The Elephant's Trunk Nebula is a concentration of interstellar gas and dust within the much larger ionized gas region IC 1396 located in the constellation Cepheus about 2,400 light years away from Earth. The piece of the nebula shown here is the dark, dense globule IC 1396A; it is commonly called the Elephant's Trunk nebula because of its appearance at visible light wavelengths, where there is a dark patch with a bright, sinuous rim. The bright rim is the surface of the dense cloud that is being illuminated and ionized by a very bright, massive star (HD 206267) that is just to the east of IC 1396A. (In the Spitzer Space Telescope view shown, the massive star is just to the left of the edge of the image.) The entire IC 1396 region is ionized by the massive star, except for dense globules that can protect themselves from the star's harsh ultraviolet rays.
M16, The Eagle Nebula
Evidence from the Spitzer Space Telescope suggests that the pillars in M16 may already have been destroyed by a supernova explosion. Due to the distance of the nebula, the light from the supernova would have reached Earth between 1000 and 2000 years ago. The more slowly moving shock wave from the supernova light showing us the destruction will not reach the Earth for another millennium.