Inner and outer planets
Monday, April 13th, 2009
Earth is percieved as a rocky planet, what are other planets like? Did you know Mars is cold and that outer planets are really gigantic gas envelopes? What about a liquid planet? Could such a planet exist? And what really defines a planet, anyway? Explore these questions and more on this week's "SkyTalk."
Visit the Skytalk web page for more information.