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Affichage des articles dont le libellé est ASTRONOMY - A Perseid Below. Afficher tous les articles
Affichage des articles dont le libellé est ASTRONOMY - A Perseid Below. Afficher tous les articles

09/08/2024

ASTRONOMY - A Perseid Below

 2024 August 9

See Explanation.  Clicking on the picture will download
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A Perseid Below
Image Credit: Ron Garan, ISS Expedition 28 CrewNASA

Explanation: Denizens of planet Earth typically watch meteor showers by looking up. But this remarkable view, captured on August 13, 2011 by astronaut Ron Garan, caught a Perseid meteor by looking down. From Garan's perspective on board the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust from comet Swift-Tuttle. The vaporizing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is near frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at a meteor shower? You're in luck, as the 2024 Perseid meteor shower is active now and predicted to peak near August 12. With interfering bright moonlight absent, this year you'll likely see many Perseid meteors under clear, dark skies after midnight.

08/08/2021

ASTRONOMY - A Perseid Below

 2021 August 8

The picture shows a Perseid meteor as imaged from the International Space Station. 
Please see the explanation for more detailed information.

A Perseid Below
Image Credit: NASA ISS Expedition 28 CrewRon Garan

Explanation: Earthlings typically watch meteor showers by looking up. But this remarkable view, captured on August 13, 2011 by astronaut Ron Garan, caught a Perseid meteor by looking down. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at a meteor shower? You're in luck, as the 2021 Perseids meteor shower peaks this week. This year, even relatively faint meteors should be visible through clear skies from a dark location as the bright Moon will mostly absent.

PLANTES FASCINANTES - Un bourdon ? non - c'est l'orchidée Orphrys bombyliflora

Une fois n'est pas coutume, cette orchidée Orphrys bombyliflora peut être observée près de chez nous : dans le sud de l'Europe, en ...