The bright red regions in this wide-field view come from ionized hydrogen. Due to the prevalence of hydrogen in the galactic disk and its relatively low energy of ionization, many emission nebulae appear red due to the strong emissions of the Balmer series. The Milky Way's disk and dust lanes dominate the rest of the image. Cygnus Constellation, Humboldt State Park. Learn more about the HiMARC technology behind this photograph in the research section.