Ultraviolet Spectroscopy of Lucy Mission Targets with the Hubble Space Telescope

Humes, Oriel A.; Thomas, C. A.; Emery, Joshua P.; Grundy, W. M.

doi:10.3847/psj/ac8059

Cited by 2 publications

(1 citation statement)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A positive identification of a sulfur-bearing species on a Jovian Trojan or irregular satellite would provide intriguing context for the overall origins of these objects. However, UV observations of Trojans by Wong et al (2019) and Humes et al (2022) do not detect any absorption features associated with H 2 S or features related to the salts suggested by Yang et al (2013). We further note that our visible spectra of Sycorax and Caliban constrain the history of H 2 S in the ice giant region of the outer solar system, as their colder surfaces would more easily preserve the processed record of any sulfur-based chemistry similar to Poston et alʼs (2018) laboratory observations of absorption bands at 0.41, 0.62, and 0.90 μm.…”

Section: Hypotheses For the Spectral Variation Of Jovian Irregular Sa...mentioning

confidence: 99%

Spectroscopic Links among Giant Planet Irregular Satellites and Trojans

Sharkey,

Reddy,

Kuhn

et al. 2023

Planet. Sci. J.

View full text Add to dashboard Cite

We collect near-infrared spectra (∼0.75–2.55 μm) of four Jovian irregular satellites and visible spectra (∼0.32–1.00 μm) of two Jovian irregular satellites, two Uranian irregular satellites, and four Neptune Trojans. We find close similarities between the observed Jovian irregular satellites and previously characterized Jovian Trojans. However, irregular satellites’ unique collisional histories complicate comparisons to other groups. Laboratory study of CM and CI chondrites shows that grain size and regolith packing conditions strongly affect spectra of dark, carbonaceous materials. We hypothesize that different activity histories of these objects, which may have originally contained volatile ices that subsequently sublimated, could cause differences in regolith grain size or packing properties and therefore drive spectral variation. The Uranian satellites Sycorax and Caliban appear similar to TNOs. However, we detect a feature near 0.7 μm on Sycorax, suggesting the presence of hydrated materials. While the sample of Neptune Trojans have more neutral spectra than the Uranian satellites we observe, they remain consistent with the broad color distribution of the Kuiper Belt. We detect a possible feature near 0.65–0.70 μm on Neptune Trojan 2006 RJ103, suggesting that hydrated material may also be present in this population. Characterizing hydrated materials in the outer solar system may provide critical context regarding the origins of hydrated CI and CM chondrite meteorites. We discuss how the hydration state(s) of the irregular satellites constrains the thermal histories of the interiors of their parent bodies, which may have formed among the primordial Kuiper Belt.

show abstract

Section: Hypotheses For the Spectral Variation Of Jovian Irregular Sa...mentioning

confidence: 99%

Spectroscopic Links among Giant Planet Irregular Satellites and Trojans

Sharkey,

Reddy,

Kuhn

et al. 2023

Planet. Sci. J.

View full text Add to dashboard Cite

show abstract

Surface Compositions of Trojan Asteroids

Emery,

Binzel,

Britt

et al. 2024

Space Sci Rev

View full text Add to dashboard Cite

The Jupiter Trojan asteroids are a key population for understanding the chemical and dynamical evolution of the Solar System. Surface compositions of Trojans, in turn, provide crucial information for reconstructing their histories. NASA’s Lucy mission will soon complete the first spacecraft reconnaissance of this population. This review summarizes the current state of knowledge of Trojan surface compositions and looks ahead to expected advances in that knowledge from Lucy. Surface compositions of Trojans remain uncertain due to a relative lack of diagnostic absorption features, though dedicated observations have begun to provide some clues to compositions. Trojans have uniformly low albedos, with a population average of ∼5.3%, and red spectral slopes at ultraviolet, visible, and near-infrared wavelengths. A bimodality of spectral slopes has been detected and confirmed across all these wavelengths, and the ratio of “less-red” to “red” Trojans increases with decreasing size. A broad absorption at ∼3.1 μm in some less-red Trojans may indicate the presence of N-H bearing material. Mid-infrared emissivity spectra reveal the presence of fine-grained anhydrous silicates on the surfaces. The meteorite collection contains no identifiable analogs to Trojan asteroids. Among small body populations, some Main Belt asteroids, comets, irregular satellites, and Centaurs provide reasonable spectral matches, supporting some genetic relationships among some members of these groups. The cause of the observed spectral properties remains uncertain, but recent suggestions include a combination of volatile ice sublimation and space weathering or a combination of impact gardening and space weathering. The Lucy mission will provide detailed compositional analysis of (3548) Eurybates, (15094) Polymele, (11351) Leucus, (21900) Orus, and (617) Patroclus-Menoetius, a suite of targets that sample the diversity among the Trojan population along several dimensions. With these flybys, the Lucy mission is poised to resolve many of the outstanding questions regarding Trojan surface compositions, thereby revealing how the Trojans formed and evolved and providing a clearer view of Solar System history.

show abstract

Ultraviolet Spectroscopy of Lucy Mission Targets with the Hubble Space Telescope

Cited by 2 publications

References 67 publications

Spectroscopic Links among Giant Planet Irregular Satellites and Trojans

Spectroscopic Links among Giant Planet Irregular Satellites and Trojans

Surface Compositions of Trojan Asteroids

Contact Info

Product

Resources

About