Some people are just different and have vastly different concepts of importance.
For the VAST majority most people, rarity in and of itself has no importance. Three black dots appearing on an orange blob that themselves have no effects on the lives, health, or entertainment of people on Earth will get almost no coverage. If it shows up on the local news, they'll focus on the people who gathered at the local observatory (Check out these nerds, eh?) and not the event itself.
Even rare silly calendar dates (11/11/11) have more significance because people impose major importance (however irrational) on those rare, tangible events (http://goo.gl/Wg1Q23).
I wasn't yet born when Neil et al. first tread on the moon, but I've seen the video. I've seen video of people watching it live. I understood the awe because of the example it served a marvel of achievement. I'll probably be shown an image of the 3 black dots on Jupiter. And like Venus' transit of the sun, it's "neat" at best, but will not affect people.
How about some more appropriate context.
Mars Spirit Rover Landing: "Remember when the first Mars Rover landed and started sending images back from Mars? It was SO AMAZING to see photographs from another planet!" (http://youtu.be/MWk-umZm86U?t=7m38s)
Jupiter Gets Beat Up: "Remember when Shoemaker-Levy crashed into Jupiter? That was a really big boom!" (http://www.youtube.com/watch?v=CiLNxZbpP20)
Jupiter is Temporarily and Slightly Shadowed: "Remember when three of Jupiter's moon all cast a visible shadow on Jupiter at the same time? Ya. It happened."