Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface?
At the beginning of the Cassini mission, the ISS (Imaging Science Subsystem) and CIRS (Composite Infra-Red Spectrometer) instruments discovered a geologically active region at the south pole of Saturn's moon Enceladus (e.g. Porco et al., 2005). Plumes venting material emanate from this region....
Main Authors: | , , , , , , , |
---|---|
Other Authors: | , , , , , , , , |
Format: | Conference Object |
Language: | English |
Published: |
HAL CCSD
2012
|
Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-00768858 |
id |
ftccsdartic:oai:HAL:hal-00768858v1 |
---|---|
record_format |
openpolar |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
Surface materials and properties Saturnian satellites Remote sensing [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] |
spellingShingle |
Surface materials and properties Saturnian satellites Remote sensing [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] Le Gall, Alice Leyrat, Cedric Janssen, Michael A. Stolzenbach, Aurélien Wye, Lauren C. West, Richard D. Lorenz, Ralph D. Mitchell, Karl L. Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? |
topic_facet |
Surface materials and properties Saturnian satellites Remote sensing [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] |
description |
At the beginning of the Cassini mission, the ISS (Imaging Science Subsystem) and CIRS (Composite Infra-Red Spectrometer) instruments discovered a geologically active region at the south pole of Saturn's moon Enceladus (e.g. Porco et al., 2005). Plumes venting material emanate from this region. Six years later, on November 6, 2011, the first-ever Synthetic Aperture Radar (SAR) image of Enceladus was acquired during the E16 flyby of the moon at the wavelength of 2-cm (Mitchell et al., AGU 2011). The SAR swath is located within the seemingly young South Pole Terrains, not far from the active sulci also known as the "tiger stripes" identified as the sources of the plumes. Concurrently to the SAR image, radiometry data were collected in the passive mode of the instrument with a ground footprint of 25-40 km across the track and ~5 km along. The Cassini radiometer records the thermal emission from the surface in the microwave domain, at 2-cm. More specifically, it measures the brightness temperature of the surface that varies both with the emissivity and the vertical temperature profile below the surface down to a depth, which depends on the electrical properties of the subsurface. Typically, radio instruments sense 10 to 100 wavelengths into an icy crust and can thus provide unique insight into the compositional, thermal and physical (porosity, roughness) state of planetary regoliths at depths much greater than the ones sampled by thermal IR spectrometers. In particular, microwave radiometer can be used to detect possible endogenic activity beneath the surface. The measured calibrated brightness temperatures during E16 cover a range from 33 to 60 K. In order to analyze these dataset, we have modeled the expected thermal emission from Enceladus' surface. In absence of endogenic emission, the temperature structure of any airless satellite results from a balance between solar insolation, heat transport within the subsurface and reradiation outward. The developed thermal model accounts not only for the diurnal but also ... |
author2 |
PLANETO - LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) Jet Propulsion Laboratory (JPL) California Institute of Technology (CALTECH)-NASA Stanford University |
format |
Conference Object |
author |
Le Gall, Alice Leyrat, Cedric Janssen, Michael A. Stolzenbach, Aurélien Wye, Lauren C. West, Richard D. Lorenz, Ralph D. Mitchell, Karl L. |
author_facet |
Le Gall, Alice Leyrat, Cedric Janssen, Michael A. Stolzenbach, Aurélien Wye, Lauren C. West, Richard D. Lorenz, Ralph D. Mitchell, Karl L. |
author_sort |
Le Gall, Alice |
title |
Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? |
title_short |
Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? |
title_full |
Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? |
title_fullStr |
Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? |
title_full_unstemmed |
Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? |
title_sort |
cassini microwave radiometry observations of enceladus' south pole: detection of a warm subsurface? |
publisher |
HAL CCSD |
publishDate |
2012 |
url |
https://hal.archives-ouvertes.fr/hal-00768858 |
op_coverage |
San Francisco, United States |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
AGU Fall Meeting https://hal.archives-ouvertes.fr/hal-00768858 AGU Fall Meeting, Dec 2012, San Francisco, United States |
op_relation |
hal-00768858 https://hal.archives-ouvertes.fr/hal-00768858 |
_version_ |
1766201486024376320 |
spelling |
ftccsdartic:oai:HAL:hal-00768858v1 2023-05-15T18:22:07+02:00 Cassini microwave radiometry observations of Enceladus' South Pole: Detection of a warm subsurface? Le Gall, Alice Leyrat, Cedric Janssen, Michael A. Stolzenbach, Aurélien Wye, Lauren C. West, Richard D. Lorenz, Ralph D. Mitchell, Karl L. PLANETO - LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) Jet Propulsion Laboratory (JPL) California Institute of Technology (CALTECH)-NASA Stanford University San Francisco, United States 2012-12-03 https://hal.archives-ouvertes.fr/hal-00768858 en eng HAL CCSD hal-00768858 https://hal.archives-ouvertes.fr/hal-00768858 AGU Fall Meeting https://hal.archives-ouvertes.fr/hal-00768858 AGU Fall Meeting, Dec 2012, San Francisco, United States Surface materials and properties Saturnian satellites Remote sensing [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] info:eu-repo/semantics/conferenceObject Conference papers 2012 ftccsdartic 2021-11-21T03:57:10Z At the beginning of the Cassini mission, the ISS (Imaging Science Subsystem) and CIRS (Composite Infra-Red Spectrometer) instruments discovered a geologically active region at the south pole of Saturn's moon Enceladus (e.g. Porco et al., 2005). Plumes venting material emanate from this region. Six years later, on November 6, 2011, the first-ever Synthetic Aperture Radar (SAR) image of Enceladus was acquired during the E16 flyby of the moon at the wavelength of 2-cm (Mitchell et al., AGU 2011). The SAR swath is located within the seemingly young South Pole Terrains, not far from the active sulci also known as the "tiger stripes" identified as the sources of the plumes. Concurrently to the SAR image, radiometry data were collected in the passive mode of the instrument with a ground footprint of 25-40 km across the track and ~5 km along. The Cassini radiometer records the thermal emission from the surface in the microwave domain, at 2-cm. More specifically, it measures the brightness temperature of the surface that varies both with the emissivity and the vertical temperature profile below the surface down to a depth, which depends on the electrical properties of the subsurface. Typically, radio instruments sense 10 to 100 wavelengths into an icy crust and can thus provide unique insight into the compositional, thermal and physical (porosity, roughness) state of planetary regoliths at depths much greater than the ones sampled by thermal IR spectrometers. In particular, microwave radiometer can be used to detect possible endogenic activity beneath the surface. The measured calibrated brightness temperatures during E16 cover a range from 33 to 60 K. In order to analyze these dataset, we have modeled the expected thermal emission from Enceladus' surface. In absence of endogenic emission, the temperature structure of any airless satellite results from a balance between solar insolation, heat transport within the subsurface and reradiation outward. The developed thermal model accounts not only for the diurnal but also ... Conference Object South pole Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) South Pole |