Life in the Universe

Nobel Laureate Christian de Duve has argued that life is a cosmic imperative - at least from a chemist’s point of view. Can such a claim be substantiated? NASA’s “Origins” and “Astrobiology” Programs and programs of the European Space Agency (ESA) are actively seeking to return to Mars and, further, to explore Jupiter’s moons (Europa, Titan, Calisto) looking for life. Finding a second genesis of life in our solar system would greatly strengthen the arguments for the ubiquity of life in the universe.

Life is a planetary phenomena. A starting point for the search for life beyond our solar system is to find extra-solar planets. There are various observational techniques currently in use with terrestrial telescopes that allow this search to take place from the ground. At the time of the Cosmic Questions Conference 19 extra-solar planets had been discovered, some in multi-planet systems. Today, the number is 58 and still counting. However, none of these planets appear to be Earth-like. “Earths” are hard to find.

NASA and the ESA are developing ambitious terrestrial planet-finding (TPF) programs. These programs are seeking to develop space-based observational capacity to be able to discern Earth-like planets in systems as much as 50 light-years away. Spectroscopy using the TPF systems will allow atmospheric chemists and biologists to use the relative amounts of carbon dioxide, water vapor, ozone and methane in a planet’s atmosphere to find whether it someday could, did, or even now does support life.

In relation to the search for extraterrestrial life, these programs are very exciting. But what about extraterrestrial intelligent life? The chemical assay may be successful. Biologically relevant gasses may be found but that observation will not tell whether it is from algae or alumni.

Contributed by: Dr. Jill Tarter and Jim Miller