Haley's Comet, taco salad

It's taco salad day in the cafeteria. This is very exciting in our corner of the world.

Kelsey: I told Thad that taco salad day is like the Haley's Comet of lunches. It doesn't come around nearly enough.
Me: What was the Hale Bop?
Kelsey: That was the cult who wore Reeboks. Heaven's Gate.
Thad: Look at their logo on Wikipedia. It would make a good '70s t-shirt.
Kelsey: Or theme night at the roller rink.