With successful launches of the hayabusa 2 and osiris-REX missions we anticipate samples of carbonaceous asteroids ryugu and bennu to be returned in 2020 and 2023, respectively. Here we propose…

This is a $814,996.38 grant awarded by the National Aeronautics and Space Administration (NASA) to the University of Arizona, a public research university in Tucson, Arizona. The grant is for atomic-scale analysis of samples returned from the Japan Aerospace Exploration Agency's Hayabusa mission and analysis of analog samples for the future Hayabusa 2 and OSIRIS-REx asteroid sample return missions. The research effort is focused on understanding the thermal and weathering history of the Itokawa asteroid samples, as well as the nature of primordial organics in carbonaceous chondrite analogs to the expected Ryugu and Bennu samples. The grant does not have a set-aside designation. The University of Arizona, which operates under the Arizona Board of Regents, has extensive experience providing scientific research and technical support to various federal agencies through contract awards and grants.

With successful launches of the hayabusa 2 and osiris-REX missions we anticipate samples of carbonaceous asteroids ryugu and bennu to be returned in 2020 and 2023, respectively. Here we propose atomic-scale in-situ measurements of samples returned from asteroid itokawa and carbonaceous analogs to asteroids ryugu and bennu. Our proposed work is crafted around our new stateof- the-art capabilities in microscopy and spectroscopy. The research effort is broken into two major themes, the first one aimed at understanding the thermal and weathering history of itokawa and the second aimed at understanding the nature of primordial organics in carbonaceous chondrites analogous to what we expect returned from hayabusa 2 and osiris-REX. The hayabusa mission successfully returned over 1,500 dust particles from the surface of the near-earth s-type asteroid itokawa. Many of the particles showed signs of space weathering in the form of amorphous surface rinds and nanophase FE-bearing particles. Analysis of the particles suggest that they are consistent with a petrologic type LL4-6 ordinary chondrite. In theme 1, we will characterize hayabusa particles using focused-ION-beam scanning-electron microscopy (FIB) and aberration-corrected transmission electron microscopy (TEM). Particles will be chemically and structurally mapped using energy-dispersive spectroscopy and electron backscattered diffraction in the FIB. Based on such information, we will select representative areas for detailed analysis with TEM. Regions of interest will be site specifically extracted and thinned to electron transparency and FIB sections will be analyzed for detailed crystal chemistry and structure. We will use such information to decipher the thermal origins and weathering history of the hayabusa material and further explore their relationship to ordinary chondrites. In theme 2, we will determine the origins of primordial organics as analogs for analysis of material returned from asteroids ryugu and bennu. In the past decade, the cosmochemistry community has just begun to understand the origins and history of insoluble organic matter (IOM), the dominant organic component, in primitive carbonaceous chondrites. IOM exhibits isotopic anomalies (e.g., 15N and d excesses) whose magnitudes reach or even exceed those observed for interstellar molecules. We expect that hayabusa 2 and osiris-REX will indeed return primordial organics, but a full understanding of their nature will require detailed knowledge of and comparison to the organic inventory sampled by carbonaceous chondrites. We propose to identify and determine the nature of primordial organics, in situ, within carbonaceous chondrites, including their isotopic compositions and molecular functionality, as well as their possible relationship to other chondritic components. We will take advantage of our new capabilities in high-resolution imaging and spectroscopy provided by our NASA- and NSF-funded state-of-the-art TEM. We will develop analytical protocols for insitu study of meteoritic organics that will prepare US for similar measurements on samples to be returned by hayabusa 2 and osirisrex.