Six graduate students from UC Riverside’s Department of Earth Sciences were among more than 700 researchers reporting on NASA’s ongoing exploration of life in the universe at the biennial Astrobiology Science Conference held at the Chicago Hilton in June.
Bound by the theme “Habitability, Habitable Worlds, and Life,” the weeklong, international gathering, known as AbSciCon 2015 for short, featured topics ranging from microbiology and spectroscopy to biogeochemistry and atmospheric modeling, which are the expertise of the UCR students who attended.
“The diversity of scientific disciplines represented at AbSciCon is unlike any conference I’ve ever been to,” said UCR’s Dalton Hardisty, whose graduate research focuses on reconstructing the availability of oxygen in the shallowest portions of Earth’s ancient oceans beginning around 2.5 billion years ago, when all life on Earth was still microscopic and animals had not yet evolved.
Hardisty’s findings support a recent hypothesis that oxygen remained low for about a billion years longer than previously thought, creating environmental conditions that probably stifled life’s evolution but never snuffed it out entirely. Independent evidence of these low-oxygen conditions and their resulting environmental impact were also the subject of talks by UCR graduate students Stephanie Olson, Leanne Hancock, and Charlie Diamond.
As part of UCR’s newly funded “Alternative Earths” project led by their advisor, Timothy Lyons, these four students seek to describe what life and its environment looked like in its earliest stages on Earth, which opens up a wide range of possibilities for what life could look like on a habitable world beyond our solar system. So far 1,540 extrasolar planets, or exoplanets, have been discovered orbiting other stars in our galaxy, according to the Exoplanet Orbit Database. Whether any are habitable is still unknown.
“It’s exciting that you have the opportunity to step out of your comfort zone and learn about new fields but equally challenging as you work to relate your own research to scientists outside your discipline, all while working toward finding common ground within various fields of astrobiology,” Hardisty explained.
Astrobiology combines the work of astronomers, chemists, biologists, geologists and physicists—each with their own perspectives on origins and evolution of life on Earth and the possibility of life elsewhere in our solar system and beyond. For example, many scientists at AbSciCon showcased computer simulations of theoretical climates on known exoplanets to explore how those conditions might foster or prevent life. This work anticipates NASA’s planned 2018 launch of the James Webb Space Telescope, which will enable humanity to peer into the atmospheres some of these distant worlds for the first time.
Other Abscicon talks addressed molecular fossils, carbon isotopes, and other direct chemical fingerprints of life, like those that may reside in Martian rock samples to be collected during NASA’s Mars 2020 mission. UCR graduate students Carina Lee and Alex Zumberge, both advised by Gordon Love, presented research on these direct records of ancient life on Earth roughly 700 million years ago, when the first animals were beginning to evolve.
All six UCR graduate student speakers at AbSciCon were featured during a day-long session titled “Mission to Early Earth: Co-Evolving Archean and Proterozoic Oceans, Atmospheres, and Life.” Lyons co-hosted the session with Noah Planavsky of Yale University and Christopher Reinhard of the Georgia Institute of Technology (both alumni of Lyons’ research group) and Sanjoy Som of the Blue Marble Space Institute of Science.
Astrobiology-related research at UCR is currently conducted through a five-year “Alternative Earths” grant from the NASA Astrobiology Institute (NAI), a nationwide collaboration of scientists at several universities, labs and NASA centers. The UCR-based NAI team is led by Lyons and includes Love, Mary Droser, and Andrey Bekker, all in the Department of Earth Sciences, in addition to working groups at Yale University, Georgia Institute of Technology, Arizona State University, J. Craig Venter Institute in La Jolla, Calif., and Oregon Health and Sciences University in Portland.
