法国上空的气辉

法国上空的气辉

ByNASA中文

2023年2月15日 Airglow Sky over France Image Credit & Copyright: Julien Looten Explanation: This unusual sky was both familiar and unfamiliar. The photographer’s mission was to capture the arch of the familiar central band of our Milky Way Galaxy over a picturesque medieval manor. The surprise was that on this January evening, the foreground sky was found glowing in a beautiful but unfamiliar manner. The striped bands are called airglow and they result from air high in Earth’s atmosphere being excited by the Sun’s light and emitting a faint light of its own. The bands cross the entire sky — their curved appearance is due to the extremely wide angle of the camera lens. In the foreground lies Château de Losse in southwest France. Other familiar…

西藏上空的气辉涟漪

西藏上空的气辉涟漪

ByNASA中文

2022年11月20日 Airglow Ripples over Tibet Image Credit & Copyright: Jeff Dai Explanation: Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured here. The unusual pattern is created by atmospheric gravity waves, waves of alternating air pressure that can grow with height as the air thins, in this case about 90-kilometers up. Unlike auroras powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction. More typically seen near the horizon, airglow keeps the night sky from ever being completely dark. Tomorrow’s picture: butterfly sky 西藏上空的气辉涟漪 图像提供与版权: Jeff Dai（戴建峰） 说明:…

银河周围的彩色带状气辉

银河周围的彩色带状气辉

ByNASA中文

2022年3月13日 Colorful Airglow Bands Surround Milky Way Image Credit & Copyright: Xiaohan Wang Explanation: Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however — like an approaching storm — may cause noticeable rippling in the Earth’s atmosphere. These gravity waves are oscillations in air analogous to those created when a rock is thrown in calm water. Red airglow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun, while orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up. While driving near Keluke Lake in Qinghai Provence in China a few years ago, the photographer originally…

亚速尔群岛上空的彩虹气辉

亚速尔群岛上空的彩虹气辉

ByNASA中文

2021年04月18日 Rainbow Airglow over the Azores Image Credit & Copyright: Miguel Claro (TWAN); Rollover Annotation: Judy Schmidt Explanation: Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however — like an approaching storm — may cause noticeable rippling in the Earth’s atmosphere. These gravity waves are oscillations in air analogous to those created when a rock is thrown in calm water. The long-duration exposure nearly along the vertical walls of airglow likely made the undulating structure particularly visible. OK, but where do the colors originate? The deep red glow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun. The orange and…