The Little Dipper—also known as the Little Bear or Ursa Minor—is a useful gauge to determine how much light pollution affects your local sky. The Dipper is formed by seven relatively faint stars, and the four faintest of these can be blotted out with very little moonlight or street lighting.

Polaris, the bright North Star, lies at the end of the handle, and remains in very nearly the same spot all night long while the other stars in the sky appear to circle around it. This is because only one full-moon width separates Polaris from the north celestial pole, the point around which the entire sky revolves.

To find your way to Polaris, you might need some help from the Big Dipper, an asterism invulnerable to all but the very worst light pollution. The dippers are arranged so that when one is upright, the other is upside down, with their handles extending in opposite directions. The Big Dipper, however, is by far the more impressive of the two, appearing as a bright, long-handled pot, while the Little Dipper resembles a small, dim ladle.

Draw a line between the Big Dipper's so-called "pointer" stars—Dubhe and Merak—at the front edge of the bowl, extend it about five times, and you'll eventually arrive in the vicinity of Polaris. There is a popular misconception that the North Star is the brightest star in the sky, when in fact it only ranks 49th.