This was
your sky.

Creature Aurora Over Norway

This striking aurora over Tromsø, Norway, appeared like a creature in the Halloween night sky. The vivid green and purple colors are a result of high-altitude oxygen and nitrogen atoms reacting to incoming electrons from the Sun. Auroras are caused by solar wind particles interacting with Earth's magnetic field and atmosphere. The birch trees in the foreground provide a terrestrial anchor to this celestial display.