For thousands of years, humans have gazed up at the night sky and wondered about the sparkling lights above. Long before television or the internet, people used the stars to tell stories and find their way across the ocean. By "connecting the dots" between bright stars, they created pictures in the sky known as constellations. Today, astronomers recognize 88 official constellations that divide the entire sky into a giant map.

One of the most famous constellations is Orion, the Hunter. You can spot him easily in the winter sky by looking for three bright stars in a straight line, which make up his "belt." Another well-known group of stars is Ursa Major, also called the Great Bear. Part of this constellation forms the Big Dipper, which looks like a giant soup ladle. For centuries, travelers used the two stars at the edge of the Big Dipper’s bowl to point toward Polaris, the North Star. This helped sailors and explorers stay on course even in the middle of a dark, empty sea.

It is important to remember that the stars in a constellation only look like they are close together from our perspective on Earth. In reality, some stars in a single pattern might be hundreds of light-years further away than others. If you were to travel to a different part of the galaxy, the shapes we see today would look completely different because your point of view would change!

Did you know that not everyone sees the same constellations? Depending on where you live—the Northern or Southern Hemisphere—you will see a different set of stars. Also, the shapes of constellations change over very long periods. Because stars are constantly moving through space, the Big Dipper will look more like a flat line in about 50,000 years. Even though the sky seems still, it is always changing in its own slow, cosmic way.