Newly translated ancient tablets show that ancient Babylonian astronomers used unexpectedly advanced geometry to understand the planets.

The find, described on Thursday in the journal Science, reveals that Babylonians tracked Jupiter by calculating the areas of trapezoids they used to symbolize the planet’s motion across the sky. This geometrical trick rewrites the history books: The technique was thought to have originated in England more than a millennium later.

The study also fills in crucial gaps, says Niek Veldhuis of the University of California, Berkeley, who wasn’t involved with the study, since it “finally connects Babylonian mathematical astronomy with geometrical mathematics”—a missing link that has eluded scholars for more than a century.

Researchers have long known that the Babylonians, who lived in what