Why is there a moon and a sun?

Answer

With just a Moon it wouldn’t be so good for us. We need a sun to have light and heat. And also to see the Moon, because it gets its light just like we do from the Sun.

If there were no Sun and no Moon, we wouldn’t be there either. Maybe that would be ‘good’ after all. As scientists it is best to remain silent about whether it is ‘good’ or ‘evil’. Our job is to determine what is there, and to try to understand the possible connections between all those things.

The sun is one of many stars in the universe. The stars are the stable (long-lasting) energy sources in the universe. It is therefore quite certain that we may say that there must be ‘a sun’ in order for something to have an intricate form of being like us. It’s also pretty clear that those intricate creatures will preferentially evolve on a planet around that star. We find that many stars do have planets. It should now be possible for our planet to have a fairly large satellite – the Moon. It is sometimes said that the Moon helped, and perhaps was necessary, for the development of life on our planet. But we are far from agreed on that.