Henri Sack Memorial Lecture: Rhonda Stroud (Arizona State)

Asteroid Goo, Moon Water, and the Frontiers of Astromaterials Microscopy

Astromataerials microscopy can address big picture questions such as, “Where did the ingredients for life on Earth form?” and “Are there technologically important materials on the Moon or asteroids?” Terrestrially collected samples from space, including stratospherically collected interplanetary dust particles and more than 75,000 named meteorites, provide materials from asteroids, comets, and even stars older than the Sun, for laboratory study. Returned samples from spacecraft missions that target specific bodies, such as the recent JAXA Hayabusa2 mission to the carbonaceous asteroid Ryugu and the historic NASA Apollo lunar missions of the 1960s and early ‘70s, often provide the greatest scientific value. For example, Hayabusa2 sample analyses recently showed C-type asteroids to be genetically related to carbonaceous chondrite meteorites, and thus the major source of organic carbon and water to the surface of the early Earth. Lunar soil samples, stored since their return in 1972, have shown evidence for mineral-phase dependent retention of implanted H and He, which could change our understanding of the lunar exosphere and the potential availability of lunar resources for in situ utilization. Future sample-return from Mars, Martian moons or other small bodies might reveal signatures of life beyond Earth. All of these studies benefit from on-going technological advances in ground-based analytical instrumentation.

Bio:
Rhonda Stroud joined Arizona State University in 2022 as the director of the Buseck Center for Meteorite Studies. Her current research focuses on laboratory analyses of astromaterials to determine how materials in the Solar System have formed and evolved from the initial formation of the nebula to modern day. She is recognized for her leadership in the application of electron microscopy and focused ion beam methods to the study of presolar stardust, and returned comet, asteroid, and interstellar dust samples. Asteroid 8468Rhondastroud is named in her honor by the International Astronomical Union.

She received her doctorate in physics from Washington University in St. Louis in 1996 for research on the phase stability of TiZrNi quasicrystals and subsequently joined the Naval Research Laboratory (NRL) as an NRC Postdoctoral Fellow to study the effects of atomic disorder on colossal magnetoresistive oxides. She became a Research Physicist at NRL in 1998, serving as Head of the Nanoscale Materials Section of the Materials Science and Technology Division from 2007-2022. Her NRL research portfolio combined ONR funded microscopy of novel materials for optical, electronic and energy applications with NASA-sponsored research on meteorites and returned samples.

Stroud has served in several leadership and subject matter expert roles for NASA, DOE, DoD, the National Academies, and is a Fellow of the American Physical Society, the Meteoritical Society, the Microscopy Society of America and the Microanalysis Society. She was a member of the Small Bodies committee of the 2023-2032 NASA Planetary Science Decadal Survey, a member of the NASA Planetary Science Advisory Committee (2018-2020), and the President of the Microanalysis Society (2018-2020).