Last night I went out to see the crescent moon cross in front of Alpha Tauri–Aldebaran. The Sky and Telescope report mentioned it would be visible all over the USA, the event would start at 11:03 EST and the star would emerge from behind the moon’s bright western edge about an hour later.

These events used to be of great scientific importance, timing them allowed fine tuning of the moon’s orbital elements, and gave an opportunity to measure the apparent size of the discs of stars, and to check for close binary companions. Today there are other ways of checking these things out, but it still should be fun to see a star wink out behind the dark side of the moon. Incidentally, in my spotting scope I could just barely see the dark side of the moon illuminated by earthshine, sunlight reflected off
earth’s icecaps and cloud tops.

A few years ago Saturn was occulted by the moon, and I would have loved to see it, but weather did not cooperate. Last night, I watched from about 10 PM until 10:57, when a cloud moved in just long enough to obscure the observation.

I could have waited for about an hour and watched the emergence, but I packed it in. I didn’t want to miss Saturday Night Live.

Besides, there is no dark side of the moon. It’s all dark.