Joint Europa Mission (JEM): a multi-scale study of Europa to characterize its habitability and search for extant life

Europa is the closest and probably the most promising target to search for extant life in the Solar System, based on complementary evidence that it may fulfil the key criteria for habitability: the Galileo discovery of a sub-surface ocean; the many indications that the ice shell is active and may be partly permeable to transfer of chemical species, biomolecules and elementary forms of life; the identification of candidate thermal and chemical energy sources necessary to drive a metabolic activity near the ocean floor. In this article we are proposing that ESA collaborates with NASA to design and fly jointly an ambitious and exciting planetary mission, which we call the Joint Europa Mission (JEM), to reach two objectives: perform a full characterization of Europa's habitability with the capabilities of a Europa orbiter, and search for bio-signatures in the environment of Europa (surface, subsurface and exosphere) by the combination of an orbiter and a lander. JEM can build on the advanced understanding of this system which the missions preceding JEM will provide: Juno, JUICE and Europa Clipper, and on the Europa lander concept currently designed by NASA (Maize, report to OPAG, 2019). We propose the following overarching goals for our Joint Europa Mission (JEM): Understand Europa as a complex system responding to Jupiter system forcing, characterize the habitability of its potential biosphere, and search for life at its surface and in its sub-surface and exosphere. We address these goals by a combination of five Priority Scientific Objectives, each with focused measurement objectives providing detailed constraints on the science payloads and on the platforms used by the mission. The JEM observation strategy will combine three types of scientific measurement sequences: measurements on a high-latitude, low-altitude Europan orbit; in-situ measurements to be performed at the surface, using a soft lander; and measurements during the final descent to Europa's surface. The implementation of these three observation sequences will rest on the combination of two science platforms: a soft lander to perform all scientific measurements at the surface and sub-surface at a selected landing site, and an orbiter to perform the orbital survey and descent sequences. We describe a science payload for the lander and orbiter that will meet our science objectives. We propose an innovative distribution of roles for NASA and ESA; while NASA would provide an SLS launcher, the lander stack and most of the mission operations, ESA would provide the carrier-orbiter-relay platform and a stand-alone astrobiology module for the characterization of life at Europa's surface: the Astrobiology Wet Laboratory (AWL). Following this approach, JEM will be a major exciting joint venture to the outer Solar System of NASA and ESA, working together toward one of the most exciting scientific endeavours of the 21st century: to search for life beyond our own planet

Joint Europa Mission (JEM): a multi-scale study of Europa to characterize its habitability and search for extant life

Europa is the closest and probably the most promising target to search for extant life in the Solar System, based on complementary evidence that it may fulfil the key criteria for habitability: the Galileo discovery of a sub-surface ocean; the many indications that the ice shell is active and may be partly permeable to transfer of chemical species, biomolecules and elementary forms of life; the identification of candidate thermal and chemical energy sources necessary to drive a metabolic activity near the ocean floor. In this article we are proposing that ESA collaborates with NASA to design and fly jointly an ambitious and exciting planetary mission, which we call the Joint Europa Mission (JEM), to reach two objectives: perform a full characterization of Europa's habitability with the capabilities of a Europa orbiter, and search for bio-signatures in the environment of Europa (surface, subsurface and exosphere) by the combination of an orbiter and a lander. JEM can build on the advanced understanding of this system which the missions preceding JEM will provide: Juno, JUICE and Europa Clipper, and on the Europa lander concept currently designed by NASA (Maize, report to OPAG, 2019). We propose the following overarching goals for our Joint Europa Mission (JEM): Understand Europa as a complex system responding to Jupiter system forcing, characterize the habitability of its potential biosphere, and search for life at its surface and in its sub-surface and exosphere. We address these goals by a combination of five Priority Scientific Objectives, each with focused measurement objectives providing detailed constraints on the science payloads and on the platforms used by the mission. The JEM observation strategy will combine three types of scientific measurement sequences: measurements on a high-latitude, low-altitude Europan orbit; in-situ measurements to be performed at the surface, using a soft lander; and measurements during the final descent to Europa's surface. The implementation of these three observation sequences will rest on the combination of two science platforms: a soft lander to perform all scientific measurements at the surface and sub-surface at a selected landing site, and an orbiter to perform the orbital survey and descent sequences. We describe a science payload for the lander and orbiter that will meet our science objectives. We propose an innovative distribution of roles for NASA and ESA; while NASA would provide an SLS launcher, the lander stack and most of the mission operations, ESA would provide the carrier-orbiter-relay platform and a stand-alone astrobiology module for the characterization of life at Europa's surface: the Astrobiology Wet Laboratory (AWL). Following this approach, JEM will be a major exciting joint venture to the outer Solar System of NASA and ESA, working together toward one of the most exciting scientific endeavours of the 21st century: to search for life beyond our own planet

Eustachian tube dysfunction in candidates for surgery for obstructive sleep apnoea syndrome

AbstractBackgroundDefining the risk factors for Eustachian tube dysfunction can facilitate its prevention. It is hypothesised that Eustachian tube dysfunction as measured by the Eustachian Tube Dysfunction Questionnaire-7 is associated with obstructive sleep apnoea syndrome.MethodsThe questionnaire was systematically translated into Hebrew and validated in the accepted manner. This questionnaire was applied to obstructive sleep apnoea syndrome patients before and after expansion sphincter pharyngoplasty, in pre-set time intervals. The results were compared to those of controls from the general population.ResultsThirty-one patients (males:females = 19:12) were enrolled in the obstructive sleep apnoea syndrome group. Mean age was 43 years (range, 31–55 years) and mean body mass index was 28 kg/m2 (range, 27–30 kg/m2). Median apnoea-hypopnea index (pre-operatively) was 34 events per hour. The questionnaire scores in expansion sphincter pharyngoplasty candidates were significantly worse than in controls (p &lt; 0.001). Expansion sphincter pharyngoplasty did not change Eustachian tube function in the long term, but was associated with additional self-limiting Eustachian tube dysfunction in the first two post-operative months.ConclusionEustachian tube dysfunction is significantly worse in patients with obstructive sleep apnoea syndrome compared to controls. Expansion sphincter pharyngoplasty is not associated with Eustachian tube function improvement.</jats:sec

Calculated versus measured pure tone bone conduction 3 kHz thresholds in sudden sensorineural hearing loss

AbstractObjectiveTo compare the measured bone conduction threshold at 3 kHz with the calculated threshold in newly diagnosed sudden sensorineural hearing loss.MethodsA retrospective chart review was conducted of pure tone audiograms in confirmed sudden sensorineural hearing loss cases.ResultsOf 157 patients with sudden sensorineural hearing loss, 144 had idiopathic hearing loss, 8 had vestibular schwannoma and 5 had Ménière's disease. The r value for the correlation between the two methods of 3 kHz assessment for all patients was 0.887 (p &lt; 0.001). The mean difference between the measured and calculated 3 kHz thresholds was 0.76 ± 7.96 dB, 0.4 ± 8.08 dB and 1.5 ± 1.8 dB in the sudden sensorineural hearing loss, idiopathic and Ménière's disease groups, respectively. The mean difference between the measured and calculated 3 kHz thresholds was significantly greater in the vestibular schwannoma group (6.86 ± 4.38 dB) than in the idiopathic group (p = 0.013).ConclusionThe 3 kHz frequency may encompass important audiometric information. A discrepancy between the measured and calculated bone conduction 3 kHz thresholds raises suspicion of an underlying vestibular schwannoma as an aetiology for sudden sensorineural hearing loss, and these thresholds should therefore be measured independently and routinely.</jats:sec