[doakes]

Is it just coincidence that from our point of view the moon looks like it's the exact same size as the sun? Or is there something else going on?

[atonse]

Yes it’s an absolutely crazy coincidence that the moon is the correct proportion to its distance that results in perfect total eclipses.

I remember learning this fact in an astronomy class and that we’re not aware of this happening anywhere else in our solar system.

[mturmon]

Part of that is that Earth's moon is quite large compared to other moons like Phobos.

Here's a nice pic of Phobos and Deimos as seen from the mast-camera of Curiosity, compared with Luna.

I remember reading an Asimov piece many years ago where he was (typically) spinning out a kind of what-if about how the large size of the moon, and the consequent majorly-obvious eclipses, influenced the importance of ancient astronomy. Not to mention other effects like tides and moonlight.

[eichin]

It's also "temporary" (moon's orbital radius increases ~4cm/year)

[lambdaba]

Yes, this is the strangest coincidence of this entire setup to me, it doesn't seem related to enabling the development of life (besides, when life arose, the position of the moon was quite different), but it was instrumental in verifying the theory of relativity, just in time for humanity to discover it.

And here's the backstory about verifying relativity: https://en.wikipedia.org/wiki/Solar_eclipse_of_May_29,_1919

[exitb]

It’s not the same size BTW. Depending on a particular configuration, the moon can be between 10% bigger and 10% smaller than sun.

[nicklecompte]

The whole idea of an annular solar eclipse is that the size is not actually exact :)

I think part of the perception that a total eclipse "perfectly" blocks the sun is that the corona has a fuzzy edge but the surface does not, so when the moon is actually larger than the sun in the sky you still see the same eerie coronal glow. In particular there's little perceptible difference between blocking 100% of the sun and blocking 105% of the sun, compared to 100% versus 95%.

[netcraft]

check out this minutephysics video that explains and also talks about other eclipses in the solar system https://youtu.be/CikPFdZdY4k?si=NXpXHz06X3nZklt4

[theodorejb]

From my perspective it's one of many evidences that our planet was intentionally created by God. I think He wanted us to experience these rare and spectacular events and use them to make astronomical discoveries.

[m0rdoor54]

Although I do not consider myself to be a very religious person I have to say, that is a very beautiful thought. It's exceedingly rare these days that any topic brought up on religion will actually give me pause and for a moment make me wonder if there is something beyond scientific coincidence. It just really goes to show how all the fanfare behind a natural phenomenon as simple as an eclipse can be such a worthwhile human experience to share.

[mullingitover]

It’s a nice to think that a creator took a break from devising all our ingeniously cruel childhood diseases to give us the occasional eclipse.

[11101010001100]

why can't it be 'accidentally' by God?

[atonse]

I just want to say that I don't understand why this is being downvoted. I'm an atheist and still see it as a wonderful (and different) way to interpret this fact. Even I am in awe of that fact, and it's only natural for crazy coincidences to feel "intentional"

[al_borland]

From what I’ve heard, the moon is also moving away from earth, ever so slightly. Something like 1cm/year. Eventually, the moon will appear too small to cover the sun and the eclipse as we know it today will be no more. But that won’t be in our lifetime. Who knows if humans will even still be around..

[make_clean]

I recall reading that is a remarkable and fortunate coincidence. Cannot find citation at the moment.

[creer]

And besides all the other remarks, both earth's and the moon's orbits are something like ellipses. So that the ratio of apparent size of the moon to apparent size of the sun is not fixed either. See annular eclipse.