| Name | OT2_elellouc_3 |
| Title | Probing the Enceladus torus with Herschel |
| URL | http://archives.esac.esa.int/hsa/whsa-tap-server/data?retrieval_type=OBSERVATION&observation_id=1342238538&instrument_name=HIFI&product_level=LEVEL0&compress=true |
| DOI | https://doi.org/10.5270/esa-nje3mcf |
| Author | lellouch, e. |
| Description | Observations of Saturn with HIFI, performed in 2009 and 2010 have revealed absorptions in the core of several emission lines of water from Saturn.s atmosphere. They are due to absorption from water in the Enceladus water torus, a cloud of material originating from Enceladus. active plumes and spreading around Saturn to form a broad toroidal structure centered at Enceladus. orbit. These data permit to determine water column densities in the torus equatorial plane and allow a first estimate of the torus vertical extent and dynamical structure. Comparison with physical models indicates an Enceladus source rate of virgul10^28 water molecules s^-1, and suggests that Enceladus. activity is the ultimate source of water in Saturn.s atmosphere (Hartogh et al. 2011).These H2O observations thus provide an entirely new method to probe physical conditions (density, structure, kinematics) in the Enceladus torus and to monitor Enceladus venting activity. As such, they are highly complementary to the Cassini measurements, which characterize the source region but cannot sample water away from Enceladus and have led to contradictory results as to the stability/variability of plume activity. Additional observations of these H2O lines have been acquired in December 2010 and July 2011. We propose to (i) continue to monitor the variation of these absorptions with viewing geometry and time, taking advantage of the change of aspect in the Saturn system over the upcoming years (ii) search for H2O emission directly originating from the torus (iii) monitor the water emission from Saturn, which from the July 2011 observations was shown to be enhanced in relation by to the current major storm developing in Saturn.s Northern hemisphere.The ensemble of data, along with torus models developed by our team, will provide us with an improved understanding of the torus three-dimensional structure, the excitation conditions for water in the torus, and the variation timescales of Enceladus cryo-volcanic activity. |
| Publication | |
| Instrument | HIFI_HifiMapping_raster, HIFI_HifiPoint_dbs |
| Temporal Coverage | 2012-01-31T22:06:35Z/2013-01-31T23:29:36Z |
| Version | SPG v14.1.0 |
| Mission Description | Herschel was launched on 14 May 2009! It is the fourth cornerstone mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities. |
| Creator Contact | https://support.cosmos.esa.int/h®erschel/ |
| Date Published | 2013-07-31T23:16:53Z |
| Keywords | Herschel, HSC, submillimetre, far-infrared, HIFI, PACS, SPIRE |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, lellouch et al., 2013, 'Probing the Enceladus torus with Herschel', SPG v14.1.0, European Space Agency, https://doi.org/10.5270/esa-nje3mcf |