Rachel
About
Khan Academy on a Stick
Scale of the Galaxy
Scale of the Galaxy
Scale of earth, sun, galaxy and universe
Scale of Earth and Sun
Scale of Solar System
Scale of Distance to Closest Stars
Scale of the Galaxy
Intergalactic Scale
Hubble Image of Galaxies
Your browser does not support video. Please get the latest version of Google Chrome, Firefox, IE, or Safari. Alternately, you can try the link below if you have VLC or another media player installed.
If the above player doesn't work, you can
try this direct link
.