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Dean’s Lecture Fall 2023 — They contain depths: What Midwestern lakes tell us about early Earth and Mars

Author: lskramer | Image: lskramer

In her research, Swanner investigates Midwestern lakes that share common features with ancient Martian lakes and Earth’s past oceans. In her lecture, she will discuss how minerals form in lakes and what their presence in ancient Earth sediments or old Martian lakebeds can tell us about past microbial life on Earth or the possibility of life on Mars.

NASA’s Curiosity and Perseverance rovers are exploring some of these dried lakebeds on Mars, remnants of a wetter climate that existed about 3 billion years ago. The ancient Martian atmosphere contained little to no oxygen, as it does now, and the lake waters were enriched with iron – similar to Earth and its oceans 3 billion years ago.

Clues about the environments within these ancient waters lie in the sediments they left behind.  To be able to interpret the clues, scientists need to investigate the chemistry and mineral formation in water bodies that have little oxygen and are enriched with iron. This environment can be found in the special type of lake that Swanner explores. The lakes do not undergo seasonal mixing and maintain oxygen-free deep waters. With no oxygen, microbes are the dominant life form and their metabolisms can influence water chemistry and mineral composition.

Swanner became interested in microbes during her time as a biochemistry major at Mount Holyoke College, South Hadley, Massachusetts. Despite completing pre-med requirements, she decided to pursue her interests in microbiology and environmental sciences. After college, she worked as a river guide before starting her Ph.D. in geological sciences at the University of Colorado, Boulder. As a doctoral student, she gained expertise in geomicrobiology and aqueous geochemistry.

Swanner joined Iowa State in 2015 following a National Science Foundation (NSF)-funded postdoctoral post at the University of Tübingen in Germany. Her work is currently funded by an NSF CAREER award, as well as other grants from the NSF and NASA.

A live Q&A session with Swanner will follow the lecture.

This event is free and open to the public.

The Lecture extra credit link is

The LAS Dean’s Lecture highlights faculty excellence in learning, discovery and engagement. Each semester, the dean invites LAS faculty of distinction to present lectures from their own areas of expertise on topics of interest to the general public, designed to stimulate high-quality, intellectual discussion among faculty, staff, students and community members.

Or watch on YouTube.