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17/10/2024

ASTRONOMY - The Clipper and the Comet

 2024 October 17

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

The Clipper and the Comet
Image Credit & CopyrightBen Cooper (Launch Photography)

Explanation: NASA's Europa Clipper is now headed toward an ocean world beyond Earth. The large spacecraft is tucked into the payload fairing atop the Falcon Heavy rocket in this photo, taken at Kennedy Space Center the day before the mission's successful October 14 launch. Europa Clipper's interplanetary voyage will first take it to Mars, then back to Earth, and then on to Jupiter on gravity assist trajectories that will allow it to enter orbit around Jupiter in April 2030. Once orbiting Jupiter, the spacecraft will fly past Europa 49 times, exploring a Jovian moon with a global subsurface ocean that may have conditions to support life. Posing in the background next to the floodlit rocket is Comet Tsuchinsan-ATLAS, about a day after the comet's closest approach to Earth. A current darling of evening skies, the naked-eye comet is a vistor from the distant Oort cloud

16/10/2024

LES NUAGES DIEUX DU CIEL - Stratocumulus au parc national des Arches (États-Unis)

Stratocumulus stratiformis perlucidus castellanus cumulogenitus. Photo prise dans l'Utah, au parc national des Arches (États-Unis).

© Bernhard Mühr, Der Karlsruher Wolkenatlas, www.wolkenatlas.de

ASTRONOMY - Colorful Aurora over New Zealand

 2024 October 16

A night sky is shown that appears mostly red due to pervasive
aurora. In the foreground is covered by watery grasslands. Clouds 
are visible above the horizon. Thin green aurora are visible 
toward the top of the frame. In the background one can find the Moon,
the LMC, SMC, Venus, a meteor, and the band of our Milky Way galaxy.
Please see the explanation for more detailed information.

Colorful Aurora over New Zealand
Image Credit & Copyright: Tristian McDonald

Explanation: Sometimes the night sky is full of surprises. Take the sky over Lindis PassSouth IslandNew Zealand one-night last week. Instead of a typically calm night sky filled with constant stars, a busy and dynamic night sky appeared. Suddenly visible were pervasive red aurora, green picket-fence aurora, a red SAR arc, a STEVE, a meteor, and the Moon. These outshone the center of our Milky Way Galaxy and both of its two satellite galaxies: the LMC and SMC. All of these were captured together on 28 exposures in five minutes, from which this panorama was composed. Auroras lit up many skies last week, as a Coronal Mass Ejection from the Sun unleashed a burst of particles toward our Earth that created colorful skies over latitudes usually too far from the Earth's poles to see them. More generally, night skies this month have other surprises, showing not only auroras -- but comets.

15/10/2024

VILLES BIONIQUES DU FUTUR - L’arche bionique de Taiwan : la nature à la verticale


Dans le parc Gateway de Taichung, à Taiwan, cette tour est comme une forêt dans la ville. Des prairies et des jardins s'étalent en palier sur 390 m de hauteur dans un bâtiment autosuffisant, grâce aux énergies solaire et éolienne. On s'y promène pour apprécier la nature et pour trouver une vision panoramique sur la mégalopole. La tour sert aussi pour les relais de télécommunications.

© Vincent Callebaut

MUSIC - Strauss : Morgen (extrait de 4 Lieder) | Musica Sancta Ensemble

"Morgen"

LES NUAGES DIEUX DU CIEL - Qu'est-ce qu'un cirrus ?


Cirrus fibratus undulatus et cirrus fibratus, en Allemagne. Le cirrus est un nuage appartenant à l'étage supérieur (aux latitudes tempérées, sa base se situe entre 6.000 et 12.500 m de hauteur avec une épaisseur de l'ordre de 300 m). Il est constitué de bancs, de bandes ou de filaments séparés, blancs le plus souvent, qui revêtent un aspect fibreux ou un éclat soyeux (les deux apparences pouvant se conjuguer). Il n'est pas associé aux précipitations.

