Many people can imagine 0.04 AU and 0.21 AU just fine. One's 1/5 the distance from the Earth to the Sun, the other is 1/5 that distance. The distance ladder i

Many people can imagine 0.04 AU and 0.21 AU just fine. One's 1/5 the distance from the Earth to the Sun, the other is 1/5 that distance. The distance ladder is a good way to think about it.