Thor‘s Helmet

NGC 2359 is an emission nebula located 12,000 lightyears away in Canis Major. It's also known as Thor's Helmet, given its similarity in shape to the Norse god's famous headwear.

The nebula is produced by a massive, hot Wolf-Rayet star emitting a stream of charged particles known as a stellar wind that's expanding outwards to produce an interstellar bubble.

This bubble is interacting with molecular clouds nearby, causing the ionising of radiation that gives the nebula its glow.