fr/spaceweather.com

GREAT FILAMENT: It’s one of the biggest things in the entire solar system. A dark filament of magnetism measuring more than 800,000 km from end to end is sprawled diagonally across the face of the sun. NASA’s Solar Dynamics Observatory took this ultraviolet picture of the structure during the late hours of Nov. 17th:

If the filament becomes unstable, as solar filaments sometimes do, it could collapse and hit the stellar surface below, triggering a Hyder flare. Indeed, part of the filament already erupted on Nov. 16th, but Earth was not in the line of fire. A similar event today would likely be geoeffective because of the filament’s central location on the solar disk.