Moderate D/H ratios in methane ice on Eris and Makemake as evidence of hydrothermal or metamorphic processes in their interiors: Geochemical analysis

Glein, Christopher R.; Grundy, William M.; Lunine, Jonathan I.; Wong, Ian; Protopapa, Silvia; Pinilla-Alonso, Noemi; Stansberry, John A.; Holler, Bryan J.; Cook, Jason C.; Souza-Feliciano, Ana Carolina

doi:10.1016/j.icarus.2024.115999

Cited by 6 publications

(4 citation statements)

References 184 publications

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“…The derived column densities over both hemispheres suggest that CO 2 gas is less abundant than atmospheric O 2 , for which average column densities of 2-4 × 10 19 m −2 were inferred from observations (Cunningham et al 2015;Hartkorn et C and 13 C, can provide important information about the formation conditions of different icy bodies, the materials they accreted, and the processes that may have subsequently altered these materials. Prior studies have utilized isotopic ratios of remotely sensed spectral features on planetary bodies to gain insight into isotopic ratios of their constitutive elements (e.g., Clark et al 2019;Glein et al 2024;Grundy et al 2024). For example, 13 C/ 12 C ratios derived from equivalent width measurements of solid-state 13 CO 2 and 12 CO 2 on Saturn's native moon Iapetus are consistent with "terrestrial" values, exhibited by the inner planets, main belt asteroids, and Saturn's rings (Clark et al 2019).…”

Section: A Localized and Patchy Co 2 Atmospherementioning

confidence: 89%

Revealing Callisto’s Carbon-rich Surface and CO₂ Atmosphere with JWST

Cartwright,

Villanueva,

Holler

et al. 2024

Planet. Sci. J.

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We analyzed spectral cubes of Callisto’s leading and trailing hemispheres, collected with the NIRSpec Integrated Field Unit (G395H) on the James Webb Space Telescope. These spatially resolved data show strong 4.25 μm absorption bands resulting from solid-state 12CO2, with the strongest spectral features at low latitudes near the center of its trailing hemisphere, consistent with radiolytic production spurred by magnetospheric plasma interacting with native H2O mixed with carbonaceous compounds. We detected CO2 rovibrational emission lines between 4.2 and 4.3 μm over both hemispheres, confirming the global presence of CO2 gas in Callisto’s tenuous atmosphere. These results represent the first detection of CO2 gas over Callisto’s trailing side. The distribution of CO2 gas is offset from the subsolar region on either hemisphere, suggesting that sputtering, radiolysis, and geologic processes help sustain Callisto’s atmosphere. We detected a 4.38 μm absorption band that likely results from solid-state 13CO2. A prominent 4.57 μm absorption band that might result from CN-bearing organics is present and significantly stronger on Callisto’s leading hemisphere, unlike 12CO2, suggesting these two spectral features are spatially antiassociated. The distribution of the 4.57 μm band is more consistent with a native origin and/or accumulation of dust from Jupiter’s irregular satellites. Other, more subtle absorption features could result from CH-bearing organics, CO, carbonyl sulfide, and Na-bearing minerals. These results highlight the need for preparatory laboratory work and improved surface–atmosphere interaction models to better understand carbon chemistry on the icy Galilean moons before the arrival of NASA’s Europa Clipper and ESA’s JUICE spacecraft.

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Section: A Localized and Patchy Co 2 Atmospherementioning

confidence: 89%

Revealing Callisto’s Carbon-rich Surface and CO₂ Atmosphere with JWST

Cartwright,

Villanueva,

Holler

et al. 2024

Planet. Sci. J.

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“…A.9. Discussion: 13 CO/ 12 CO Isotopic Ratios Prior studies have used remotely sensed H 2 O, HDO/D 2 O ice, 12 CH 4 , 13 CH 4 , 12 CH 3 D, 13 CO 2 , and 12 CO 2 spectral features to estimate D/H and 13 C/ 12 C isotopic ratios and gain insight into the formation conditions for different icy bodies and possible endogenic sources of material on their surfaces (Clark et al 2019;Cartwright et al 2024;Glein et al 2024;Grundy et al 2024b). Ariel's strong 12 CO 2 scattering peaks make reliable determination of its 13 CO 2 / 12 CO 2 isotopic ratios difficult from analysis of ν 3 band parameters for 12 CO 2 , and we did not attempt to retrieve a 12 CO 2 abundance from other spectral features (e.g., at 4.90 μm).…”

Section: A8 Discussion: Comparison Between Ariel and Co 2 -Bearing Tnosmentioning

confidence: 99%

JWST Reveals CO Ice, Concentrated CO₂ Deposits, and Evidence for Carbonates Potentially Sourced from Ariel’s Interior

