April 21, 2018

Dr. Christine Floss died unexpectedly at her home in St. Louis on April 19, 2018, at age 56. She is deeply missed by her family, friends, and colleagues. Christine was a research professor in the Department of Physics and McDonnell Center for Space Sciences at Washington University in St. Louis. Christine was a long-time member and a fellow of the Meteoritical Society. She was an expert in the trace-element and isotopic analysis of planetary materials, meteorites, and presolar grains, studying the origin and evolution of the Solar System. She was a gifted and dedicated scientist and mentor, and an extraordinary colleague, collaborator, and friend to many in the cosmochemistry and planetary science community.

Christine’s research interests spanned a wide variety of extraterrestrial materials, from lunar samples to meteorites to presolar grains to returned samples from the NASA Stardust and Genesis missions to Antarctic micrometeorites to interplanetary dust particles. She played an important role in the chemical and isotopic studies of interplanetary dust particles, micrometeorites, and primitive chondrites to understand the origins and abundances of presolar and protosolar components in these materials. She performed isotopic and compositional studies of residues from Stardust craters and hypervelocity impact experiments to characterize the samples returned from comet 81P/Wild 2. Identification and characterization of craters from the Stardust interstellar dust collector was also part of her scientific work. She played a leading role in trace element distribution studies of individual minerals in extraterrestrial samples, to understand their petrogenesis as well as secondary effects occurring on their parent bodies (thermal metamorphism, aqueous alteration).

Christine earned a BA in German from Purdue University in 1983, a second degree in Geology from Indiana University, Bloomington in 1987, and a PhD in Geochemistry from the Department of Earth and Planetary Sciences at Washington University in St. Louis in 1991. Her dissertation focused on rare earth element distributions in meteorites (e.g., Aubrites) and ferroan anorthosites, working with Ghislaine Crozaz. She showed that the heterogeneous rare earth element patterns in oldhamite from aubrites reflect condensation from the solar nebula, rather than igneous processes in a parent body, as was believed at that time. It was during her time at Washington University that she developed her expertise with—and love of—the ion microprobe as her instrument of choice to explore the characteristics and origins of extraterrestrial materials.

Christine moved to Heidelberg, Germany, in 1991 for a research scientist position at the Max-Planck-Institut für Kernphysik. In 1993, while in Heidelberg, she married Frank Stadermann. While at the Max-Planck-Institut, she published on aubrites, angrites, pallasites, showing early-on the breadth of her interests. She was also involved with trace element studies of lunar samples (returning often to ferroan anorthosites), eucrites, lodranites, and acapulcoites.

 In 1996, Christine and Frank were invited to return to Washington University to work with their former advisors, Robert Walker and Ghislaine Crozaz. Christine joined the Laboratory for Space Sciences, now a part of the McDonnell Center for the Space Sciences, as a research scientist, and through the ensuing years, worked her way to become a full research professor. Christine worked with numerous colleagues, doing careful ion microprobe work that was essential in many studies. Along with Frank Stadermann, Ernst Zinner, and other coworkers, she developed unique expertise with the first Cameca NanoSIMS 50 instrument. Christine had over 250 coauthors and over 100 publications in peer-reviewed journals, and she led numerous research projects as principal investigator. In 2006, main-belt asteroid 6689 was named asteroid Floss.

In addition to her prolific research career, Christine played an active role in the cosmochemistry community. She was a member of the ANSMET (The Antarctic Search for Meteorites) team in 2014–2015, a reflection of her adventurous spirit. She served the scientific community in many ways, as a member of the Antarctic Meteorite Working Group, CAPTEM (The Curation and Analysis Planning Team for Extraterrestrial Materials), LPSC program committee, various student and early career awards committees, the Council of the Meteoritical Society, and much service on NASA review panels. She also served as the associate editor for Meteoritics and Planetary Science from 2005–2015. All of these activities reflected Christine’s personality and character; she was selfless, serious, level headed, balanced and fair, always positive and never complaining, a consummate professional.

At Washington University, Christine had a special role. Following in the giant footsteps of the likes of Robert Walker, Ernst Zinner, and Thomas Bernatowicz, Christine took on the role of lead scientist for the NanoSIMS and Auger Electron Microprobe laboratories, and served as mentor extraordinaire to a new generation of cosmochemistry students and analysts. She was a wonderful advisor to both undergraduate and PhD students; she always took the time to support all her students whenever they needed help, whether it was work-related or personal. In 2015, she was honored with a Washington University Outstanding Faculty Mentor award. All of her graduate students received NASA Earth and Space Science Fellowships for their research, which further attests to her excellent mentoring. She carried on a great tradition of the McDonnell Center for the Space Sciences at Washington University in training and mentoring students who have become strong contributors in the field of space science and who will certainly carry on in the same spirit of scientific curiosity and excellence as she did.

Christine is survived by her parents, Heinz G. Floss and Inge Floss; three siblings, Peter (and Barbara) Floss, Helmut Floss and Hanna Floss (and Tony Andrews); three children, Alisha, Erin (and Jeff) Hillam, Ashley Heavilon, and Amanda Stadermann, and three grandchildren (Minnie, Ezra, and Ruby Hillam).

Christine, you left us too soon; you will be sorely missed but dearly remembered.

—Brad Jolliff, Maitrayee Bose and Pierre Haenecour 

Categories: In Memoriam