• DOI:10.3847/PSJ/abfdba
• Corpus ID: 235918955

Asteroid 16 Psyche: Shape, Features, and Global Map

@article{Shepard2021Asteroid1P,
  title={Asteroid 16 Psyche: Shape, Features, and Global Map},
  author={Michael K. Shepard and Katherine de Kleer and Saverio Cambioni and Patrick A. Taylor and Anne K. Virkki and Edgard G. R{\'i}vera-Valentin and Carolina Rodriguez S{\'a}nchez-Vahamonde and Luisa Fernanda Zambrano-Marin and Christopher Magri and David Dunham and John Moore and Maria Camarca},
  journal={The Planetary Science Journal},
  year={2021},
  volume={2}
}

• M. Shepard, Katherine de Kleer, +9 authors M. Camarca
• Published 7 October 2021
• Physics, Geology
• The Planetary Science Journal

We develop a shape model of asteroid 16 Psyche using observations acquired in a wide range of wavelengths: Arecibo S-band delay-Doppler imaging, Atacama Large Millimeter Array (ALMA) plane-of-sky imaging, adaptive optics (AO) images from Keck and the Very Large Telescope (VLT), and a recent stellar occultation. Our shape model has dimensions 278 (−4/+8 km) × 238(−4/+6 km) × 171 km (−1/+5 km), an effective spherical diameter D eff = 222-1/+4 km, and a spin axis (ecliptic lon, lat) of (36°, −8°) ± 2°. We survey all the features previously reported to exist, tentatively identify several new features, and produce a global map of Psyche. Using 30 calibrated radar echoes, we find Psyche’s overall radar albedo to be 0.34 ± 0.08 suggesting that the upper meter of regolith has a significant metal (i.e., Fe–Ni) content. We find four regions of enhanced or complex radar albedo, one of which correlates well with a previously identified feature on Psyche, and all of which appear to correlate with patches of relatively high optical albedo. Based on these findings, we cannot rule out a model of Psyche as a remnant core, but our preferred interpretation is that Psyche is a differentiated world with a regolith composition analogous to enstatite or CH/CB chondrites and peppered with localized regions of high metal concentrations. The most credible formation mechanism for these regions is ferrovolcanism as proposed by Johnson et al. (2020).