The School of Earth and Atmospheric Sciences Presents Dr. Laurie Barge, Jet Propulsion Laboratory at CalTech

Searching for Signs of Life and its Origin on Other Planets

Is there life elsewhere in the solar system, and if so how can we find it? Although Earth provides a variety of examples of what biology can look like, examples of the critical steps between abiotic and biotic systems are lacking because the prevalence of life on our planet has erased its record of prebiotic conditions. The distinction between biotic and abiotic is still often unclear, since we are still learning about the limits of life, and also because abiotic chemistry can become more complex when devoid of biological influence. However, prebiotic chemistry may still be a current or formerly active process on other worlds with detected chemical gradients and organics, such as Enceladus, Ceres, or Mars.

In this talk I will discuss how astrobiologists approach the search for life on other planets, and describe some of the difficulties in distinguishing living and non-living systems. In particular, I will share some of our group’s lab work on simulating prebiotic chemical systems that aim to bridge the gap between geochemistry and biochemistry, and will discuss some of the challenges in characterizing such systems using mission-relevant instruments.