On March 24, 2009, Roger Launius, Senior Curator, Division of Space History, Smithsonian Institution's National Air and Space Museum spoke on the history of the search for life in the solar system.

He began his talk by comparing Venus and Mars with Earth. He informed us that people always thought there was life on Venus and Mars but not the other planets in the Solar System. Originally people thought Venus was shrouded by clouds, most likely of water vapor. Both planets were thought to be the planets most like Earth. Venus is even approximately the same size as Earth. The discoveries of the space age disproved those ideas.

In the past people thought the Sun had been cooling for millions of years. They thought Venus was a warm, watery planet. Carl Sagan was the first person to propose the idea that Venus had a runaway greenhouse effect. At present people think Venus has traces of water in the atmosphere.

Next Launius discussed the lure of the Mars, the Red Planet. Back in the 19^th Century there were science fiction stories that populated Mars with advanced civilizations. The astronomers Schiaparelli and Lowell thought they saw canals on the surface of Mars. People advanced the idea that Mars had a highly centralized, hydraulic society because of the need to move water around a mostly dry planet.

In 1965 Mariner 4 showed an alien, Moon like Mars covered with craters. Vikings 1 and 2 looked for life on Mars. Failure to find life sparked disappointment. Some enthusiasts thought they saw a “Face on Mars” after examining some imagery. More recent photography of the same feature discredited that idea.

A Martian meteorite discovered in Antarctica in 1996 suggested microorganisms on Mars millions of years ago. More recent research discounted that idea.

Launius discussed why people thought the way they have regarding life in the Solar System and, indeed, in the universe. He used the tag line from The X Files “I want to believe” to begin the conclusion to his talk. He mentioned the phenomenon of cognitive dissonance. In the past some religiously oriented millenialists thought the world would soon be coming to an end. When the date the world was supposedly to end came and went, people did not completely abandon their original belief but instead altered the date of the end of the world. Something similar has been happening regarding the belief in life on other planets. First most people abandoned the idea of civilizations on Mars and Venus, but not of life. But when further research further discredited the idea of life on Mars, people did not abandon their ideas completely.

More Photos of the Lecture