Tuesday, November 10, 2009

APOD: Scale of Earth-moon system and a Saturn-moon system



Earlier this semester, we studied the true scale of the Earth-moon system. It is tough to get a good photo of Earth and our moon together, but here is one of Saturn and one of its moons, Tethys, that little blip halfway out and below the rings. Click for full size view. Again, it is plain to see that a moon and its planet are very different sizes. Excellent.