... Bad Astronomy . ... Bitesize Astronomy . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... It's semi-common knowledge that stars twinkle and planets don't. By semi-common, I mean that a lot of folks know that, but I also mean it isn't strictly true. Stars twinkle because we see them from the bottom of a sea of air. ... These small bundles of air act like little lenses, bending light as it passes through them. ... What we see is the light from the star flickering. ...