PHOTOGRAPHIE - Le ciel et la mer

 Le ciel et la mer

Florent Martinez

Stelvision

ASTROPHOTOGRAPHIE - Sublimes aurores en Norvège

Cette photo du Norvégien Arild Heitmann nous dévoile un paysage qui apparaît comme enchanté. Nous sommes bien sur Terre, plus exactement au bord de la rivière Lomaas, dans la région de Skånland, en Norvège. Les lueurs d'une aurore boréale qui danse dans le ciel illuminent la végétation pétrifiée et se reflètent sur les eaux endormies et figées de la rivière. Dépaysement assuré. 

© Arild Heitmann, IAPY 2015

ASTRONOMY - The Lively Center of the Lagoon Nebula

 2022 May 25

The Lively Center of the Lagoon Nebula
Image Credit: NASA, ESA, Hubble; Processing & Copyright: Mehmet Hakan Özsaraç

Explanation: The center of the Lagoon Nebula is a whirlwind of spectacular star formation. Visible near the image center, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. A tremendously bright nearby star, Herschel 36, lights the area. Vast walls of dust hide and redden other hot young stars. As energy from these stars pours into the cool dust and gas, large temperature differences in adjoining regions can be created generating shearing winds which may cause the funnels. This picture, spanning about 10 light years, combines images taken in six colors by the orbiting Hubble Space Telescope. The Lagoon Nebula, also known as M8, lies about 5000 light years distant toward the constellation of the Archer (Sagittarius).

ASTRONOMY - A Deep Sky Behind an Eclipsed Moon

 2022 May 24

A Deep Sky Behind an Eclipsed Moon
Image Credit & Copyright: Andrei Ionut Dascalu

Explanation: The plan was to capture a picturesque part of the sky that was hosting an unusual guest. The result included a bonus — an additional and unexpected guest. The beautiful background features part of the central band of our Milky Way galaxy on the far left, and the colorful clouds of Rho Ophiuchi in the image center. The unusual guest, a dimmed and reddened Moon on the right, was expected because the image was taken during last week’s total lunar eclipse. The timing had to be right because the Moon — both before and after eclipse — would be so bright it would overwhelm the background. The unexpected guest was the bright meteor across the image center. The fleeting meteor streak was captured on only one of the 10 consecutively-captured deep-field images from La Palma in the Spanish Canary Islands, while the eclipsed Moon image was taken immediately afterwards with the same camera and from the same location. The next total lunar eclipse — also quite expected — will occur in early November.

ASTRONOMY - A Large Tsunami Shock Wave on the Sun

 2022 May 22

A Large Tsunami Shock Wave on the Sun
Image Credit: NSO/AURA/NSF and USAF Research Laboratory

Explanation: Tsunamis this large don't happen on Earth. During 2006, a large solar flare from an Earth-sized sunspot produced a tsunami-type shock wave that was spectacular even for the Sun. Pictured here, the tsunami wave was captured moving out from active region AR 10930 by the Optical Solar Patrol Network (OSPAN) telescope in New Mexico, USA. The resulting shock wave, known technically as a Moreton wave, compressed and heated up gasses including hydrogen in the photosphere of the Sun, causing a momentarily brighter glow. The featured image was taken in a very specific red color emitted exclusively by hydrogen gas. The rampaging tsunami took out some active filaments on the Sun, although many re-established themselves later. The solar tsunami spread at nearly one million kilometers per hour, and circled the entire Sun in a matter of minutes.

MUSIC - D. Gatti, Royal Concertgebouw Orchestra - Mahler 2nd symphony -

 

ASTRONOMY - A View from Earth's Shadow

 2022 May 20

A View from Earth's Shadow
Image Credit & Copyright: Maxime Oudoux

Explanation: This serene sand and skyscape finds the Dune of Pilat on the coast of France still in Earth's shadow during the early morning hours of May 16. Extending into space, the planet's dark umbral shadow covered the Moon on that date. From that location the total phase of a lunar eclipse had begun before moonset. Still in sunlight though, the International Space Station crossed from the western horizon and Earth's largest artificial moon traced the bright flat arc through the sky over 400 km above. Simply constructed, the well-planned panoramic scene was captured over a 5 minutes in a series of consecutive images.

ASTRONOMY - A Digital Lunar Eclipse

 2022 May 19

A Digital Lunar Eclipse
Image Credit & Copyright: Michael Cain

Explanation: Recorded on May 15/16 this sequence of exposures follows the Full Moon during a total lunar eclipse as it arcs above treetops in the clearing skies of central Florida. A frame taken every 5 minutes by a digital camera shows the progression of the eclipse over three hours. The bright lunar disk grows dark and red as it glides through planet Earth's shadow. In fact, counting the central frames in the sequence measures the roughly 90 minute duration of the total phase of this eclipse. Around 270 BC, the Greek astronomer Aristarchus also measured the duration of total lunar eclipses, but probably without the benefit of digital watches and cameras. Still, using geometry he devised a simple and impressively accurate way to calculate the Moon's distance in terms of the radius of planet Earth, from the eclipse duration.

MERVEILLEUX MONDE SOUS-MARIN - L'aurélie, la méduse commune

Mer Rouge : Région de Marsa Alam

Méduse aurélie (Aurelia aurita). Le diamètre de son ombrelle peut mesurer jusqu'à 40 centimètres. On distingue autour des centaines de petites tentacules.

Cette espèce vit dans toutes les mers du globe, elle est pélagique mais se rencontre aussi près des côtes.

Les animaux marins, et notamment les tortues et les dauphins qui se nourrisent de méduses confondent parfois les sacs en plastique avec elles, et s'étouffent. Cette forme de pollution est donc dangereuse pour la vie sauvage.

FuturaSciences - © Alexis Rosenfeld

ASTRONOMY - NGC 1316: After Galaxies Collide

 2022 May 17

NGC 1316: After Galaxies Collide
Image Credit & Copyright: Capture: Greg Turgeon; Processing: Kiko Fairbairn

Explanation: Astronomers turn detectives when trying to figure out the cause of startling sights like NGC 1316. Investigations indicate that NGC 1316 is an enormous elliptical galaxy that started, about 100 million years ago, to devour a smaller spiral galaxy neighbor, NGC 1317, just on the upper right. Supporting evidence includes the dark dust lanes characteristic of a spiral galaxy, and faint swirls and shells of stars and gas visible in this wide and deep image. One thing that >remains unexplained is the unusually small globular star clusters, seen as faint dots on the image. Most elliptical galaxies have more and brighter globular clusters than NGC 1316. Yet the observed globulars are too old to have been created by the recent spiral collision. One hypothesis is that these globulars survive from an even earlier galaxy that was subsumed into NGC 1316. Another surprising attribute of NGC 1316, also known as Fornax A, is its giant lobes of gas that glow brightly in radio waves.