With My Own Eyes: Lunar Occultation of Antares

Yesterday, at 9:33 PM, I was out in the driveway, sitting in my lawnchair, staring up at the moon—and the tiny dot of the red supergiant star, Antares. I was waiting for the exact moment when the dark edge of the moon would move in front of the star and it would wink out.

These occultations, where the moon moves in front of something, are fairly common. If I had a good enough telescope I could probably see something like it every clear night. What made this one special is that Antares is a bright star, the sixteenth brightest, I think. This is an image I took of Scorpio a few nights ago with my iPhone. Antares is the bright star in the heart of the constellation.

Constellation Scorpio

I alternated watching the closing gap with my binoculars and my bare eyes. The moon was bright enough that many of the stars of Scorpio were washed out by the light haze, but Antares was still bright enough to see unaided.

And then, suddenly, Antares wasn’t there anymore. The moon had eclipsed it. This was what I’d come out here, braving the mosquitoes to see.

Here is the point. I saw, with my bare eyes, that Antares just vanished. It hadn’t faded away. It just blinked out. This tells me several things. This PROVES several things. Direct eyeball observation with no chance for faked video or anything like that showed me how abrupt the light from Antares vanished.

I love moments like this, where I get to see the universe directly. You know, if the moon had an atmosphere, then the starlight would fade away, not blink out. Yes, I know I’ve read that the moon has no atmosphere, but now I’ve seen it with my own eyes.

If Antares was large, like a planet, that could show a disk, then the light would have faded as well as the dark edge slowly crept across the tiny disk. That didn’t happen either. Antares, like the other stars, are so far away that they don’t show a disk except with really huge telescopes. I know that now, with my own eyes.

And in a more mundane revelation, my SkySafari 5 Pro software, already many years out of date, has proven accurate enough for me to preview and project the exact time of the occulation down to the second. I guess I don’t have to go out and buy the latest and greatest version just yet.

I love seeing the universe with my own eyes, it centers me.