How far away is the Sun?

Chapitre 1Light takes timeYou know your street and your city. But how far is it to the next big house in the neighborhood — the Sun? Nobody has ever been there, and nobody has sent a tape measure. And yet we know its average distance to within a few meters.0 niveaux sur 1

Chapitre 2Measuring the skyNobody has walked to the Sun or a star. So how do we know how far they are? With a thumb, a planet crossing the Sun and a lot of patience.0 niveaux sur 3

1. Niveau 1Light takes its time
2. PRÊTNiveau 2Measuring with your thumb
3. PRÊTNiveau 3A light-year is a distance
4. PRÊTNiveau 4Closer means faster