The North Star, officially named Polaris, is a beacon for navigation because it is situated almost directly above the Earth’s North Pole, a point known as the north celestial pole. Because of this alignment, Polaris appears to remain nearly motionless while all other stars in the northern sky seem to circle around it. This stability means that finding Polaris is equivalent to finding true north, making it an invaluable tool for travelers throughout history.
Identifying the Big Dipper
The most reliable guide to finding Polaris is the star pattern known as the Big Dipper. The Big Dipper is not a constellation itself, but an asterism—an informal grouping of seven bright stars within the larger constellation Ursa Major, or the Great Bear. These stars trace the outline of a ladle or saucepan, featuring a bowl of four stars and a handle of three stars. It is visible throughout the year in the Northern Hemisphere, earning it the designation of a circumpolar pattern.
Using the Pointer Stars to Locate Polaris
The Big Dipper’s utility as a celestial guide comes from the two stars on the outer edge of its bowl, known as the “pointer stars”: Merak and Dubhe. Merak is at the bottom of the bowl, and Dubhe is the star farthest from the handle. To locate Polaris, draw an imaginary line starting from Merak, passing through Dubhe, and extending straight out into space. This line acts as a precise arrow pointing directly toward the North Star. You must extend the line approximately five times the distance that separates Merak and Dubhe. Following this projection, you will arrive at Polaris, a star that is notably brighter than the surrounding stars.
The Little Dipper’s Connection to the North Star
Once you have located Polaris using the Big Dipper, you have found the end of the handle of the Little Dipper. The Little Dipper is an asterism within the constellation Ursa Minor, forming a smaller, fainter ladle shape. Polaris serves as the brightest of its seven stars. The other six stars that make up the Little Dipper are considerably dimmer and difficult to see, especially with light pollution. This is why the Big Dipper is the preferred tool for the initial discovery of the North Star.