Total solar eclipses, like the upcoming one on April 8, occur on reliable schedules that we can calculate far into the past. This information helps researchers date mysterious events from ancient history.

Astroarcheology — also called archeoastronomy — uses astronomical records to help date key moments or events in history. Of all astronomical phenomena, total solar eclipses are among the best measuring sticks because they are only visible at a certain time and place.

Total solar eclipses are rare enough that a given spot on Earth is only likely to see one every 375 years (on average). And when an eclipse does happen, it only appears as total to those who are along a narrow path on Earth.