SCIENCE INSOLITE - On en pince pour la Nature

 

Quand on vous dit que la nature est à prendre avec des pincettes…

© Mehmet Ali Uysal-sculpteur turc

FuturaSciences

ASTRONOMY - Simulation TNG50: A Galaxy Cluster Forms

 2022 May 29

Simulation TNG50: A Galaxy Cluster Forms
Video Credit: IllustrisTNG Project; Visualization: Dylan Nelson (Max Planck Institute for Astrophysics) et al.
Music: Symphony No. 5 (Ludwig van Beethoven), via YouTube Audio Library

Explanation: How do clusters of galaxies form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. A recent effort is TNG50 from IllustrisTNG, an upgrade of the famous Illustris Simulation. The first part of the featured video tracks cosmic gas (mostly hydrogen) as it evolves into galaxies and galaxy clusters from the early universe to today, with brighter colors marking faster moving gas. As the universe matures, gas falls into gravitational wells, galaxies forms, galaxies spin, galaxies collide and merge, all while black holes form in galaxy centers and expel surrounding gas at high speeds. The second half of the video switches to tracking stars, showing a galaxy cluster coming together complete with tidal tails and stellar streams. The outflow from black holes in TNG50 is surprisingly complex and details are being compared with our real universe. Studying how gas coalesced in the early universe helps humanity better understand how our Earth, Sun, and Solar System originally formed.

MUSIQUE - Richard Strauss - Philharmonique de Berlin - Une symphonie alpine

"Eine Alpensinfonie"

ASTRONOMY - NGC 4565: Galaxy on Edge

 2022 May 26

NGC 4565: Galaxy on Edge
Image Credit & Copyright: Michael Sherick

Explanation: Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices. This sharp, colorful image reveals the galaxy's boxy, bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. NGC 4565 itself lies about 40 million light-years distant and spans some 100,000 light-years. Easily spotted with small telescopes, sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed.

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 -