What a wonderful question! The simple answer is that they relied on centuries of previous observations. Remember, even computers have to be programmed with the right data to produce future times of ...

Add Yahoo as a preferred source to see more of our stories on Google. A new study of the Dresden Codex uncovers how Maya astronomers predicted solar eclipses for centuries using simple math and ...

"Cosmic archaeologists" have discovered an iron-deficient second-generation star, which provides evidence of how ancient stars enriched their successors.

Peering into the past, we find that our ancestors held a surprisingly advanced understanding of the stars and constellations. Their knowledge, as revealed in ancient texts, often rivals our modern ...

Before telescopes, ancient Greek astronomers relied on naked-eye observations of the night sky to understand the universe around them. The meticulous star catalog belonging to one of the best of these ...

It's a new window into the first star explosions.

A rare star reveals how the Universe's first stars exploded, helping explain the Milky Way’s outer halo and its unusual chemistry.

More than a thousand years ago, astronomers from the Maya civilization developed one of the most sophisticated time-keeping systems in the ancient world—a system that could predict solar eclipses for ...