XKCD Web Comic #1071: Exoplanets (described)

A web comic of romance,
sarcasm, math, and language.

Scene: A large circle made up of colored dots of various sizes. The smallest are about the size of a period and the largest are about the size of the end of a pencil eraser. The largest are red, with the sizes ranging down through brown, gold, blue, green, and then gray. Near the top of the circle, amongst the dots,  it says “All 786 Known Planets (as of June 2012) to Scale (some planet sizes estimated based on mass.)” Beneath the words, a box is drawn around one set of the dots–two gold dots, two blue dots, three green and one gray. The box is labeled “This is our solar system.” Beneath that it says, “The rest of these orbit other stars and were only discovered recently. Most of them are huge because those are the kind we learned to detect first, but now we’re finding that small ones are actually more common. We know nothing abut what’s on any of them. With better telescopes, that would change. This Is An Exciting Time.”

Hover text: Planets are turning out to be so common that to show all the planets in our galaxy, this chart would have to be nested in itself–with each planet replaced by a copy of the chart–at least three levels deep.

Warning: This comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).