美国宇航局宇航员克里斯蒂娜·科赫拍摄的照片显示了地球上难以置信的恒星轨迹。这张图片是根据11分钟内拍摄的400多张照片编辑而成的，显示了自然和人造灯光，雷暴、星星、城市灯光和火焰都在燃烧。
科克拍摄这些照片时，国际空间站——她自三月份以来一直在那里——正在纳米比亚上空朝着红海行进。美国国家航空航天局地球观测站选择时移图像作为当天的照片。
描述图像，美国宇航局说* "在地面上，像城市这样的静止特征表现为淡黄色-白色的点状条纹；每个点标记捕获的另一帧。许多较细的橙色虚线是安哥拉和刚果民主共和国燃烧的火焰。”
显示地球上恒星轨迹的延时图像。这张照片是克里斯蒂娜·科赫拍摄的400张照片。
据说在北部，雷暴覆盖了中部非洲的大部分地区。白色闪光显示闪电，而地平线上的“微弱黄绿色辉光”是一种被称为“空气辉光”的现象这是氮和氧分子被紫外线辐射和阳光激发的地方。在高层大气中，分子通过发射光子释放积累的能量——在这个过程中在大气中产生光带。在地球上方，从图像的左上角可以看到恒星轨迹。
美国国家航空航天局约翰逊航天中心的马修·奥斯沃在一份声明中说:“这一点基本上垂直于国际空间站轨道平面，根据航天器轮廓，直接在飞行器的左舷之外。”
国际空间站的旋转运动意味着最近的恒星看起来是静止的，而那些较远的恒星看起来是移动的，形成了这些圆圈。“从这张合成图像中可以看出，恒星轨迹最终会变得足够大，可以落到地球的边缘，”美国宇航局说。
这张照片是在科赫公司10月18日历史性的太空行走之后发布的。她和美国宇航局的同事杰西卡·梅尔参加了首次全女性太空行走。七个多小时后，这对夫妇在国际空间站外工作，修复空间站上出现故障的电源控制器。
在太空行走后的一次采访中，科赫说对首次全女性太空行走的巨大兴趣让这次经历变得更好。“如果说有什么不同的话，那就是它增加了这个时刻，增加了能够以这种方式为这个项目做出贡献的惊人体验，”哥伦比亚广播公司引用她的话说。
“我不会称之为[压在我们肩上的重量”，我会称之为相反的重量，一种振奋人心的重量，一种让我们尽最大努力的重量，一种让我们在那天发挥最大努力的重量，一种让我们认识到我们有天赋和机会潜在地激励未来的重量。”
NASA'S CHRISTINA KOCH CAPTURES INCREDIBLE 11 MINUTE TIME-LAPSE IMAGE OF STARS OVER EARTH
An incredible time-lapse image showing star trails over Earth has been created from images taken by NASA astronaut Christina Koch. The image, compiled from more than 400 photographs taken over 11 minutes, shows natural and artificial lights, with thunderstorms, stars, city lights and fires burning.
Kock took the photos as the International Space Station—where she has been since March—traveled over Namibia toward the Red Sea. The time-lapse image was chosen by NASA Earth Observatory as its picture of the day.
Describing the image, NASA said: "On the ground, stationary features like cities appear as pale yellow-white dotted streaks; with each dot marking another frame captured. Many of the thinner dotted lines with darker orange hues are fires burning across Angola and the Democratic Republic of the Congo."
The time-lapse image showing star trails over Earth. The image was made from 400 photographs taken by Christina Koch.
It said that towards the north, thunderstorms can be seen covering most of central Africa. The white flashes show lightning, while the "faint green-yellow glow" above the horizon is a phenomenon known as "airglow." This is where molecules of nitrogen and oxygen are energized by UV radiation and sunlight. In the upper atmosphere, the molecules release this built up energy by emitting photons—creating bands of light in the atmosphere in the process. Above Earth, star trails can be seen coming from the top left corner of the image.
In a statement, Matthew Osvog, from NASA Johnson Space Center, said: "This point is essentially normal (perpendicular) to the ISS orbital plane, directly out of the port side of the vehicle based on the spacecraft silhouettes."
The rotational movement of the ISS means that the closest stars appear stationary, while those further away appear to move, creating these circles. "As seen in this composite image, the star trails eventually get large enough to dip behind Earth's limb," NASA said.
The release of the image follows Koch's historic spacewalk on October 18. She and fellow NASA astronaut Jessica Meir took part in the first all-female spacewalk. Over seven hours, the pair worked outside the ISS to fix a failed power controller on the space station.
In an interview after the spacewalk, Koch said the huge interest in the first all-female spacewalk made the experience better. "If anything, it just added to the moment, it added to the amazing experience of being able to contribute to this program in that way," CBS quotes her as saying.
"I wouldn't call it a weight [on our shoulders], I would call it the opposite, something uplifting, something that allowed us to be our best, to bring our best to that day and to recognize that we have a gift and an opportunity to potentially inspire the future."
