Part of the show The Naked Scientists Christmas Special
When Iíve been watching planets and stars in the night sky, why is it that the stars appear to be twinkling much more than the planet?
Itís actually because planets are fairly large. You can actually see them on the back of your eye. Itís a bit like having 100 stars all very close togther. All those 100 stars will be twinkling. On average some of them are going to be twinkling brighter and some of them are going to be darker than average. They tend to twinkle less when you see them all together. If 20 of them are going to be brighter and 20 of them are going to be darker then on average itís not going to twinkle very much.