We current JWST/NIRSpec observations of the 5 Jupiter Trojans that might be visited by the Lucy spacecraft — the Patroclus–Menoetius binary, Eurybates, Orus, Leucus, and Polymele.
The measured 1.7-5.3 μm reflectance spectra vastly supersede earlier ground-based spectroscopy in spectral decision, signal-to-noise ratio, and wavelength protection and reveal a number of distinct absorption options.
We robustly detect a broad OH band centered at 3 μm that’s most outstanding on the less-red objects Eurybates, Patroclus-Menoetius, and Polymele. An extra absorption at 3.3-3.6 μm, indicative of aliphatic organics, is systematically deeper on the crimson objects Orus and Leucus. The collisional fragment Eurybates is exclusive in displaying an absorption band at 4.25 μm that we attribute to certain or trapped CO2 (e.g., clathrates).
Comparisons with different photo voltaic system small our bodies reveal broad similarities within the 2.7-3.6 μm bands on the Trojans with analogous options on Centaurs, Kuiper belt objects, and the lively asteroid 238P. Within the context of current photo voltaic system evolution fashions, which posit that the Trojans initially fashioned within the outer Photo voltaic System, the numerous attenuation of the two.7-3.6 μm absorptions on Trojans relative to Kuiper belt objects could also be the results of secondary thermal processing of the Trojans’ surfaces on the increased temperatures of the Jupiter area.
The CO2 band manifested on the youthful floor of Eurybates means that CO2 could also be a significant constituent within the bulk composition of Trojans, however resides within the subsurface or deeper inside and is basically obscured by refractory materials that fashioned from the thermophysical processes that have been activated throughout their inward migration.
Ian Wong, Michael E. Brown, Joshua P. Emery, Richard P. Binzel, William M. Grundy, Simone Marchi, Audrey C. Martin, Keith S. Noll, Jessica M. Sunshine
Feedback: Submitted to PSJ. 12 pages, 6 figures
Topics: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2311.11531 [astro-ph.EP] (or arXiv:2311.11531v1 [astro-ph.EP] for this model)
Submission historical past
From: Ian Wong
[v1] Mon, 20 Nov 2023 04:30:12 UTC (622 KB)