A Short History of Nearly Everything

by Bill Bryson

Most schoolroom charts show the planets coming one after the other at neighbourly intervals – the outer giants actually cast shadows over each other in many illustrations – but this is a necessary deceit to get them all on the same piece of paper. Neptune in reality isn’t just a little bit beyond Jupiter, it’s way beyond Jupiter – five times further from Jupiter than Jupiter is from us, so far out that it receives only 3 per cent as much sunlight as Jupiter. Such are the distances, in fact, that it isn’t possible, in any practical terms, to draw the solar system to scale. Even if you added lots of fold-out pages to your textbooks or used a really long sheet of poster paper, you wouldn’t come close. On a diagram of the solar system to scale, with the Earth reduced to about the diameter of a pea, Jupiter would be over 300 metres away and Pluto would be two and a half kilometres distant (and about the size of a bacterium, so you wouldn’t be able to see it anyway). On the same scale, Proxima Centauri, our nearest star, would be 16,000 kilometres away. Even if you shrank down everything so that Jupiter was as small as the full stop at the end of this sentence, and Pluto was no bigger than a molecule, Pluto would still be over 10 metres away.

Scale of solar system