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 ...

Cleostratus was a truly pioneering Greek astronomer who lived on the small Aegean island of Tenedos in the 6th century BC.

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 ...

A class of undergraduate students at University of Chicago has used data from the Sloan Digital Sky Survey (SDSS) to discover ...

These halos, crucial to understanding galaxy formation, were largely unknown until the Hobby-Eberly Telescope Dark Energy ...

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 ...

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

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 ...