I attended Worldcon, the World Science Fiction Convention, in Spokane last summer.  The event was kicked off by a spectacular talk by astronomer Brother Guy Consolmagno, winner of the Carl Sagan Medal for excellence in public communication of planetary science.  I'm looking forward to the science & science fiction panels at Worldcon in Kansas City (MidAmeriCon II) this August.  In the meantime, I rummaged the web and found a recording of Brother Guy's talk "Discarded Worlds: Astronomical ideas that were almost correct."  The recording is not from Spokane, but from his visit to IHMC in Florida.  Enjoy.