PHY 104 Tuesday, January 29, 2008 PLANETARY MOTION andGRAVITY.
Galaxies. Galaxies A galaxy is a huge region of space that contains hundreds of billions of stars, planets, glowing nebulae, dust, empty space, and possibly.
Astro 201: Sept. 2, 2010 Do on-line practice quiz #2 (see d2l) Homework #2: posted on web page after class Today: – Ancient Greeks – Ptolemy V. Copernicus;
Galaxies