... What's New? Bad Astronomy . ... News . ... The questions was: "During a flight, I saw a round rainbow shaped like a doughnut. ... However, she said that all rainbows are actually circles, and that she could not find a name for this phenomenon. ... One is that rainbows really aren't full circles. ... Basically, rainbows are due to light getting bent ("refracted") inside of raindrops. ... It's called a "glory", and is formed in a somewhat different way than rainbows. ... 2008 Phil Plait. ...