Pipe Nebula 
We’re naturally attracted to the bright stars that speckle the night sky. But one special sight in the night is dark. If you can get far enough from city lights, you can see it as a large, dark cloud. And although it’s visible to the unaided eye, it’s mysterious and little explored.
It’s called the Pipe Nebula, and its outline really does resemble its namesake. The nebula appears against the glow of the Milky Way in the constellation Ophiuchus. This evening it’s to the left of the bright orange star Antares, which is low in the east at nightfall.
The nebula is centered about 450 light-years from Earth, and it stretches across 55 light-years of space.
The nebula is a “molecular cloud,” so called because it consists mainly of molecules of hydrogen gas. But dust in the cloud darkens the gas and blocks our view of the stars beyond.
Molecular clouds are dense enough to give birth to new stars. But the Pipe Nebula has barely done so — and no one knows why. The nebula is massive enough to give birth to 10,000 stars as heavy as the Sun, but so far it’s spawned only a couple of dozen stars.
Because the Pipe Nebula lacks the flash of regions that abound with stellar newborns, astronomers have only recently begun studying it. Perhaps it’s in an early stage of evolution, and it’ll ultimately produce hundreds or even thousands of stars. Or perhaps outside forces will tear it apart — snuffing out the Pipe before it’s able to live up to its star-making potential.
Script by Ken Croswell, Copyright 2012