SpaceX Launch Likely Caused Mysterious Spiral in Alaska Sky

A mysterious spiral seen in the sky over Alaska was caused by the launch of a Falcon 9 vehicle by SpaceX. Researchers say such patterns have become increasingly common in recent years with more commercial satellite launches. The spiral shape formed because the rocket was spinning, and the fuel was probably released from Falcon 9's second stage as it was taking steps to de-orbit so it could safely lower in the atmosphere. The event was probably caused by excess fuel released during the launch, and it doesn't take much material to create such a bright-looking cloud.