Nebulae are titanic clouds of gas and dust - celestial gossamer in the spaces between the stars. They're stellar nurseries, stellar graveyards and dark constellations. Some of their mysteries have been penetrated by infrared telescopes, but the cloaking dust still keeps some secrets.
Barely visible to the unaided eye, Messier 8 (M8) – the Lagoon Nebula – lies about five thousand light years away in the constellation Sagittarius. It's over a hundred light years across, an enormous turbulent stellar nursery.
The biggest, brightest nebula in our galactic neighborhood is not for arachnophobes. It's a cosmic spider hundreds of light years across known as the Tarantula Nebula. Although the nebula is 170,000 light years away it's so luminous that it can be seen with the unaided eye.
Messier's catalog of nebulous objects begins with M1 the Crab Nebula. In 18th-century telescopes it was just a fuzzy patch, yet imaged by the Hubble Space Telescope, it's fascinating and intricate. But what is it? Why is it called the Crab Nebula? And what amazing secret does it hide?