Astronomy is written for astronomers

I can easily conceive, most Holy Father, that as soon as some people learn that in this book which I have written concerning the revolutions of the heavenly bodies, I ascribe certain motions to the Earth, they will cry out at once that I and my theory should be rejected.

In so many and such important ways, then, do the planets bear witness to the earth's mobility.

At rest, however, in the middle of everything is the sun.

For it is the duty of an astronomer to compose the history of the celestial motions through careful and expert study.

Moreover, since the sun remains stationary, whatever appears as a motion of the sun is really due rather to the motion of the earth.

Of all things visible, the highest is the heaven of the fixed stars.