来自国际太空站的实况影像
影像来源与版权:NASA, UStream, HDEV Project

说明:如果你现在能漂浮在地球上空,这可能是你会见到的景象。在2014年,SpaceX(太空探索)公司的飞龙号太空舱为轨道上的国际太空站(ISS)进行补给,同时也递交了一批高解析的地球观景(HDEV)相机,用来拍摄和回传地球实况影像。上面的画面(如果连结正常运作的话),会在四部不同指向相机所拍摄的实况影片之间切换。从视野中漂过的景观,会包括白云、棕褐色的陆块和蔚蓝的海洋。如果太空站下方的地表是夜间的话,上面的影像会呈黑色;不过,太空站为期90分钟的快速轨道,会让处在黑夜的时间缩减成45分钟。国际太空站现行的位置,可用网络查到。如果上面的视屏是灰色的,那可能是刚好处在切换相机的空档或者国际太空站的通讯暂时中断。随着高解析地球观景计画持续进行,从监控影片的品质变化,可评估高能辐射的影响、哪种相机效能最好、与及哪些地球景观最受欢迎。
翻译:“每日一天文图”成大物理分站

A Live View from the International Space Station
Image Credit & Copyright: NASA, UStream, HDEV Project

Explanation: If you were floating above the Earth right now, this is what you might see. In 2014, a robotic SpaceX Dragon capsule that delivered supplies to the Earth-orbiting International Space Station (ISS) also delivered High Definition Earth Viewing (HDEV) cameras that take and transmit live views of Earth. Pictured here, when working, is the live video feed that switches between four cameras, each pointed differently. Watch white clouds, tan land, and blue oceans drift by. The featured live view will appear black when it is nighttime on the Earth below, but the space station’s rapid 90-minute orbit compresses this dark time into only 45 minutes. The present location of the ISS above the Earth can be found on the web. If the video appears gray, this indicates that the view is either being switched between cameras, or communications with the ISS is temporarily unavailable. As the HDEV project continues, video quality will be monitored to assess the effects of high energy radiation, which types of cameras work best, and which Earth views are the most popular.
Astronomy Picture of the Day 06/02/2019