The Search for Early Life on Earth and Mars

No one knows when life first emerged on planet Earth, nor if or when Mars ever supported life. We see numerous, unequivocal lines of evidence for life on Earth from some 3.5 billion years ago to the present day. But the further back in time we look, the more clues about our earliest ancestors are clouded by doubts, uncertainties and controversies.

Similarly, the search for life on Mars is challenging, risky and controversial. Because it is improbable that any fossils are preserved on Mars, researchers must study the chemistry of its rocks to gain insights into potential habitable environments there. Scientists can do this using the instrument payload of the Curiosity rover now operating on the surface of Mars.

About the speaker:
Roger E. Summons, Ph.D., is professor of geobiology in the department of Earth, atmospheric and planetary sciences at the Massachusetts Institute of Technology. His research group studies the co-evolution of Earth’s early life and environment, microbially dominated ecosystems, the structure and biosynthesis of membrane lipids, biological mass extinction events and the origins of fossil fuels.