Due north, halfway up the dome of the clear night sky, glimmers the North Star, Polaris. It’s not very bright; its fame comes instead from its odd coincidence of position. It stands almost exactly above Earth’s north pole. This means that Earth’s axis points almost straight at it, so as Earth turns, it looks to us like the whole sky is turning around Polaris while we’re standing still. Don’t get dizzy.
That’s what it looks like not just at the North Pole, but anywhere you live in the Northern Hemisphere. In the Boston area, 48 degrees of latitude away from the North Pole, we see Polaris 48 degrees north of our zenith, and the whole sky seems to rotate around that off-kilter point. Full story for BostonGlobe.com subscribers.