Why there are more stars in the sky some nights than the others?

It might seem as if some nights you can see a whole lot of stars twinkling everywhere, while there are only a few on other nights. However, there aren’t more stars in the sky some nights than the others, as the number of stars in the sky remains more or less the same.

This is really a question of what we see. What happens is that the state of the atmosphere differs at different times, even apart from the presence of clouds. Even when there are no clouds anywhere, the state of the air may be such that we only get to see the brightest stars out there.

 This phenomenon might be due to the presence of a lot of dust high up in the sky, or for several other reasons – nevertheless, the less bright stars cannot be seen in such cases. The temperature and the pressure of the air have their own effects in this respect.

Much of the recent advances in astronomy have been due to the fact that great new observations, including the finest telescopes in the world, have been specially built on the tops of mountains or as high up as possible. These are situated in parts of the world that are specially chosen for the clearness of the air. The higher the telescope, of course, the easier it is to spot the stars. This is because their light has to travel through less air and pollution than on lower ground.

Space is a fascinating subject in itself, with children and adults alike being interested in learning more about it.