A cosmic cloud of gas and dust nicknamed the “California Nebula”. It gets that name from its outline that slightly resembles the state.
The nebula, 1500 light years from Earth, is completely invisible to the human eye due to its extremely low surface brightness. Long exposure images like this show it to be 2.5 times larger than the full moon in the nighttime sky. The color comes from Hydrogen that glows deep in the red portion of the visual spectrum.
And while California is the third largest state in America, the nebula size is truly astronomical. It would fit at least 50 of our solar systems from end to end over its length.