How to Find a Habitable Planet

Presenter: James Kasting, Pennsylvania State University
When: December 10, 2010 9AM PST

Over 400 planets have been found around nearby stars, but none of them is thought to be at all like Earth. The goal now is to identify rocky planets within the habitable zones of their stars and to search their atmospheres spectroscopically for signs of life. To do this, we need new space-based telescopes such as NASA’s proposed Terrestrial Planet Finders or ESA’s Darwin mission (all of which are indefinitely postponed at the moment). If spectra of extrasolar planet atmospheres can be obtained, the presence of O2, which is produced from photosynthesis, or O3, which is produced photochemically from O2, would under most circumstances provide strong evidence for life beyond Earth. But “false positives” for life may also exist, and these need to be clearly delineated in advance of such missions, if at all possible. I will also contrast my optimism about the search for complex life with the more pessimistic view expressed by Ward and Brownlee in their book, Rare Earth.

Space Telescope Science Institute Webcast Series

  • Johns Hopkins University and the Space Telescope Science Institute present live and on-demand webcasts related to science, technology, and business to the scientific community and the public at-large. Live webcasts, production services, and the webcast archive are managed by the Information Technology Services division of the Space Telescope Science Institute.
  • Subscribe to this series