The Days (And Years) Of Our Lives Looking at the numbers above, you'll immediately notice that you are different ages on the different planets. This brings up the question of how we define the time intervals we measure. What is a day? What is a year? The earth is in motion.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2012 March 12 The Scale of the Universe - Interactive Flash Animation Credit & Copyright: Cary & Michael Huang