Venus-Earth-Mars: Comparative Climatology and the Search for Life in the Solar System

Tuesday, October 15, 2020 at 7:00 pm CDT with Roger Launius via Webinar on Zoom

Join HAL5 as we welcome Roger Launius, Both Venus and Mars have captured the human imagination during the twentieth century as possible abodes of life. Venus had long enchanted humans and all the more so since astronomers had realized that it was shrouded in a mysterious cloak of clouds permanently hiding the surface from view. It was also the closest planet to Earth, and a near twin to this planet in terms of size, mass, and gravitation. These attributes brought myriad speculations about the nature of Venus and the possibility of life existing there in some form. Mars also harbored interest as a place where life might exist. In large part this was due to observations reported by some astronomers who presented arguments that Mars was populated by a highly evolved civilization that had built a large system of canals in order to survive the ecological collapse of the planet’s environment. All the Mariner spacecraft planning charts from the early 1960s, for example, depicted Martian canals exactly where astronomer Percival Lowell had drawn them at the turn of the century Accordingly, in the first half of the twentieth century a popular conception held that the Sun had gradually been cooling for millennia and that as it did so each planet in the Solar System had a turn as a haven for life of various types. While it was now Earth’s turn for life to exist, the theory suggested that Mars had once been habitable and that life on Venus was now just beginning to evolve. Beneath the clouds of the planet, the theory offered, was a warm, watery world and the possibility of aquatic and amphibious life. “It was reasoned that if the oceans of Venus still exist, then the Venusian clouds may be composed of water droplets;” noted JPL researchers in 1963, “if Venus were covered by water, it was suggested that it might be inhabited by Venusian equivalents of Earth’s Cambrian period of 500 million years ago, and the same steamy atmosphere could be a possibility” (Jet Propulsion Laboratory, Mariner: Mission to Venus (New York: McGraw-Hill, 1963), p. 5). A core element of this belief rested with the climatology of these two planets, as observed by astronomers, but these ideas were dashed during the space age as probes to these planets significantly altered perspectives on them. Missions to Venus and Mars, revealed strikingly different worlds. On Venus a high pressure atmosphere led to the “greenhouse theory” of climatology and on Mars we found a cratered landscape similar to the surface of the Moon rather than canals of water flowing. Even so, the exploration of these planets continued and while Venus as an abode of life ended the search for evidence of life on Mars, either present or past, remains the central theme in the exploration plan of NASA and other spacefaring nations. This presentation explores the evolution of thinking about the Venus and Mars, its comparison to Earth, and the ongoing search for life in the solar system.

About STC

Roger D. Launius was Associate Director for Collections and Curatorial Affairs at the Smithsonian Institution’s National Air and Space Museum in Washington, D.C., until 2017. He has also been a senior curator and Division Chair in Space History at NASM. Between 1990 and 2002 he served as chief historian of the National Aeronautics and Space Administration. A graduate of Graceland College in Lamoni, Iowa, he received his Ph.D. from Louisiana State University, Baton Rouge, in 1982. He has written or edited more than thirty books on aerospace history, most recently since 2010: Historical Analogs for the Stimulation of Space Commerce (NASA SP-2014-4554, 2014); Space Shuttle Legacy: How We Did It and What We Learned (AIAA, 2013); Exploring the Solar System: The History and Science of Planetary Probes (Palgrave Macmillan, 2013); Coming Home: Reentry and Recovery from Space (NASA SP -2011-593, 2012), which received the AIAA’s history manuscript prize; and Globalizing Polar Science: Reconsidering the International Polar and Geophysical Years (Palgrave Macmillan, 2010). He is a Fellow of the American Association for the Advancement of Science, the International Academy of Astronautics, the American Astronautical Society, and the Royal Aeronautical Society, as well as associate fellow of the AIAA. He also served as a consultant to the Columbia Accident Investigation Board in 2003 and presented the prestigious Harmon Memorial Lecture on the history of national security space policy at the United States Air Force Academy in 2006. He is frequently consulted by the electronic and print media for his views on space issues, and has been a guest commentator on National Public Radio and all the major television network news programs.

The event is free and open to the public.

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