SpaceX’s latest Falcon 9 launch turned the night sky red. It was not visible to the naked eye, but appeared in long-exposure images taken by astrophotographers.
“I photographed the Milky Way behind some rock silhouettes when suddenly one of my pictures had this distinctive red spot right in front of the core, which wasn’t there in the previous picture taken 3 minutes ago,” wrote one of them, named David Johnson, on Facebook.
“I was really upset because it ruined my picture, but I thought it would go away. Instead, it grew in several other images and spread so that it covered a large part of the southeastern sky, “he added.
Johnson later realized that he had taken the first red-colored image at virtually the same time as the aforementioned SpaceX launch. But before he knew what thing he was most likely to look at, he had no idea what it might be, he said. “It scared me a little,” he admitted in an interview with The Washington Post.
Experts later confirmed that his suspicions were probably correct. Oxygen ions generated by Falcon 9’s second stage react with other molecules in the night sky, which in turn excites electrons and creates a red glow.
“These glows are probably the exhaust gases from the second stage of the rocket, which cause a rapid recombination of the ionosphere,” he explained physicist Jeff Baumgardner of Boston University.