What did Galileo observe about the Moon that contradicted the accepted doctrine?
Answer
It had mountains, valleys, and craters.
Galileo's initial observations revealed that the Moon had mountains, valleys, and craters, appearing much like the Earth, which shattered the Aristotelian distinction between the corruptible sub-lunar world and the unchanging, perfect celestial realm.
Related Questions
What cosmological model ruled the world before the telescope?To whom is the invention of the telescope often attributed around 1608?What was the approximate maximum magnification Galileo achieved after refining the telescope design?What did Galileo observe about the Moon that contradicted the accepted doctrine?In which 1610 publication did Galileo chronicle his observations of bodies orbiting Jupiter?What significant observation provided powerful evidence against the geocentric model by showing objects that did not revolve around the Earth?What specific observation by Galileo demonstrated that Venus must orbit the Sun?What established distinction was shattered by the observation that the Moon resembled the Earth?Besides celestial bodies orbiting Jupiter, what other observation about the Sun itself indicated the heavens were dynamic?What did turning the telescope toward the Milky Way imply about the universe's scale?What methodological shift is considered the most enduring legacy of the telescope's introduction to science?