse. Taken on November 8 from Kitt Peak National Observatory this eclipse's 1 hour and 25 minute long total phase starts on the right and finishes on the left. Reddened sunlight, scattered into the central shadow by Earth's dusty atmosphere produces the dramatic dark red hues reflected by the lunar disk. For this eclipse, additional reddening is likely due to scattering from ash lingering in the atmosphere after a large volcanic eruption in the southern Pacific earlier this year. Seen at the right and left, the Earth's shadow is still lighter along its edge though. That faint bluish fringe along the lunar limb is colored by sunlight filtered through Earth's stratospheric ozone layer.

ASTRONOMY - The Asymmetric Nebula Surrounding Wolf-Rayet Star 18

 2022 November 9

The Asymmetric Nebula Surrounding Wolf-Rayet Star 18
Image Credit & Copyright: Alex Woronow

Explanation: Why does the nebula around the star WR-18 shine brighter on one side? Also known as NGC 3199, this active star and its surrounding nebula lie about 12,000 light-years away toward the nautical southern constellation of Carina. The featured deep image has been highly processed to bring out filamentary details of the glowing gas in the bubble-shaped nebula. The nebula is about 75 light-years across. Near the nebula's center is a Wolf-Rayet star, WR-18, which is a massive, hot, short-lived star that generates an intense and complex stellar wind. In fact, Wolf-Rayet stars are known to create nebulas with interesting shapes as their powerful winds sweep up surrounding interstellar material. In this case, the bright right edge was initially thought to indicate that a bow shock was being produced as the star plowed through a uniform medium, like a boat through water. Recent measurements and analyses, however, have shown the star is not moving quickly toward the bright edge. A more likely explanation has emerged that the material surrounding the star is not uniform, but clumped and denser near the bright edge.

ASTRONOMY - Galaxies: Wild's Triplet from Hubble

2022 November 8

Galaxies: Wild's Triplet from Hubble
Image Credit: ESA/Hubble, NASA, Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, J. Dalcanton

Explanation: How many galaxies are interacting here? This grouping of galaxies is called the Wild Triplet, not only for the discoverer, but for the number of bright galaxies that appear. It had been assumed that all three galaxies, collectively cataloged as Arp 248, are interacting, but more recent investigations reveal that only the brightest two galaxies are sparring gravitationally: the big galaxies at the top and bottom. The spiral galaxy in the middle of the featured image by the Hubble Space Telescope is actually far in the distance, as is the galaxy just below it and all of the other numerous galaxies in the field. A striking result of these giants jousting is a tremendous bridge of stars, gas, and dust that stretches between them -- a bridge almost 200,000 light-years long. Light we see today from Wild's Triplet left about 200 million years ago, when dinosaurs roamed the Earth. In perhaps a billion years or so, the two interacting galaxies will merge to form a single large spiral galaxy.