English: While I was observing under the dark skies of White Mound County Park in Sauk County, Wisconsin with some other astronomers, we noticed a cloud coming to interrupt our observing. However, we quickly realized this was not an ordinary cloud, and rushed to get our cameras to try to figure out what it was. Our first instinct was that it was some unusual aurora, but as we watched it evolve I realized this was a propellant dump from the upper stage of a rocket: specifically, Zhuque-2E flight Y5, launched a few hours earlier from China into a sun-synchronous orbit. The cloud of dumped propellant brightened as it slowly moved north, away from Earth's shadow on this spring evening, resembling the tail of a comet. The red lights at the lower right are where some of the visual observers set up the equipment for the night.