Clouds of Perseus
This is a big one (click to view):
From NASA APOD:
Cosmic clouds of gas and dust drift across this magnificent panorama, spanning some 17 degrees near the southern boundary of the heroic constellation Perseus. The collaborative skyscape begins with bluish stars of Perseus at the left, but the eye is drawn to the striking, red NGC 1499. Also known as the California Nebula, its characteristic glow of atomic hydrogen gas is powered by ultraviolet light from luminous blue star Xi Persei immediately to the nebula’s right. Farther along, intriguing young star cluster IC 348 and neighboring Flying Ghost Nebula are right of center. Connected by dark and dusty tendrils on the outskirts of a giant molecular cloud, another active star forming region, NGC 1333, lies near the upper right edge of the wide field of view. Shining faintly, dust clouds strewn throughout the scene are hovering hundreds of light-years above the galactic plane and reflect starlight from the Milky Way.