What is an Orrery used for?
They are a teaching aid for showing students how the various planets revolve and rotate. With an Earth/Moon/Sun system model you can answer all these questions by just turning the handle.. • Why we have day and night • What a year is • What a lunar month is • Why there is summer and winter • Why there is ‘six months day’ at the North pole • How and why Solar and Lunar eclipses happen • Why eclipses don’t happen very often • Why there are phases of the Moon • Why we always see the same face of the Moon • Why the tropics and the Arctic circles are where they are • Why we have to have a leap year every fourth year.
