Here is a good article on the subject. In it two Catholics are debating geocentrism, Galileo, etc. Long but interesting:
http://socrates58.blogspot.co.at/2010/11/geocentrism-not-at-all-infallible-dogma.html
Point #2: The decrees against Galileo were from Roman Congregations, approved only in forma communi. They were not papal decrees and therefore, all the more, were not immune from error.
As I have already demonstrated, the 1616 and 1633 decrees concerning Galileo were not “papal decrees”. Period. They were issued by Roman congregations. A papal decree and a decree from a Roman congregation are two different things. No amount of cajoling can make one into the other. In fact, the Catholic Encyclopedia states that the 1633 decree “did not receive the pope’s signature”.
from the same article:
It is clear that the absurdity was the act of the Italian Inquisition, for the private and personal pleasure of the pope — who knew that the course he took could not convict him as pope — and not of the body which calls itself the Church.
also:
I have said only that the decrees of Roman congregations approved in forma communi do not and cannot bind the universal Church to an irreformable, infallible doctrine. This is obvious even to honest inquirers outside the Church (as cited by the CE).
The Church does not teach geocentrism as a matter of faith. She never has. On the contrary, she has given us the direct principle—taught by the great Doctors Augustine and Thomas—that on matters of scientific inquiry, on “how the heavens go”, we are free to pursue these matters and come to varying conclusions. THAT is the teaching of the Church, as has been demonstrated here.
anway, the point is the trial was a political hit job on Galileo. Apparently he had really pissed off the pope by calling him a simpleton in his previous publication.