Galaxies!

Activities:
http://amazing-space.stsci.edu/eds/overviews/explorations/hunter.php.p=Teaching+tools%40%2Ceds%2Ctools%2C%3EGalaxies%40%2Ceds%2Ctools%2Ctopic%2Cgalaxies.php
http://amazing-space.stsci.edu/eds/overviews/explorations/galore.php.p=Teaching+tools%40%2Ceds%2Ctools%2C%3EGalaxies%40%2Ceds%2Ctools%2Ctopic%2Cgalaxies.php
http://amazing-space.stsci.edu/resources/explorations/hdf/
http://btc.montana.edu/CERES/html/Galaxy/gal1.html
http://hou.lbl.gov/ISE/new/galaxy/galaxy2.html
http://www.galaxygames.org/