Nearly 400 years ago, Galileo looked at the Pleiades star cluster through his telescope and noticed that the seven or so ...

This colored version of a 19th-century engraving depicts ancient Greek astronomer Hipparchus using a sighting tool to measure the positions of the stars. Science historians don't know exactly how ...

Ancient Greek astronomers were the first to gather knowledge about space exploration. Richard Branson and Jeff Bezos could ...

Uranus, being dim and slow-moving, did not appear among these and was therefore excluded from the traditional geocentric cosmology, which placed Earth at the center, surrounded by the concentric ...

Writes the study’s author, “Both astronomers (Copernicus and Ibn al-Shatir) replaced Ptolemy’s equant with additional circular motions, achieving uniform motion without an artificial ...

It mentions the lunar model in which the Muslim astronomer uses epicycles to correct Ptolemy’s exaggerated lunar distance variations. “This is nearly identical to Copernicus’s lunar model in ...

By placing the sun at the center, Copernicus’s idea overturned the ideas devised by the second-century astronomer Ptolemy. In Ptolemy’s theory the sun and planets orbited the Earth, which was ...

IT is somewhat strange that in the article on Ptolemy in the “Penny Cyclopædia,” he is spoken of only as a geographer. His fame is undoubtedly built upon his two great works on astronomy and ...

About 200 years later, the Egyptian polymath and author of the famous astronomy book Almagest, Claudius Ptolemy, refined the order of stars within these six levels.