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Lorsqu'il a réalisé la première sortie extravéhiculaire de l'Histoire, Alexei Leonov a rencontré un imprévu de taille. Sa combinaison s'est gonflée de manière anormale, l'empêchant de rentrer dans le sas. Il a alors décidé de vider en partie l'air de son scaphandre et de rentrer à l'envers !
En contrevenant aux ordres et au plan prévu, il choisit seul d’ouvrir une valve de sa combinaison pour baisser la pression à environ 1/3 de celle sur Terre. Il a également improvisé une rentrée dans la capsule la tête la première et retiré son casque plus tôt que prévu.
Wouaouh !
La nébuleuse de la trompe d'éléphant
La carte temps réel des satellites StarLink.
Whouaou ...
What is creating the structure in Comet NEOWISE's tails? Of the two tails evident, the blue ion tail on the left points directly away from the Sun and is pushed out by the flowing and charged solar wind. Structure in the ion tail comes from different rates of expelled blue-glowing ions from the comet's nucleus, as well as the always complex and continually changing structure of our Sun's wind. Most unusual for Comet C/2020 F3 (NEOWISE), though, is the wavy structure of its dust tail. This dust tail is pushed out by sunlight, but curves as heavier dust particles are better able to resist this light pressure and continue along a solar orbit. Comet NEOWISE's impressive dust-tail striations are not fully understood, as yet, but likely related to rotating streams of sun-reflecting grit liberated by ice melting on its 5-kilometer wide nucleus. The featured 40-image conglomerate, digitally enhanced, was captured three days ago through the dark skies of the Gobi Desert in Inner Mongolia, China. Comet NEOWISE will make it closest pass to the Earth tomorrow as it moves out from the Sun. The comet, already fading but still visible to the unaided eye, should fade more rapidly as it recedes from the Earth.
Magnifique
En gros, plus c'est loin du Soleil, plus ça tourne vite ! Surtout pour les grosses.
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Périodes de rotation relatives (sidérales) des différentes planètes du Système solaire. 🌍🪐 Comme vous pouvez le voir, Vénus possède la plus grande période, nécessitant 243 jours et 26 minutes pour effectuer un tour complet sur son axe.
À la fin des années 1990, John Luecke rasa une forêt au Texas pour écrire son nom sur 4 km2 et créa ainsi la plus grande signature du monde, visible depuis l'espace. La NASA utilisa cette signature pour évaluer la résolution des photographies prises depuis l'espace.
What are those spots on Jupiter? Largest and furthest, just right of center, is the Great Red Spot -- a huge storm system that has been raging on Jupiter possibly since Giovanni Cassini's likely notation of it 355 years ago. It is not yet known why this Great Spot is red. The spot toward the lower left is one of Jupiter's largest moons: Europa. Images from Voyager in 1979 bolster the modern hypothesis that Europa has an underground ocean and is therefore a good place to look for extraterrestrial life. But what about the dark spot on the upper right? That is a shadow of another of Jupiter's large moons: Io. Voyager 1 discovered Io to be so volcanic that no impact craters could be found. Sixteen frames from Voyager 1's flyby of Jupiter in 1979 were recently reprocessed and merged to create the featured image. About 43 years ago, Voyager 1 launched from Earth and started one of the greatest explorations of the Solar System ever.