Cartwright,

Holler,

Grundy

et al. 2024

ApJL

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The Uranian moon Ariel exhibits a diversity of geologically young landforms, with a surface composition rich in CO2 ice. The origin of CO2 and other species, however, remains uncertain. We report observations of Ariel’s leading and trailing hemispheres, collected with NIRSpec (2.87–5.10 μm) on the James Webb Space Telescope. These data shed new light on Ariel's spectral properties, revealing a double-lobed CO2 ice scattering peak centered near 4.20 and 4.25 μm, with the 4.25 μm lobe possibly representing the largest CO2 Fresnel peak yet observed in the solar system. A prominent 4.38 μm 13CO2 ice feature is also present, as is a 4.90 μm band that results from 12CO2 ice. The spectra reveal a 4.67 μm 12CO ice band and a broad 4.02 μm band that might result from carbonate minerals. The data confirm that features associated with CO2 and CO are notably stronger on Ariel’s trailing hemisphere compared to its leading hemisphere. We compared the detected CO2 features to synthetic spectra of CO2 ice and mixtures of CO2 with CO, H2O, and amorphous carbon, finding that CO2 could be concentrated in deposits thicker than ∼10 mm on Ariel’s trailing hemisphere. Comparison to laboratory data indicates that CO is likely mixed with CO2. The evidence for thick CO2 ice deposits and the possible presence of carbonates on both hemispheres suggests that some carbon oxides could be sourced from Ariel’s interior, with their surface distributions modified by charged particle bombardment, sublimation, and seasonal migration of CO and CO2 from high to low latitudes.

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“…Methane present on the surface of Pluto and other icy bodies is thought to have been emitted from the interior of the planetesimals by cryovolcanic degassing (Glein et al, 2024;Moore & McKinnon, 2021). These planetary surfaces are, however, exposed to irradiation by cosmic and sun rays, which likely partially destroys CH 4 (Hudson et al, 2008).…”

Section: Methane Clumped Signatures In Astrobiologymentioning

confidence: 99%

“…It is also detected on the surface of icy bodies present in the trans-Neptunian region of the solar system. This includes Triton, Pluto and Charon (Cruikshank et al, 1998;Grundy et al, 2016;Owen et al, 1993), and of at least two dwarf planets with trans-Neptunian orbits (Glein et al, 2024;Grundy et al, 2024). In addition, methane has been recently observed in the atmosphere of the gaseous giant exoplanet WASP-80b atmosphere (Bell et al, 2023).…”

Section: Methane Clumped Signatures In Astrobiologymentioning

confidence: 99%

Clumped Isotope Signatures of Abiotic Methane: The Role of the Combinatorial Isotope Effect

Labidi,

McCollom,

Giunta

et al. 2024

JGR Solid Earth

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Methane clumped isotope signatures of abiogenesis may be diagnostic of the origin of methane on Earth and other planetary bodies. We performed synthesis of abiogenic methane in hydrothermal conditions between 130 and 300°C and determined δ13C, δD, Δ13CH3D, and Δ12CH2D2. The experiments were performed by heating water in the presence of Fe0 powder and CO. The reduction of water on metallic iron led to the formation of H2. CO was reacted with both H2 and H2O, generating both CH4 and CO2. Methane δ13C values are isotopically depleted by ∼25‰ relative to the CO starting material. This is consistent with carbon isotopic equilibrium between methane, carbon monoxide and carbon dioxide in our experiments. In contrast, D/H ratios are inconsistent with equilibrium isotopic fractionation, as illustrated by δD values of methane fractionated by ∼500‰ relative to starting H2O. This suggests that under our experimental conditions, hydrogen additions to carbon may be governed by kinetics. Δ13CH3D values track experimental temperature, with values between +1.5‰ and +5.0‰ for most samples. In contrast, Δ12CH2D2 values are displaced from equilibrium. We find exclusively negative Δ12CH2D2 values, showing deficits down to 40‰ relative to thermodynamic equilibrium. We interpret the data as evidence for distinct, kinetically induced D/H pools contributing to methane assembly, that is, a combinatorial effect. The cumulative D/H fractionations associated with CO hydrogenation explain the direction and magnitude of Δ12CH2D2 values during abiotic methane formation. We suggest that near equilibrium Δ13CH3D with negative Δ12CH2D2 signatures will help identify methane formed abiotically in nature.

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Moderate D/H ratios in methane ice on Eris and Makemake as evidence of hydrothermal or metamorphic processes in their interiors: Geochemical analysis

Cited by 6 publications

References 184 publications

Revealing Callisto’s Carbon-rich Surface and CO₂ Atmosphere with JWST

Revealing Callisto’s Carbon-rich Surface and CO₂ Atmosphere with JWST

JWST Reveals CO Ice, Concentrated CO₂ Deposits, and Evidence for Carbonates Potentially Sourced from Ariel’s Interior

Clumped Isotope Signatures of Abiotic Methane: The Role of the Combinatorial Isotope Effect

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Moderate D/H ratios in methane ice on Eris and Makemake as evidence of hydrothermal or metamorphic processes in their interiors: Geochemical analysis

Cited by 6 publications

References 184 publications

Revealing Callisto’s Carbon-rich Surface and CO2 Atmosphere with JWST

Revealing Callisto’s Carbon-rich Surface and CO2 Atmosphere with JWST

JWST Reveals CO Ice, Concentrated CO2 Deposits, and Evidence for Carbonates Potentially Sourced from Ariel’s Interior

Clumped Isotope Signatures of Abiotic Methane: The Role of the Combinatorial Isotope Effect

Contact Info

Product

Resources

About

Revealing Callisto’s Carbon-rich Surface and CO₂ Atmosphere with JWST

Revealing Callisto’s Carbon-rich Surface and CO₂ Atmosphere with JWST

JWST Reveals CO Ice, Concentrated CO₂ Deposits, and Evidence for Carbonates Potentially Sourced from Ariel’s Interior