On this day in 1473 - February 19th - Nicolaus Copernicus was born.

His work De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) set out his arguments for a heliocentric (sun-centered) system instead of a geocentric (Earth-centered) system.


Mona Evans
For news, activities, pictures and more, sign up to the Astronomy Newsletter!

http://www.bellaonline.com/newsletter/astronomy