3 ms·
Doesn't the orbital period tell you how far away it must be? And from knowing that, you could measure how big an angle it takes up, giving you the actual diamet
by lordnacho 5y ago
Doesn't the orbital period tell you how far away it must be? And from knowing that, you could measure how big an angle it takes up, giving you the actual diameter?
It seems harder to recruit a load of people to look at the sky.
- dr_orpheus 5y agoYes, if the orbit is circular and not eccentric, which the moon is very close to (eccentricity of 0.05). And you should be able to tell that it is close to circular by observing the relative size of the moon throughout the orbit. It will change slightly because of the eccentricity and your viewing distance to the moon but since it is far away enough these are pretty small contributing factors. I think part of the assumption is that this is still trying to use a method theoretically available to ancient Greeks and pre Brahe and Kepler before the laws of planetary motion were discovered. https://en.wikipedia.org/wiki/Orbit_of_the_Moon https://en.wikipedia.org/wiki/Orbit_of_the_Moon