Welcome to another Science Explainy Bit episode of the Urban Astronomer Podcast. Today we try to figure out just what an "orbit" actually is. Is it really as simple as they said in primary school? How does gravity, which normally pulls things down, work to keep the Moon in space? Download this episode now, to find the answer, and also learn a little about my upcoming appearance at ScopeX!
This turns out to be quite a simple topic - much simpler than why planets are always round, which we covered last month. In fact I struggled to stretch the core idea out long enough to fill an episode! All I really want to do here is explain how things stay up and why they go around, without resorting to the inaccurate "Centrifugal Force" explanation. You know the one? Where you ask people to fill a bucket, and then spin it around? The bucket swings around them without spilling any water, and then you wave your hands and say "That's how orbits work, except that there's no handle on the bucket, just gravity".
The truth, however, is so much cooler than that, so if you want to skip straight ...