Horsehead Nebula. It's a dark nebula of thick dust, so it can only be seen against the lighter background on the left. The Herschel Space Observatory image on the right is in infrared which can penetrate the dust. Herschel Spaces, Dark Nebula, Horsehead Nebulas, Lighter Backgrounds, Finals Frontier, Mona Evans, Google Search, Observatori Image, Simply Incredible
Filigree and Shadow — Wispy tendrils of hot dust and gas glow brightly in this ultraviolet image of the Cygnus Loop Nebula, taken by NASA’s Galaxy Evolution Explorer. The nebula lies about 1,500 light-years away, and is a supernova remnant, left over from a massive stellar explosion that occurred 5,000-8,000 years ago... Image Credit: NASA/JPL-Caltech
The Witch Head Nebula. It glows from light reflected from bright supergiant Rigel - Orion's left foot! Although Rigel is blue, the nebula is blue because the dust tends to absorb the red part of the light and reflect the blue. (Image: George Greany)
The "Peony Nebula," as discovered by NASA's Spitzer Space Telescope. This three color infrared composite shows 3.6-micrometre light in blue, 8-micrometre light in green, and 24-micrometre light in red. The Peony nebula is the reddish cloud of dust in and around the white circle, surrounding the Peony nebular star.
A dying star is throwing a cosmic tantrum in this combined image from NASA's Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.