The star we call the North Star, or Polaris, is a star that, by coincidence, happens to be located almost directly over the North Pole of the Earth. All other stars appear to "move" through the sky as the Earth spins and the night goes on. The North Star, because it is almost directly above the North Pole (which is at the center, or axis, of the Earth’s spinning motion), does not "move". It remains in the same position in the sky.For anyone at the North Pole the North Star appears directly overhead (or 90 degrees up from the horizon). For all other people who live north of the equator it is in the northern direction, and exactly as many degrees up from the horizon as that location’s distance in degrees from the equator of the Earth (this is the same as that location’s latitude). From the equator the North Star would appear always right at the horizon (0 degrees from the horizon, the same as the equator's latitude). Therefore, the North Star not only guides us to which direction is north, it also guides us to what our current latitude is (e.g. in the San Francisco Bay Area the North Star is 38 degrees above the horizon, the same as this area's latitude).
The North Star can be found through the help of the Big Dipper. If you look at the last two stars in the bowl end, and, in an imaginary way, extend the line between those two stars about 5 times the distance between them (or 3 fist widths with arm extended), you find the North Star. It is a somewhat dim star, but fairly easy to find because, with the eye, there appear to be no other stars right around it.
If you are wondering what people south of the equator do to guide them with directions, they are out of luck. There is no equivalent "South Star".
Next month: The Day When We Will No Longer Have the North Star.
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