Dr. Elena Dobrica
Hydrothermal experiments, electron microscopy, cosmochemistry, dust particles, meteorites, returned samples
Ph.D., University Paris-Sud XI, 2010
dobrica@hawaii.edu
+1 808 956 5370
POST 526A

Overview

Projects:
I am broadly interested in the formation of the solar system and the evolution of primitive materials. The textural and mineralogical characteristics of fine-grained materials in chondrites (i.e., interchondrule matrix and fine-grained rims) and dust particles (i.e., interplanetary dust particles—IDPs and Antarctic micrometeorites—AMMs) can be used to constrain the physico-chemical conditions of grain formation in the solar nebula. In addition, these nanometer-sized materials are also sensitive to pre- and post-accretionary processes on the parent body such as thermal metamorphism, aqueous alteration, brecciation, or shock. To reconstruct the environment in which such natural nanomaterials formed and evolved, my research focuses on the characterization of their textures, mineralogy, and isotopic compositions at the micro- to nanoscales.

Comet and Asteroid return samples
I have been working on returned samples from the Jupiter-family comet 81P/Wild 2 (NASA-Stardust mission) and the S-type asteroid 25143 Itokawa (JAXA-Hayabusa mission). The analyses of these returned samples provide us the opportunity to overcome the constraints imposed by remote sensing. Future return sample missions, such as OSIRIS-REx and Hayabusa2, will collect particles from the upper part of the asteroidal regoliths (asteroid 101955 Bennu-OSIRIS-REx mission and asteroid 162173 Ryugu-Hayabusa2) that will give us information about: (1) surface modification processes on airless bodies such as solar wind ion implantation, sputtering, energetic particle irradiation, and micrometeoroid impacts; (2) mixing and transport of material within the protoplanetary disk; and (3) mineral-water-organic chemical reactions. The analyses of these future returned samples will enhance our knowledge of asteroids and of the dynamic history of the solar system.

Antarctic micrometeorites and interplanetary dust particles
Currently, I am investigating the source and formation of Antarctic micrometeorites (AMMs) and interplanetary dust particles (IDPs) using detailed descriptions of the mineralogy and isotopic compositions of secondary phases. My current research has important implications for understanding the mechanisms and formation times of secondary minerals in hydrated particles and can potentially distinguish between asteroidal and cometary alteration. Additionally, this project provides insights into the genetic relationship between anhydrous and hydrated IDPs and micrometeorites, the Stardust cometary samples, and carbonaceous chondrites.

Hydrothermal experiments
Additionally, my research brings together theoretical knowledge about the earliest stages of metamorphism and aqueous alteration in chondrites with hydrothermal alteration and fluid-assisted metamorphism experiments. I am performing hydrothermal alteration and fluid-assisted metamorphism experiments on amorphous silicate at different conditions to constrain the chemical reactions and the role of fluids during fluid-assisted parent body thermal metamorphism that has affected the matrices of unequilibrated ordinary and carbonaceous chondrites.

Mailing Address
Hawaiʻi Institute of Geophysics and Planetology
University of Hawaiʻi at Mānoa
1680 East-West Road, POST Building, Office 602
Honolulu, HI 96822
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