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Universe theory
Greek astronomer Ptolemy develops geocentric theory of the universe with Earth at the center. -
Mar 24, 1050
mayan pyramid
Mayan Pyramid of Kukulkan at chichen itza is also used as calandar -
Apr 30, 1054
Supernova
Chinese astronomers observe supernova in Taurus -
Apr 30, 1259
astronomical observatory
First astronomer Nasir al-Din al-Tusi builds Iran's first astronomical observatory -
Apr 30, 1420
Samarkand
Astronomer Ulugh Beg builds atronomical observatory in Samarkand, central Asia -
Apr 30, 1543
heliocentric theory
Polish astronomer Nicolaus Copernieus publishes his heliocentric theory of the universe. -
Apr 30, 1572
supernova in constellaton
danish astronomer tycho brahe discovers a supernova in constellation of Cassiopeia -
Apr 30, 1582
Gregorian calendar
Pope Gregory 13 introduces the Gregorian calendar -
Germany
Kepler's first and second law were annonced -
use of constellations
Pacific islanders use constellations to travel across the Pacific Ocean