© Bernhard Mühr, Der Karlsruher Wolkenatlas, www.wolkenatlas.de

ASTRONOMY - Animation: Comet Tsuchinshan-ATLAS Tails Prediction

 2024 October 15

Animation: Comet Tsuchinshan-ATLAS Tails Prediction
Credit & Copyright: Nico Lefaudeux

Explanation: How bright and strange will the tails of Comet Tsuchinshan-ATLAS become? The comet has brightened dramatically over the few weeks as it passed its closest to the Sun and, just three days ago, passed its closest to the Earth. C/2023 A3 (Tsuchinshan–ATLAS) became of the brightest comets of the past century over the past few days, but was unfortunately hard to see because it was so nearly superposed on the Sun. As the comet appears to move away from the Sun, it is becoming a remarkable sight -- but may soon begin to fade. The featured animated video shows how the comet's tails have developed, as viewed from Earth, and gives one prediction about how they might further develop. As shown in the video, heavier parts of the dust tail that trails the comet have begun to appear to point in nearly the opposite direction from lighter parts of the dust tail as well as the comet's ion tail, the blue tail that is pushed directly out from the Sun by the solar wind.

14/10/2024

INVENTIONS A L'HORIZON 2050 - Certaines plantes deviendront éternelles


Aujourd'hui, 70% des grandes cultures nécessitent de ressemer des graines chaque année : ce sont des plantes "annuelles". Or, selon les auteurs d'un article paru dans le magazine Science en juin 2010, les plantes vivaces (qui repoussent naturellement chaque année) nécessitent cinq fois moins d'eau et 35 fois moins d'engrais que les cultures classiques pour pousser.

Leur objectif est donc de transformer les semences classiques (le blé notamment) par transgénèse. "Ce serait la plus grande avancée de l'agriculture depuis 10 000 ans", s'enthousiasment les auteurs de l'article. Ils prévoient un aboutissement des recherches pour 2030.

JournalDuNet

ASTRONOMY - Comet Tsuchinshan-ATLAS Over the Lincoln Memorial

 2024 October 14

The Lincoln Memorial monument in Washington, DC, USA
is pictured from afar. Behind the monument is a sunset-colored
pink sky. In the sky, on the upper left, is a white streak that
is a comet. 
Please see the explanation for more detailed information.

Comet Tsuchinshan-ATLAS Over the Lincoln Memorial
Credit & Copyright: Brennan Gilmore

Explanation: Go outside at sunset tonight and see a comet! C/2023 A3 (Tsuchinshan–ATLAS) has become visible in the early evening sky in northern locations to the unaided eye. To see the comet, look west through a sky with a low horizon. If the sky is clear and dark enough, you will not even need binoculars -- the faint tail of the comet should be visible just above the horizon for about an hour. Pictured, Comet Tsuchinshan-ATLAS was captured two nights ago over the Lincoln Memorial monument in Washington, DCUSA. With each passing day at sunset, the comet and its changing tail should be higher and higher in the sky, although exactly how bright and how long its tails will be can only be guessed.

13/10/2024

ASTRONOMY - Aurora Timelapse Over Italian Alps

 2024 October 13

Aurora Timelapse Over Italian Alps
Video Credit & Copyright: Cristian Bigontina

Explanation: Did you see last night's aurora? This question was relevant around much of the world a few days ago because a powerful auroral storm became visible unusually far from the Earth's poles. The cause was a giant X-class solar flare on Tuesday that launched energetic electrons and protons into the Solar System, connecting to the Earth via our planet's magnetic field. A red glow of these particles striking oxygen atoms high in Earth's atmosphere pervades the frame, while vertical streaks dance. The featured video shows a one-hour timelapse as seen from Cortina d'Ampezzo over Alps Mountain peaks in northern Italy. Stars from our Milky Way Galaxy dot the background while streaks from airplanes and satellites punctuate the foreground. The high recent activity of our Sun is likely to continue to produce picturesque auroras over Earth during the next year or so.

ASTRONOMIE - Galaxies - NGC 4414

Une galaxie spirale . (photo HST, APOD 09/09/1999)