We all think of ourselves as Earthlings, but what if that wasn’t really the case? Our planet has been hit by meteorites that have originated from the moon and even Mars. What if one of these objects carried the seeds of life on Earth? Planetary scientist Steven Squyres describes this controversial process of “panspermia,” and what implications it carries for finding life on other planets.

Note: We apologize for the intermittent audio problems that are a product of the original recording of this program and not representative of typical WSF productions. Recorded June 2010; Posted April 2011