Ptolemy's system of astronomy held up until 1543, when this Polish astronomer went heliocentric
... back the development of modern astronomy from the time of Aristotle until the 
16th... [DOC] [TLE] Copernicus and Kepler [PAR] Ancient astronomers gave considerable thought to the structure of the ... until the 
period between 1500 and 1543 A.D., when Polish astronomer ... Three years 
later, Copernicus started the first serious work on his heliocentric system of the 
..... for Kepler because having the planets travel non-circular orbits went against 
his... [DOC] [TLE] Nicolaus Copernicus - Biography, Facts and Pictures [PAR] By publishing his evidence that Earth orbits the sun, Nicolaus Copernicus ... 
Copernicus the Astronomer & his Heliocentric Solar System ... Everything in 
astronomy could be up for grabs!