Astronomers of the times

Claudius Ptolemy was born

Claudius Ptolemy died

Claudius Ptolemy created the idea of Heliocenterism

Nicolaus Copernicus was born

Nicolaus Copernicus published a detailed astronomical manuscript on heliocenterism

Nicolaus Copernicus died

Nicolaus Copernicus elected cannon of a cathedral

Galileo Galilei was born

Galileo published his Letters on Sunspots, based on his observations of the dark spots on the Sun that are caused by intense magnetic activity

Galileo heard about a Dutch device for making distant objects look nearer. In about a month, Galileo Galilei invented the first telescope