January 29, 30, 31, February 1, 2
February 27, 28, March 1, 2
http://skyandtelescope.com/observing/objects/moon/article_723_1.asp
They didn't need to go up there to see its structure. They knew about the rings from projecting pictures taken from Earth onto a sphere.
![Shocked 8O](./images/smilies/icon_eek.gif)