地球上方的航天飞机

2022年4月17日

Shuttle Over Earth
Image Credit: NASA, Expedition 22 Crew

Explanation: What’s that approaching? Astronauts on board the International Space Station in 2010 first saw it far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship. Finally, the object revealed itself to be the Space Shuttle Endeavour, and it soon docked as expected with the Earth-orbiting space station. Pictured here, Endeavour was imaged near Earth’s horizon as it approached, where several layers of the Earth’s atmosphere were visible. Directly behind the shuttle is the mesosphere, which appears blue. The atmospheric layer that appears white is the stratosphere, while the orange layer is Earth’s Troposphere. Together, these thin layers of air — collectively spanning less than 2 percent of Earth’s radius — sustain us all in many ways, including providing oxygen to breath and a barrier to dangerous radiations from space.

Coming up Friday: Earth Day 2022

Tomorrow’s picture: steppe sky

地球上方的航天飞机
影像提供: NASA, Expedition 22 Crew

说明: 在靠近我们的是什么？于2010年，国际太空站的太空人在远处看见它。然后很快的，它就变大为暗色的剪影。随着它愈来愈近，这个剪影看来仿佛是一艘航天飞机。最后，这个物体成为奋进号航天飞机，并如预期的很快停泊在地球轨道太空站之旁。而在这幅奋进号接近地球地平线时所拍摄的主题影像里，可见看到地球大气层的数个分层。在航天飞机正后方是泛蓝的中气层。白色的是平流层，而橙色的则是地球的对流层。这些薄薄的大气分层之总厚度，虽然不到地球半径的百分之二，但在多个面向养护着我们，包括提供呼吸所需的氧气和阻挡来自太空的危险辐射。 （mesosphere 中间层； stratosphere 平流层；troposphere 对流层）

这个星期五: 2022年的地球日

明日的图片: steppe sky