Galileos Contribution to Astronomy The Telescope Galileos Telescope

Galileo’s Contribution to Astronomy: The Telescope

Galileo’s Telescope § Galileo didn’t actually invent the telescope – Terrestrial version was invented in the Netherlands by spectacle makers (Hans Lippershey, Zacharias Janssen, and Jacob Metius) § He did, however, improve upon the design in 1609 § Also first to point toward the night sky (only his improvements made this possible) § “Telescope” (Greek for “far seeing”) was first coined by Greek mathematician to refer to Galileo’s device

Support for Heliocentric Model § Phases of Venus: – Because Galileo observed all phases of Venus, it must orbit the sun – Such an observation was impossible in the geocentric model of Aristotle or Ptolemy Venus photo credit: Doug Anderson, Shoestring Astronomy

Support for Heliocentric Model § Moons of Jupiter: – Galileo observed the 4 largest moons of Jupiter and traced their orbits around this gas giant – This provided proof that bodies orbited objects other than the Earth Jupiter photo credit: Doug Anderson, Shoestring Astronomy

Other Contributions: The Moon § Galileo first to report craters and mountains on the moon – Moon not perfect sphere like Aristotle claimed

Other Contributions: Saturn § First to observe rings of Saturn but was confused by their appearance and couldn’t explain them

Other Contributions: The Milky Way § Even small telescope allows one to distinguish individual stars out of ‘milky’ cloud

Other Contributions: Sunspots § Galileo was one of first in Europe to observe sunspots § Made detailed drawings § Argued sunspots were actually on sun and not satellites of the sun § Further evidence against Aristotle’s view that everything in the heavens was perfect