Although the occurrence climaxed on Jan. 21 with a conjunction—close alignment—of Saturn and Mercury, the planetary parade ...

Dallas shows an orrery – a mechanical model of the solar system. Before the 17th century most people believed in a geocentric model of the solar system. Dallas explains the geocentric model and ...

In the annals of history, Nicholas Copernicus is celebrated as the groundbreaking astronomer who toppled the geocentric view and unveiled the heliocentric model, placing the sun at the center of our ...