Journal article
Dione's thermal inertia and bolometric Bond albedo derived from Cassini/CIRS observations of solar eclipse ingress
- Abstract:
- On 2010 May 18 Cassini's Composite Infrared Spectrometer (CIRS) observed Dione's leading hemisphere as its surface went into solar eclipse. Surface temperatures derived from each of CIRS' focal plane 3 (FP3, 600−1100 cm−1) show a rapid decrease in Dione's surface temperature upon eclipse ingress. This change was compared to the model surface emission to constrain bolometric Bond albedo and thermal inertia. Seven FP3 detectors were able to constrain the observed surface's thermophysical properties. The bolometric Bond albedo derived from these detectors are consistent with one another (0.54 ± 0.05 to 0.62 ± 0.03) and that of diurnal studies (e.g., 0.49 ± 0.11, Howett et al. 2014). This indicates that Dione's albedo is uniform to within the uncertainties across the observed region of its leading hemisphere. The derived thermal inertias are consistent across detectors, 9 ± 4 J m−2 K−1 s−1/2 (MKS) to 16 ± 8 MKS, and with previous diurnal studies (e.g., 8 to 12 MKS, Howett et al. 2014). The skin depth probed by the eclipse thermal wave is ∼0.6–1 mm, which is much shallower than that probed by diurnal cycles (∼50 mm). Thus, the agreement in thermal inertia between the eclipse and diurnal studies indicates that Dione's subsurface structure is uniform from submillimeter to subcentimeter depths. This is different from the Jovian system, where eclipse-derived thermal inertias are much lower than those derived from diurnal studies. The cause of this difference is not known, but one possibility is that the E-ring grains that bombard Dione's leading hemisphere overturn it, causing uniformity to centimeter depths.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 2.4MB, Terms of use)
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- Publisher copy:
- 10.3847/PSJ/ac82ab
Authors
- Publisher:
- IOP Publishing
- Journal:
- The Planetary Science Journal More from this journal
- Volume:
- 3
- Issue:
- 8
- Article number:
- 192
- Publication date:
- 2022-08-16
- Acceptance date:
- 2022-07-14
- DOI:
- EISSN:
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2632-3338
- Language:
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English
- Keywords:
- Pubs id:
-
1310392
- Local pid:
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pubs:1310392
- Deposit date:
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2023-04-03
Terms of use
- Copyright holder:
- Howett and Spencer
- Copyright date:
- 2022
- Rights statement:
- © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
- Licence:
- CC Attribution (CC BY)
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