What key phenomenon did Galileo observe regarding the planet Venus?
Answer
Venus exhibited a full cycle of phases.
Galileo observed that Venus went through a complete set of phases—new, crescent, gibbous, and full—similar to the phases seen on the Moon.
Related Questions
What fundamental scientific methodology did Galileo champion?What was the approximate maximum magnification Galileo achieved with his improved telescopes?What did Galileo document about the surface of the Moon?What philosophical division did the observation of an imperfect Moon help dissolve?What celestial bodies did Galileo observe orbiting Jupiter in early 1610?What name did Galileo initially give to the moons orbiting Jupiter?What key phenomenon did Galileo observe regarding the planet Venus?Why did observing a fully illuminated Venus contradict the Ptolemaic system?What Aristotelian concept regarding motion did Galileo's work challenge?According to Galileo, what language is the book of nature written in?What was the title of Galileo's work that brought him into direct conflict with the Catholic Church?