OryCon 44

What interplanetary and interstellar mechanisms exist that could transport microbial or other lifeforms across our Solar System or between systems, and what are the limits to survivability for organisms hitching a ride from one planetary body to another? With recent identification of interstellar objects observed passing through our system, speculations about cross-fertilization between Earth and Mars, and the prospects for ancient Earth life biosignatures to be found on the Moon, it is fruitful to take a hard look at the destructive and protective factors that such space-going organisms and their traces will face. What can we really expect to find, and how do we rigorously investigate these intriguing possibilities?