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Amazing answers all around, thank you!
Yep, it’s totally a coincidence that we live during a period when that is true. As the Moon moves slowly farther away from the Earth, this will no longer be true.
Yes, it is a coincidence. The Sun is roughly 400 times the size of the Moon, and roughly 400 times further away from Earth than the Moon is. So it happens to be about the same size in the sky.
If you look at other moons of the solar system, this is not the case, and so you would not get these near-perfect eclipses. For example, the largest moons of Jupiter all have a larger apparent size (when seen from Jupiter) than the Sun does, and so it wouldn’t line up so nicely, they’d completely block the sun. Other moons are smaller than the apparent size of the sun and would instead transit the Sun without eclipsing it.
As far as I know there’s no particular benefit to having this coincidence, it’s just nice.
Yes it is a coincidence.
The sun is roughly 400 times larger than the moon.
But it is also 400 times further away.
So, to us on the ground, they happen to look the same size and you can get a perfect total solar eclipse.
If the moon was smaller, or further away, it wouldn’t be able to completely cover the sun.
The moon is actually moving away from
The earth right now by a couple centimeters a year on average, so in several Tens of thousands of years is possible that the moon will no long be able to totally eclipse the sun from earth
It’s coincidence, and we’re right on the border of the moon being too far.
The orbit of the moon is just oval enough that sometimes it is too far and we get something call an [annular eclipse](https://en.wikipedia.org/wiki/Solar_eclipse#/media/File:Annular_Eclipse._Taken_from_Middlegate,_Nevada_on_May_20,_2012.jpg) where the moon doesn’t block the sun all the way.
Though other times it’s close enough to block the sun all the way.
Yes, it is a pretty cool coincidence. Also, the distance the moon is from earth is changing, so it didn’t always (and won’t always) line up so perfectly.
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It is a coincidence. We just happen to live during the period of time where the angular diameters of the Sun and Moon are, sometimes, nearly equal, giving us the opportunity to view a “total” solar eclipses.
However, not all eclipses are total. The moon’s orbit is an ellipse, aka not perfectly circular, which means that its distance from the Earth varies over time. When it’s farther from Earth, it appears smaller in the sky, and if an eclipse happens when it appears small like this, we called it an Annular Solar Eclipse. In the middle of the event, the sun appears as a solid ring of light with the dark moon right in the middle – not large enough to completely block the sun like during a Total Solar Eclipse.
The moon orbited closer to the Earth in the past, and it will continue to drift further away in the future. Eventually, it will get so far and appear so small that it will never be able to fully block the sun like it can now, so we could still see annular eclipses, but we would never experience a total eclipse again.
We’re pretty lucky that we live during the time when we can! I missed my opportunity to view one back in 2017 due to a job interview. I’ve vowed to not let myself miss the next one.
There are many interesting relationships between the sun, moon, and earth.
– It would take 108 moons, stretched end to end, to cover the distance between the earth and the moon.
– It would take 108 suns, stretched end to end, to cover the distance between the earth and the sun.
– The moon’s radius is 1,080 miles. The sun’s radius is 432,000 miles. Notice how 108 * 4 = 432.
– There are 864,000 seconds in one day, or 432,000 seconds in half of one day (12 hours); notice how these are the same as the sun’s radius and diameter in miles.
– The moon takes 30 days to fully encircle the earth (this is one moonth). There are 24 hours in each day, making 432,000 hours in one moonth, or 2,592,000 seconds in one moonth.
– The fixed stars in the night sky (the constellations of the zodiac) fully encircle the earth every 25,920 years, there’s that number 25920 again.
– The sun precesses against the fixed stars at a rate of 1 degree every 72 years, approximately the average human lifespan. At this rate, it takes 25,920 years for the sun to fully precess through a complete 360 deg circle of the constellations.
– The moon’s radius of 1,080 miles, when multiplied by 24 (the number of hours in a day) equals 4,320. When multiplied by 60 (number of minutes in each hour) we get 25,920 again.
– 25,920 when divided by 432 equals 60, the same number we use seconds per minute and minutes per hour.
– 432 divided in half gives 216, a number similar to the 2,160 miles of the moon’s diameter. The number 432 when doubled gives 864, similar to the 864,000 miles of the sun’s diameter.
– The speed of light is 186,000 miles per second. The number 432 * 432 = 186,624.
Perhaps these are all coincidences. LOL!
It is, like everybody else says, a coincidence. Another solar system coincidence is Saturn´s rings, or at least them existing right now. They might be a short-lived (by astronomical scales phenomena). Two really cool coincidental things in our solar system.
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