Why do stars stay in space?

Answer

I just answered a question why everything doesn’t stand still, and now you ask me why everything doesn’t fall down…

You have to remember that not only the stars stay in space, but also ourselves! The Earth is a sphere in space, just like the other planets and the stars are.

All those spheres (and less regular bodies in between) attract each other, and the closer you get to one of them, the harder you are attracted to it. Close to the Earth you only really feel the attraction of the Earth, and you fall into that Earth, so down. The Earth especially feels the pull of its closest star, the Sun. She doesn’t stand out, though, because she’s been given enough speed to keep spinning past it all the time.

A star far from us hardly feels the Earth. She does feel other stars (usually much more than one). When close to the Sun, the Sun is one of many. Stars therefore move by the attraction of many stars at the same time, and thus rarely move towards a single particular star. And they move quite fast, at speeds of tens of kilometers per second. But they are also far apart: at ten kilometers per second it takes more than a hundred thousand years to get to the closest star after the Sun! Because of these great distances, we hardly see the movements of the stars reflected in the sky. But by comparing today’s observations with maps made by the ancient Greeks, we find that some stars have moved in the sky over distances about the diameter of the Moon.