When we look at planets in our solar system, one thing becomes obvious very quickly: they are all roughly round. Earth, Mars, Jupiter, Saturn, and the others may differ in size, colour, and composition, but none of them are shaped like cubes, pyramids, or flat disks. So why are planets round in the first place? The answer comes down to gravity. ("President's Column #13: Flat Earthers and the rise of conspiracy theories" – Hokkaido University) Gravity pulls matter toward the c