How to find the Big Dipper, and from it the North Star

Hop one: the Dipper

The Big Dipper is not a whole constellation but a famous part of one, Ursa Major. Its seven stars are all about the same brightness, so the shape stands out even from a town.

From most of the United States it never sets: it just circles the North Star. In spring and summer evenings it is high, almost overhead; in autumn and early winter evenings it swings low and sits near the northern horizon, where trees and roofs can hide it. Look later in the night, or before dawn, and it has climbed.

Hop two: the pointers

Find the bowl's outer edge, the two stars farthest from the handle. Draw a line from the bottom one through the top one and keep going. About five of those gaps along, there is a star on its own, not very bright: Polaris.

Polaris is not the brightest star in the sky, which surprises many people. It is famous because it hardly moves. Earth's axis points almost straight at it, so every other star seems to turn around it through the night.

What the North Star tells you

It marks north, all night, every night. And how high it sits is your latitude: in Denver, about 40° north, it is four fists up; in Miami, about 26°, between two and three; in Anchorage, about 61°, six.

Polaris is also the end of the handle of the Little Dipper, a fainter ladle that needs a darker sky.

Make it a game

Once your child can find the Dipper, ask them to find it again at bedtime a few hours later. It will have turned, swinging around the North Star like the hand of a slow clock, going the other way round from a real clock's hands. Draw it on paper at 7 pm and again at 9 pm to see.

Older children can measure the North Star's height with fists and compare it with your town's latitude on a map. The two numbers match to within a fist or so, which is how sailors once found their way north of the equator.

Then use the Dipper's handle: follow its curve away from the bowl and you reach a bright orange star, Arcturus, high in spring evenings.