The California Nebula . ... Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. ... Also known as NGC 1499 , the classic emission nebula is around 100 light-year s long. On the featured image , the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away ( ionized ) by energetic starlight. ...