Summary: Today on the Ask An Astronomer Podcast... 1) We answer a question from a reader about the gas giant planets, and why they're so much bigger than the inner rocky planets. 2) Dave K and Dave B discuss the unknown dark matter that fills one quarter of the entire universe, but what it is astronomers still don't know. 3) And we listen to what lightning storms on Saturn sound like.... ...today on the Ask An Astronomer Podcast. Today's podcast is written and produced by David Bernat, Carl Ferkinhoff, Ann Martin, Betsy Adams, Manoilis Papastergis, Laura Spitler, Dan Tamayo, and David Kornriech. You can ask us your own questions by emailing us at 'curious@astro.cornell.edu' (please put 'AAA Podcast' in the title) or leave us a message at our new telephone number: 1-ITHACA-0-SKY (1-484-222-0759).
