On a clear night, it is possible to see more than 3,000 stars with the naked eye. There are billions of other stars up there in the sky, but we cannot see them.
The nighttime sky holds clues about the life and death of stars. These clues are found in fuzzy-looking clouds of glowing gas sprinkled with black dust. These clouds are called nebulae (NEB-u-lie). The word nebula (singular form of nebulae) comes from the Latin word for cloud. When viewed through a low-power telescope, nebulae look like cotton balls. But high-power telescopes show that nebulae are huge multishaped, multicolored structures. Some nebulae signal the birth of stars, while others are relics from the death of stars.
