Dr. Cyrena A. Goodrich
Senior Staff Scientist
Dr. Cyrena Goodrich studies the petrology, geochemistry, and isotope geochemistry of meteorites and returned samples from asteroids in order to understand the early evolution of the solar system. Her current work is focused on unique carbonaceous chondrite meteorites and returned samples from the C-type asteroid Ryugu, which represent some of the most primitive materials in the solar system, as well as primitive achondrites, which represent asteroids that experienced the early stages of geologic processing.
Selected Current Research Projects:
Ryugu and the Quest for Unaltered CI-Like Material from the Early Solar System: Samples of C-type asteroid (162173) Ryugu returned by the Hayabusa2 mission of JAXA are mineralogically, chemically, and isotopically similar to the rare CI carbonaceous chondrite meteorites, which are of paramount importance because they are considered to represent the starting composition of the solar system. Paradoxically, however, all known CI have been altered by aqueous fluids on their parent asteroids so that their primary mineralogy, textures, and oxygen isotope compositions have been obscured. Thus, one of the most exciting discoveries from Ryugu samples is that they show “less-altered” areas, which contain unaltered minerals that are remnants of primordial CI. Dr. Goodrich and a team of meteorite petrologists, isotope geochemists, and spectroscopists, are studying these areas in Ryugu samples to aid in the quest for unaltered CI-like materials from the early solar system.
Asteroid 2008 TC3 and the Almahata Sitta Meteorite: The Almahata Sitta meteorite fell in 2008 when asteroid 2008 shattered over the desert of Northern Sudan. 2008 TC3 was the first Near-Earth Object to be detected before it impacted Earth, which made it a milestone in planetary protection. Almahata Sitta, a collection of >600 cm-sized stones of diverse types, is the first meteorite to be derived from an asteroid that had been tracked and studied in space before impact. Dr. Goodrich leads a multidisciplinary team of experts that include meteorite petrologists and geochemists, spectroscopists, meteor astronomers, and physicists to study the University of Khartoum (Sudan) collection of Almahata Sitta, which is curated by team member Professor Muawia Shaddad. They are using the analyzed properties of the stones, combined with pre-impact observations of the asteroid, to understand the composition, structure, fragmentation behavior, and origin of this asteroid.
Goodrich C.A., Downes H., Greenwood R., Ross A., Fioretti A.M., Alexander L., Kita N.T., Butler J., Jercinovic M.J., Jenniskens P. and Shaddad M.H. (2023) Enstatite meteorite clasts in Almahata Sitta and other polymict ureilites: Implications for the formation of asteroid 2008 TC3 and the history of enstatite meteorite parent asteroids. Meteoritics & Planetary Science, submitted.
Jenniskens P., Robertson D., Goodrich C.A., Shaddad M.H., Kudoda A., Fioretti A.M., and Zolensky M.E. (2022) Bolide fragmentation: What parts of asteroid 2008 TC3 survived to the ground?" Meteoritics & Planetary Sciences, 57,1641-1664.
Xenoliths in Meteoritic Breccias: Some meteorites are breccias (rocks that consist of broken fragments of other rocks welded together) that represent the regolith, or outermost layers,of an asteroid, where numerous impacts of other bodies caused shattering and extensive “gardening” of the debris. Some of the rock fragments in this debris include pieces of the impactors. Dr. Goodrich studies the mineralogy, petrology, and geochemical properties of these foreign fragments, known as xenoliths, to reveal chemical and isotopic properties of early solar system materials that may not be represented by known meteorite types. In addition, she uses these xenoliths to provide information on early solar system impacts and dynamical processes.
Goodrich C.A., Sanborn M.E., Yin Q-Z., Kohl I., Frank D., Daly R.T., Walsh K.J., Zolensky M.E., Young E.R.D., Jenniskens P. and Shaddad M.H. (2021) Cr Isotopic Evidence for Mixing of NC and CC Reservoirs in Polymict Ureilites: Implications for Early Solar System Dynamics. Planetary Science Journal, Volume 2, Issue 1, id.13, 15 pp.
Goodrich C.A., Kring D.K. and Greenwood R. (2021) Xenoliths in ordinary chondrites and ureilites: Implications for early solar system dynamics. Meteoritics & Planetary Sciences 56, 1949-1987.