How many planets do we expect, statistically, in the universe, have a sun and a moon with such a similar angular diameter as we do on earth? How many habitable planets? Is it possible to calculate this?

Once done, what about adding to the calculation the odds of the orbital alignment of the moon being such that there are solar eclipses.

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    $\begingroup$ From en.wikipedia.org/wiki/Exomoon "to date there have been no confirmed exomoon detections". So we have no solid data about moons outside the Solar System. But I bet the odds are very low. If aliens knew about our solar eclipses, we'd be inundated by tourists from across the galaxy. ;) $\endgroup$
    – PM 2Ring
    Apr 10 at 13:38
  • $\begingroup$ @PM2Ring maybe that's evidence that it is not rare? :) Well can we start with moons in our own solar system? $\endgroup$
    – Rabbi Kaii
    Apr 10 at 13:41
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    $\begingroup$ Not exactly an answer about the statistics, but MinutePhysics on YouTube covered many eclipse possibilities within our own solar system: there are more than you'd might expect youtube.com/watch?v=CikPFdZdY4k $\endgroup$ Apr 10 at 13:43
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    $\begingroup$ I am interested more in the congruence of angular diameters. Solar eclipses don't require this so that is just tangential. Thanks though, looks interesting 🤔 $\endgroup$
    – Rabbi Kaii
    Apr 10 at 13:58
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    $\begingroup$ Orbital alignment isn't really an issue: an eclipse-free orbit requires the orbital period to be an exact multiple of the year. Even the slightest deviation permits occasional eclipses. $\endgroup$
    – Mark
    Apr 11 at 21:06


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