Reply #69: The phases of the moon don't give any evidence of heliocentricity [View All]

[muriel_volestrangler]

They are evidence that the Moon shines entirely from reflected light of the Sun, but they'd look exactly the same in a geocentric model.

The phases of Venus (first observed, as far as we know, by Galileo) are another matter. They are good evidence of the relative movement of the Sun and Venus, and imply Venus orbits round the Sun. But from the Earth, the Moon and Sun appear to move in an orbit around the Earth, and you can't distinguish what is 'stationary' without very careful measurement of things like the parallax of stars.