APOD: 2022 April 17

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.

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The mission was to document night-flying birds, but it ended up documenting a beautiful sky. The mosaic was taken over the golden fields in Portugal in 2020. The central band of the Milky Way galaxy glowed over the night sky from such a dark location. The sky had more. The clouds were like golden ribbons. On the far left, there was the planet Mars, while on the far right, there were the planets Jupiter and Saturn. The bright star Vega can be found near the top of the image, while the distant and faint AndromedaGalaxy can be seen to the left. There are several planets in the pre-dawn sky as the current month progresses.