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30/09/2022

ASTRONOMY - Equinox Sunrise Around the World

 2022 September 30

See Explanation.  Clicking on the picture will download
the highest resolution version available.

Equinox Sunrise Around the World
Collage Image Copyright: Luca Vanzella

Explanation: A planet-wide collaboration resulted in this remarkable array of sunrise photographs taken around the September 2022 equinox. The images were contributed by 24 photographers, one in each of 24 nautical time zones around the world. Unlike more complicated civil time zone boundaries, the 24 nautical time zones are simply 15 degree longitude bands corresponding to 1 hour steps that span the globe. Start at the upper right for the first to experience a sunrise in the nautical time zone corresponding to Coordinated Universal Time (UTC) + 12 hours. In that time zone, the photographer was located in Christchurch, New Zealand. Travel to the west by looking down the column and then moving to the column toward the left for later sunrises as the time zone offset in hours from UTC decreases. Or, you can watch a video of September 2022 equinox sunrises around planet Earth.

29/09/2022

ASTRONOMY - DART Asteroid Impact from Space

2022 September 29
See Explanation.  Clicking on the picture will download
the highest resolution version available.

DART Asteroid Impact from Space
Image Credit: ASI / NASA

Explanation: Fifteen days before impact, the DART spacecraft deployed a small companion satellite to document its historic planetary defense technology demonstration. Provided by the Italian Space Agency, the Light Italian CubeSat for Imaging Asteroids, aka LICIACube, recorded this image of the event's aftermath. A cloud of ejecta is seen near the right edge of the frame captured only minutes following DART's impact with target asteroid Dimorphos while LICIACube was about 80 kilometers away. Presently about 11 million kilometers from Earth, 160 meter diameter Dimorphos is a moonlet orbiting 780 meter diameter asteroid Didymos. Didymos is seen off center in the LICIACube image. Over the coming weeks, ground-based telescopic observations will look for a small change in Dimorphos' orbit around Didymos to evaluate how effectively the DART impact deflected its target. 

28/09/2022

PHOTOGRAPHIE SOUS-MARINE - Maison de glace


Le ballet des phoques crabiers dans le dédale des icebergs de l’Antarctique. Les phoques trouvent ici du krill en abondance, les eaux des icebergs étant particulièrement riches en nutriments et phytoplancton.

© Greg Lecoeur, UPY 2020
FuturaSciences

ASTRONOMY - Sea and Sky Glows over the Oregon Coast

 2022 September 4

The featured image shows rock outcrops off the coast of
Oregon, USA, with blue bioluminescence in the water and the central
band of our Milky Way galaxy in the sky.
Please see the explanation for more detailed information.

Sea and Sky Glows over the Oregon Coast
Image Credit & Copyright: Rudy Montoya

Explanation: Every step caused the sand to light up blue. That glow was bioluminescence -- a blue radiance that also lights the surf in this surreal scene captured in mid-2018 at Meyer's Creek Beach in OregonUSA. Volcanic stacks dot the foreground sea, while a thin fog layer scatters light on the horizon. The rays of light spreading from the left horizon were created by car headlights on the Oregon Coast Highway (US 101), while the orange light on the right horizon emanates from a fishing boat. Visible far in the distance is the band of our Milky Way Galaxy, appearing to rise from a dark rocky outcrop. Sixteen images were added together to bring up the background Milky Way and to reduce noise.

27/09/2022

MACROPHOTOGRAPHIE - Miki Asai - La patience récompensée


La probabilité est faible pour que deux fourmis se présentent ainsi, l'une face à l'autre, pour se délecter d'une gouttelette d'eau posée sur une tige, exactement au même moment. Pourtant Miki Asai, la photographe japonaise, y a cru. Et il lui aura fallu patienter plus de sept heures durant avant que le miracle de la nature se produise sous ses yeux. Ou plutôt, devant son objectif.

Un cliché qu'on peine à croire authentique tant il semble mis en scène. C'est peut-être là aussi l'un des secrets de Miki Asai. À force d'offrir sa persévérance à la nature en gage de reconnaissance, elle finit par obtenir d'elle les plus fabuleux des cadeaux. 

