尖峰石阵后方的人造卫星
Satellites Behind Pinnacles
Image Credit & Copyright: Joshua Rozells
Explanation: What are all those streaks across the background? Satellite trails. First, the foreground features picturesque rock mounds known as Pinnacles. Found in the Nambung National Park in Western Australia, these human-sized spires are made by unknown processes from ancient sea shells (limestone). Perhaps more eye-catching, though, is the sky behind. Created by low-Earth orbit satellites reflecting sunlight, all of these streaks were captured in less than two hours and digitally combined onto the single featured image, with the foreground taken consecutively by the same camera and from the same location. Most of the streaks were made by the developing Starlink constellation of communication satellites, but some are not. In general, the streaks are indicative of an increasing number of satellites nearly continuously visible above the Earth after dusk and before dawn. Understanding and removing the effects of satellite trails on images from Earth’s ground-based cameras and telescopes is now important not only for elegant astrophotography, but for humanity’s scientific understanding of the distant universe.
Astrophysicists: Browse 2,800+ codes in the Astrophysics Source Code Library
Tomorrow’s picture: the galaxy cluster next door
尖峰石阵后方的人造卫星
影像提供与版权: Joshua Rozells
说明: 影像背景中的那些条纹是什么？人造卫星的光迹。首先，这幅主题影像的前景为美丽的尖峰石阵。它是位在西澳大利亚．南邦国家公园内的不寻常尖顶石柱群，这些尖顶石柱的形成原因不明，成份为远古海贝（石灰岩），高度则与人相当。然而更吸睛的，反而是它们后方的天空。由反射阳光的低地球轨道卫星所产生、记录于不到2小时期间的这些条纹，先经过数位叠加，然后再与同一部相机在相同位置拍摄的前景影像组合成这幅主题影像。其中大多数光迹是由发展中的星链网之通信卫星所造成的，但有些不是。总而言之，这些条纹代表在黄昏后和黎明前的地球夜空中，几乎会不间断的见到数量愈来愈多的人造卫星。了解和去除影像里的卫星迹线，不仅对地基的相机和望远镜如何取得美丽的天文影像颇为重要，也对人类试图理解遥远宇宙的科学探索工作很关键。
天体物理学家: 浏览天体物理学源代码库中的2,800多个代码
明日的图片: the galaxy cluster next door
