We joined the other Key West tourists, and who knows maybe a few locals, for an spontaneous sunset viewing party. I know if I lived around there, I’d be out at least occasionally, taking in something that never gets old. No organizer at all, just people collecting at the right place at the right time to see the disk of the sun transition from yellow to red and other colors, as it visibly creeps lower toward the horizon. Down the sun went, in its predictable splendor, and then — green.

I’m pretty sure what I saw was an inferior-mirage flash, to use a technical term I learned later. I checked later, finding that one characteristic of such a flash is an oval of light lasting no more than 2 seconds (I’d say it was no more than a single second, if that). They tend to happen when the surface is warmer than overlaying air, and close to sea level.

All that fits for the green flash — a variety of green intense and completely new to me — as the sun set our first day in Key West. The flash came exactly as the top edge of the disk of the sun dipped below the horizon. You have to, I believe, be looking straight at the exact right place at exactly the right moment to see it, as I was, by pure accident. I’d heard about green flashes for a long time, but I’d never seen one. A really long time: I remember them being mentioned during a planetarium show in San Antonio as a kid in the early ’70s.

We hadn’t come to Mallory Square to see a green flash or any other meteorological optical phenomena. We hadn’t even come to see the sun go down. We just happened to arrive at Mallory, a large public plaza near the north end of Duval St. and right at the water’s edge, just at the right time, after gadding about that part of Key West.

It’s a mildly festive place around sunset. Also, people are waiting. The sun was not to be hurried.

Lots of people around, not an overwhelming crowd, more of a happy milling of vacation-goers.

Live entertainment was on hand.

The star attraction, however – make that the solar attraction – was the sunset. Mallory Square has a fine view of the westward horizon, where sea and sky come together like a hazy kiss out on the ocean.

So now I’ve seen a green flash. A total solar eclipse (two, actually), lunar eclipses, the transit of Venus, double rainbows, ground-to-sky lightning, sun- and moondogs, meteors, planets through telescopes including the moons of Jupiter and Saturn, the impressive whisp of the Milky Way in a dark sky, the Southern Cross and the Magellanic Clouds – add a green flash to the list.

But what other cool things to see in the sky that so far have eluded me? The aurora, for one. Aurora borealis would be great, and certainly more doable than aurora australis, but wouldn’t seeing the Southern Lights be a kick? I think I first learned about it in a Carl Barks Scrooge McDuck comic, and never forgot.