In 2019, nature documentarian Hank Schyma captured a mysterious sight while photographing a storm in Tornado Alley. He saw a faint green blob over a red flash, which he later named the “green ghost.” Schyma called up sprite chaser Paul Smith, and together they investigated the phenomenon. Astrophysicists became interested and spent four years trying to understand it. They discovered that the green ghost is caused by excited atomic oxygen and asteroid dust. Amateur observers like Schyma and Thomas Ashcraft have had more success in finding the green ghost than researchers. The phenomenon is rare and difficult to see with the naked eye.
https://www.atlasobscura.com/articles/mesospheric-ghosts