Jupiter's four largest moons are known as the "Galilean moons", since it was he who first observed them, using his homemade telescope. Observing moons orbiting around another planet was contrary to the notion the Church held dear - that everything in the universe revolved around the Earth. Galileo discovered other new features, he found that the sun is not immaculate as was previously believed but has sunspots and discovered mountains on the moon. Galileo discovered that Venus has phases which was incompatible with the old Ptolemaic geocentric system. Johannes Kepler and Isaac Newton developed the theory further and provided the scientific underpinning which led to its universal acceptance. Kepler showed that the planets orbit the sun in ellipses rather than perfect circles as previous heliocentrists had thought.
 Religious persecution
"To assert that the earth revolves around the sun is just as erroneous as to claim that Jesus was not born of a virgin." - Cardinal Bellarmino
"The first proposition, that the sun is the centre and does not revolve about the earth, is foolish, absurd, false in theology, and heretical, because expressly contrary to Holy Scripture; and the second proposition, that the earth is not the centre but revolves about the sun, is absurd, false in philosophy, and heretical, because expressly contrary to Holy Scripture. The second proposition, that the earth is not the centre but revolves around the sun, is absurd, false in philosophy, and from a theological point of view at least, opposed to the true faith." - Judgment of the Inquisition
Galileo was forced to recant by the Catholic Inquisition, but famously was alleged to have muttered "E pur si muove" - "And yet, it moves". For his recantation, Galileo was not executed as a heretic, but instead sentenced to house arrest for the remainder of his life. Centuries later, the Catholic Church expressed regret for how the Galileo affair was handled, and officially accepted the theory of heliocentrism. Later scholarship has stated that, although the church did reject his arguments, it was over proving his findings, rather than the substance. His forced recanting was over accusations that he had insulted the Pope in his second work, in which he satirized the Pope as a character named "Simplicio," rather than over his theories themselves.
When invited to verify his findings by looking through his telescope, conservative Christians declined to do so. Some things never change.
I do not feel obliged to believe that the same God who has endowed us with senses, reason, and intellect has intended us to forgo their use and by some other means to give us knowledge which we can attain by them.
E pur si muove - "And yet, it moves"
 See also
- Galileo gambit
- Giordano Bruno
- Tycho Brahe
- Johannes Kepler
- Isaac Newton
 No relation
- ↑ Simon Marius claimed to have discovered these moons a few days earlier, which Galileo disputed. Though we call them the Galilean satellites, their names -- Io, Europa, Ganymede, and Callisto -- were Marius's idea. Galileo just called them Jupiter I, Jupiter II, Jupiter III, and Jupiter IV.
- ↑ There's no evidence that he ever said the phrase at all, and he would have been bloody stupid to have done so.
- ↑ The fact that he recanted the evidence apparently did not prevent him being punished for even considering it, which some might call thought crime.
- ↑ In 1992, just as galactocentrism was coming into vogue. Baby steps, baby steps.
- ↑ Sharratt, Michael. Galileo: Decisive Innovator. (Cambridge University Press, Cambridge, 1994)
- ↑ Pantin, Isabella. "New Philosophy and Old Prejudices: Aspects of the Reception of Copernicanism in a Divided Europe", Studies in History and Philosophy of Science Part A 30: 237–262