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, but we cannot see them.
The night sky holds clues about the life and death of stars. These clues are 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 seen through a low-power telescope, nebulae look like cotton balls. But high-power telescopes show that they are huge structures of many shapes and colors. Some nebulae signal the birth of stars. Others are leftovers from the death of stars.
