Observations, Meteorites, and Models: A Preflight Assessment of the Composition and Formation of (16) Psyche
Name
2019JE006296.pdf
Description
Published version
Size
4.19 MB
Format
Adobe PDF
Checksum (MD5)
a13434e122cd6c9eb5df6bb2610e9ba0
Author(s)
Elkins-Tanton, LT
Asphaug, E
Bell, JF
Bercovici, H
Bills, B
Binzel, R
Bottke, WF
Dibb, S
Lawrence, DJ
Marchi, S
Date Issued
2020
Journal
Journal of Geophysical Research: Planets
Publisher
American Geophysical Union (AGU)
Version
Final published version
Abstract
© 2020. The Authors. Some years ago, the consensus was that asteroid (16) Psyche was almost entirely metal. New data on density, radar properties, and spectral signatures indicate that the asteroid is something perhaps even more enigmatic: a mixed metal and silicate world. Here we combine observations of Psyche with data from meteorites and models for planetesimal formation to produce the best current hypotheses for Psyche's properties and provenance. Psyche's bulk density appears to be between 3,400 and 4,100 kg m−3. Psyche is thus predicted to have between ~30 and ~60 vol% metal, with the remainder likely low-iron silicate rock and not more than ~20% porosity. Though their density is similar, mesosiderites are an unlikely analog to bulk Psyche because mesosiderites have far more iron-rich silicates than Psyche appears to have. CB chondrites match both Psyche's density and spectral properties, as can some pallasites, although typical pallasitic olivine contains too much iron to be consistent with the reflectance spectra. Final answers, as well as resolution of contradictions in the data set of Psyche physical properties, for example, the thermal inertia measurements, may not be resolved until the NASA Psyche mission arrives in orbit at the asteroid. Despite the range of compositions and formation processes for Psyche allowed by the current data, the science payload of the Psyche mission (magnetometers, multispectral imagers, neutron spectrometer, and a gamma-ray spectrometer) will produce data sets that distinguish among the models.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution NonCommercial License 4.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2019JE006296
