It's consensus that the very similar apparent sizes of the Moon and the Sun as seen from Earth is a coincidence (as already answered in this site).
This provides us with almost exact total solar eclipses and other interesting sights, such as this one shared in Fermat's Library's tweet:
Here's a great photo of the ISS by J. Mccarthy.
The reason why the ISS keeps its relative size against both the Sun and the Moon is due to a remarkable coincidence: the diameter of the Moon is 400x smaller than the diameter of the Sun, but it is also 400x closer to us!
This state of affairs is not permanent, of course - as the moon keeps retreating from us - but total solar eclipses are estimated to keep occurring for the next 600 million to 1 billion years from now.
We're currently unable to answer how big this coincidence is, since we don't have enough statistical data on planet-moon systems yet, however we do have models of solar system formation.
So my question is, irrespective of the presence of intelligent beings or the possibility of actually observe total eclipses:
- According to our knowledge of planet formation, how unlikely is this coincidence?