My 20-month old loves all things spherical, especially the moon, so the game was up anyways as he was staring at the moon in it's full splendour before the skedded eclipse overtook it.
So there was no way we'd not let him watch. Besides, it was easy. The show presented itself outside our condo window.

Not sure if he understood why it disappeared slowly though. Before when a cloud would interrupt his moon-gazing, he 'd probably think it was a celestial plot to keep him away from his most prized and yearned for planetary body.

As for momentous occasions, celestial or not, I used to think that the kid HAD to be there: it was a once in a lifetime, blah blah blah....But that just engendered a lot of stress on my part and you know what, at his age, he probably didn't care and will never remember......(watch I'll regret that statement in a few years...)

Just relax and everyone will have a good time.

Very Sony-fied!