© Miki Asai
FuturaSciences

VOIE LACTEE SUR TERRE - Ile de La Palma : le Mirador du Roque de los Muchachos


Le Mirador du Roque de los Muchachos est situé au sommet de l'île de La Palma, aux îles Canaries, son altitude est de 2.428 mètres. C'est l'un des meilleurs endroits au monde pour observer les étoiles. Du somment, on peut découvrir un impressionnant paysage la « Caldera de Taburiente » déclaré Parc national, un gigantesque chaudron volcanique de 1.500 mètres de profondeur, parsemé de forêts, de formations rocheuses fascinantes, d'où l'on peut apercevoir Ténérife, El Hiero et La Goma. C'est également un superbe endroit pour les randonneurs. Cette photo a été réalisée avec la technique « Time-blending ».

© Delil Geyik
FuturaSciences

ASTRONOMY - DART: Impact on Asteroid Dimorphos

 2022 September 27

DART: Impact on Asteroid Dimorphos
Video Credit: NASAJHUAPLDART

Explanation: Could humanity deflect an asteroid headed for Earth? Yes. Deadly impacts from large asteroids have happened before in Earth's past, sometimes causing mass extinctions of life. To help protect our Earth from some potential future impacts, NASA tested a new planetary defense mechanism yesterday by crashing the robotic Double Asteroid Redirection Test (DART) spacecraft into Dimorphos, a small asteroid spanning about 170-meters across. As shown in the featured video, the impact was a success. Ideally, if impacted early enough, even the kick from a small spacecraft can deflect a large asteroid enough to miss the Earth. In the video, DART is seen in a time-lapse video first passing larger Didymos, on the left, and then approaching the smaller Dimorphos. Although the video ends abruptly with DART's crash, observations monitoring the changed orbit of Dimorphos -- from spacecraft and telescopes around the world -- have just begun.

26/09/2022

MACROPHOTOGRAPHIE - Miki Asai - Soudain... la Nature se fait abstraite

Des courbes harmonieuses et des nuances de couleurs apaisantes. Cette image a tout d'une œuvre d'art abstrait que l'on pourrait trouver dans un salon dédié à la détente. Pourtant, ce n'est autre qu'une scène offerte par la nature et immortalisée par l'objectif expert de la photographe japonaise Miki Asai.

Pour plonger dans le rêve, inutile de les reconnaître. Mais il ne s'agit là ni plus ni moins que de deux pétales morts et secs, s'enfonçant dans une étendue d'eau. Et pour arrière-plan, le fond d'un écran d'ordinateur. Certes moins poétique, mais d'une redoutable efficacité au moment de parfaire le raffinement qui émane de ce cliché. 

© Miki Asai
FuturaSciences

ASTRONOMY - All the Water on Planet Earth

 2022 September 26

The featured illustration shows Earth as it might 
look without water, while small blue beads depicting all of
Earth's ocean and fresh water hover on the upper left.
Please see the explanation for more detailed information.

All the Water on Planet Earth
Illustration Credit: Jack Cook, Adam Nieman, Woods Hole Oceanographic Institution; Data source: Igor Shiklomanov

Explanation: How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius. The featured illustration shows what would happen if all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth's Moon, but slightly larger than Saturn's moon Rhea which, like many moons in our outer Solar System, is mostly water ice. The next smallest ball depicts all of Earth's liquid fresh water, while the tiniest ball shows the volume of all of Earth's fresh-water lakes and rivers. How any of this water came to be on the Earth and whether any significant amount is trapped far beneath Earth's surface remain topics of research.

25/09/2022

ASTRONOMY - The Fairy of Eagle Nebula

2022 September 25
The featured image is of a long dust filament that 
appears dark in front of a lighter background.
Please see the explanation for more detailed information.

The Fairy of Eagle Nebula
Image Credit: Image Credit: NASAESAThe Hubble Heritage Team (STScI/AURA)

Explanation: The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Featured here is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. This great pillar, which is about 7,000 light years away, will likely evaporate away in about 100,000 years. The featured image is in scientifically re-assigned colors and was taken by the Earth-orbiting Hubble Space Telescope

ASTRONOMIE - LES PLUS BEAUX ASTRES DE LA VOIE LACTéE - Antiope : l’astéroïde double

Découvert en 1866, (90) Antiope est un astéroïde qui possède la caractéristique d'être binaire . Cela signifie qu'il est constitué ...