15. Questions to think about What are all the phases? How long does it take for all the phases to happen? What makes the moon visible to us?
16. Citations Irargerich, “Big Full Moon”, April 21, 2008 via Flickr, Creative Commons License. Minds-eye, “Crescent Moon 7-26-09”, July 26, 2009 via Flickr, Creative Commons License. Dcysurfer, “First quarter luna (with Apollo landing sites)”, February 3, 2009 via Flickr, Creative Commons License.