Total solar eclipses like the one crossing America today are beautiful, but they’re tragically fleeting. Totality, when the sun is completely covered by the moon, lasts just a few minutes. And the whole thing — from the start of the partial eclipse to the end — takes just a few hours. The experience is sublime, but it’ll leave you wanting.
Here’s the good news: Total solar eclipses happen somewhere in the world every 18 months or so. That’s how long it takes for the specific conditions that create eclipses (the phases of the moon, the distance of the moon to Earth, and the moon crossing the plane of Earth’s orbit) to line back up.
The very next one will be on July 2, 2019, stretching over a wide swath of the Southern Pacific before passing across Chile and Argentina.
So that’s why we know, for instance, that on January 27, in the year 2837, a total solar eclipse will pass over southern Mexico (will anyone be around to see it?).
There's some comfort in knowing that people 1,000 years from now can look up in wonderment at the same natural phenomenon we see today. Life on Earth may change, but the sun, moon, and sky will not.