The Pole Star stands still

If the Earth is spinning, shouldn't the stars also seem to move across the sky, like the Sun?

Activity 12.3: on an early evening between March and May, find the Big Dipper (also called Saptarishi, seven bright stars shaped like a ladle) and, if you can see it, the Pole Star (Dhruva Tara). Note your location and the date: the whole activity must be done on one night.

Draw the Big Dipper's position compared with the Pole Star, and write the time. If you can't see the Pole Star, draw it against a fixed tree or building instead.

After two hours, look again. Has it moved? Draw it and note the time. Do it once more after another two hours.

You find the Big Dipper seems to circle round the Pole Star.

Why does the Pole Star stay put? Because the Earth's axis points almost exactly at the Pole Star (in the Northern Hemisphere). Think of the centre of a spinning plate: everything on the rim goes round, but the middle stays in place. So the Pole Star looks nearly still, and all the other stars seem to turn around it.

Like the Sun, the Moon also seems to rise in the East and set in the West, for the same reason: the Earth rotates from West to East.

Astrophotographers take long-exposure photographs, keeping the camera shutter open for a long time. In such a photo, each star's apparent movement shows up as a curved line, part of a circle, called a star trail.