1880

Oh for God's sake.

This is a low-effort comic, even by Randall's standards. There's only 5 points displayed-- good luck getting a statistically significant correlation out of that. Why not add in a bunch more things, like "vernal equinox", "transit of Venus", or "occultation of Jupiter"? It's not like there aren't a lot of different terms for astronomical events. Next, to the extent that there is any visible trend in this niggardly little dataset, it appears that cool-sounding things tend to be cooler to see. Not exactly a revolutionary observation, even if you think "planetary conjunction" doesn't sound cool.