Did you ever see an Iridium flare? For two decades until 2019, these communication satellites would become dazzlingly bright for a second or so in the night sky. I used to see them by accident before discovering that some websites and apps could forecast precisely when and where they would occur. I got so obsessed with Iridium flares that I would build my stargazing sessions around them. Eventually, I started trying to take night sky images just as they flared. Why? In a long exposure, the flare produced a diamond-shaped light. It was beautiful. I carried on doing the same for the International Space Station (ISS), capturing it racing across the night sky, again to a tight pre-determined schedule.
Then SpaceX came along. After launching the non-flaring replacements for Iridium in May 2019, SpaceX began launching its Starlink satellites into low Earth orbit. There were complaints about their brightness from astrophotographers, who saw their streaks in long exposure photos, but for stargazers, they were initially a delight. Each time SpaceX launched a batch of satellites into orbit on a Falcon 9 rocket, a string of moving lights could be seen in the night sky. It got called a "train" by some because it resembled a freight train racing through the sky. To me, it looked like an alien invasion. During COVID-19, glimpsing Starlink trains was something new to do (I spent hours on Heavens Above). Now it's something to actively avoid.
