ENCORE It’s one of the most bizarre biological experiments ever. In the 18th century, a scientist fitted a pair of tailor-made briefs on a male frog to determine the animal’s contribution to reproduction. The process of gestation was a mystery and scientists had some odd-ball theories. Today, a 5th grader can tell you how babies are made, but we still don’t know exactly what life is. In our quest to understand, we’re still at the frogs’ pants stage.Find out why conception took centuries to figure out. Also, why the 1970s Viking experiments, specifically designed to detect life on Mars, couldn’t give us a definitive answer. Plus, can knowing where life isn’t help define what it is? Take a tour of the world’s barren places. Guests: Jay Gallentine - Author of books about space and space history. Edward Dolnick - Author and former science writer at the Boston Globe. His book is The Seeds of Life: From Aristotle to Da Vinci, from Shark’s Teeth to Frogs’ Pants. Chris McKay - Planetary scientist, NASA Ames Research Center.  Learn more about your ad choices. Visit megaphone.fm/adchoices