亞速爾群島上空的彩虹氣流
Rainbow Airglow over the Azores
來源：Miguel Claro
(TWAN);
Rollover Annotation:
Judy Schmidt｜發表日期：2025-06-03
為什麼天空會像巨大的彩虹一樣不斷重複發光？ 空氣發光。 現在，空氣一直在發光，但通常很難看到。不過，如果有干擾--比如暴風雨即將來臨--可能會在地球大氣層中引起明顯的波紋。這些重力波是空氣中的振盪，類似於在平靜的水面上投擲石塊時產生的振盪。 幾乎沿著垂直的氣流壁長時間曝光，可能會使起伏的結構特別明顯。 好吧，那麼這些顏色源自何處呢？ 深紅色的輝光可能來自於約 87 千米高空的 OH 分子，它們被來自太陽的紫外線激發。橙色和綠色氣輝可能是由稍高處的鈉原子和氧原子產生的。 這張照片是在攀登葡萄牙亞速爾群島的皮科山時拍攝的。 地面光源來自大西洋中的法伊爾島。 透過帶狀氣流可以看到壯觀的天空，銀河系的中心帶貫穿影像中心，左上方附近可見仙女座星系 M 31 。 APOD 30 週年！： 6 月 11 日在安克雷奇舉辦免費公開講座
原文：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 green airglow is likely caused by sodium and oxygen atoms slightly higher up. The featured image was captured during a climb up Mount Pico in the Azores of Portugal. Ground lights originate from the island of Faial in the Atlantic Ocean. A spectacular sky is visible through this banded airglow, with the central band of our Milky Way Galaxy running up the image center, and M31, the Andromeda Galaxy, visible near the top left. APOD Turns 30!: Free Public Lecture in Anchorage on June 11
※ 本文由萌芽機器人自動轉貼自每日一天文圖（Astronomy Picture of the Day，APOD），原文為英文，正體中文是透過 DeepL 翻譯及 OpenCC 進行自動處理，內容僅供參考，若有任何錯誤之處還請見諒！
關於每日一天文圖：每日一天文圖網站是美國國家航空暨太空總署與密西根理工大學提供的服務，網站每天提供一張影像或圖片，並由天文學家撰寫扼要說明其特別之處。