Asteroid (16) Psyche: Evidence for a silicate regolith from spitzer space telescope spectroscopy
| Autor: | Joshua P. Emery, Humberto Campins, Zoe A. Landsman, Dale P. Cruikshank, Josef Hanus, Lucy F. Lim |
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| Rok vydání: | 2018 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Regolith Silicate Psyche chemistry.chemical_compound Spitzer Space Telescope Meteorite chemistry Space and Planetary Science Asteroid 0103 physical sciences Emissivity Protoplanet 010303 astronomy & astrophysics 0105 earth and related environmental sciences |
| Zdroj: | Icarus. 304:58-73 |
| ISSN: | 0019-1035 |
| Popis: | Asteroid (16) Psyche is a unique, metal-rich object belonging to the “M” taxonomic class. It may be a remnant protoplanet that has been stripped of most silicates by a hit-and-run collision. Because Psyche offers insight into the planetary formation process, it is the target of NASA’s Psyche mission, set to launch in 2023. In order to constrain Psyche’s surface properties, we have carried out a mid-infrared (5–14 µm) spectroscopic study using data collected with the Spitzer Space Telescope’s Infrared Spectrograph. Our study includes two observations covering different rotational phases. Using thermophysical modeling, we find that Psyche’s surface is smooth and likely has a thermal inertia Γ = 5–25 J/m2/K/s1/2 and bolometric emissivity ϵ = 0.9, although a scenario with ϵ = 0.7 and thermal inertia up to 95 J/m2/K/s1/2 is possible if Psyche is somewhat larger than previously determined. The smooth surface is consistent with the presence of a metallic bedrock, which would be more ductile than silicate bedrock, and thus may not readily form boulders upon impact events. From comparisons with laboratory spectra of silicate and meteorite powders, Psyche’s 7–14 µm emissivity spectrum is consistent with the presence of fine-grained ( |
| Databáze: | OpenAIRE |
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