United States Commemorative Stamps, 500th Anniversary of the Birth of Nicolaus Copernicus, Polish Astronomer,
Copernican Theory Includes the Following Concepts:
Heavenly motions are uniform, eternal, and circular or composed of several circles (epicycles).
Near the Sun is center of the universe.
Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, and the fixed stars are around the Sun.
The Earth rotates, revolves around the sun yearly with a daily rotation, and tilts of its axis in its revolution.
Retrograde motion of the planets is explained by the Earth's motion.
The distance from the Earth to the sun is small compared to the distance to the stars.
Issued April 23, 1973 in Washington, DC,
First Day of Issue Cover, FDC, Art Craft Engraving Cachet, Unaddressed, Ideal for Framing,
Cover in Removable Transparent Poly Sleeve and Mailed With Protection,
Made in the USA
Genuine First Day of Stamp Issued Cover Cancelled on the First Day of Issue Date by the U.S. Postal Service,
