Plume and Surface Composition of Enceladus

Postberg, F.; Clark, R. N.; Hansen, C. J.; Coates, A. J.; Ore, C. M. Dalle; Scipioni, F.; Hedman, M. M.; Waite, J. H.

doi:10.2458/azu_uapress_9780816537075-ch007

Cited by 39 publications

(60 citation statements)

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“…Plume material venting from Enceladus are composed of a mixture of water ice, salts, silica particles, and organic material (Postberg et al 2018a). The ejected material is thought to be travelling at velocities in the range of 80 m s −1 to 2 km s −1 (Hedman et al 2009;Perry et al 2016) and velocities between 7.5 to 17 km s −1 were experienced by the Cassini spacecraft as it passed through the plume (Postberg et al 2018a). Therefore, laboratory based experiments simulating the ejection of material or sample collection conditions would be required to assist in the interpretation of data being collected.…”

Section: Plume and Sample Collectionmentioning

confidence: 99%

Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans

Taubner

Olsson-Francis

Vance³

et al. 2020

Space Sci Rev

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The icy satellites of Jupiter and Saturn are perhaps the most promising places in the Solar System regarding habitability. However, the potential habitable environments are hidden underneath km-thick ice shells. The discovery of Enceladus' plume by the Cassini mission has provided vital clues in our understanding of the processes occurring within the interior of exooceans. To interpret these data and to help configure instruments for future missions, controlled laboratory experiments and simulations are needed. This review aims

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Section: Plume and Sample Collectionmentioning

confidence: 99%

Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans

Taubner

Olsson-Francis

Vance³

et al. 2020

Space Sci Rev

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“…Estimates for the gas-to-ice ratio in the plume vary greatly, ranging from 30 to 1.5. However, the latest estimates settle around a value of 10 Postberg et al 2018a). The plume is also known to be time-variable.…”

Section: Environmental Conditions and Engineering Constraintsmentioning

confidence: 99%

Key Technologies and Instrumentation for Subsurface Exploration of Ocean Worlds

Dachwald

Ulamec

Postberg³

et al. 2020

Space Sci Rev

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In this chapter, the key technologies and the instrumentation required for the subsurface exploration of ocean worlds are discussed. The focus is laid on Jupiter's moon Europa and Saturn's moon Enceladus because they have the highest potential for such missions in the near future. The exploration of their oceans requires landing on the surface, penetrating the thick ice shell with an ice-penetrating probe, and probably diving with an underwater vehicle through dozens of kilometers of water to the ocean floor, to have the chance to find

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“…Comparison of the suprathermal heavy ion measurements from the three planets allows us to utilize the abundant Jovian S + measurement peak as a fiducial at 32 amu/e, which, when combined with the uncomplicated observations of MI escape from Saturn's magnetosphere, allows us to more clearly identify Earth's magnetospheric MI populations. Four molecular ions at Saturn, CO + , N 2 + , HCNH + , and C 2 H 4 + , have now been suggested or identified in particle fluxes at Saturn that could possibly contribute to the ubiquitous suprathermal heavy ion signal with an atomic mass of 28 amu that is observed in and near Saturn's magnetosphere (Waite et al, 2009;Westlake, Paranicas, et al, 2012;Mandt et al, 2012;Postberg et al, 2018). CO, N 2 , and HCNH are among the molecules with the strongest chemical bonds in chemistry (Kalescky et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

“…Once released somewhere in Saturn's magnetosphere, either near Saturn's rings, Enceladus, or Titan, any one of the three should likely persist long enough to ionize (if neutral on release), circulate, and be accelerated to suprathermal energies. Note though that some of the relatively abundant CO 2 in the Enceladus plumes (Postberg et al, 2018;Waite et al, 2006Waite et al, , 2009) might evolve into the observed CO + through dissociation in the high-energy charged particle environment near~4 R S . Waite et al (2006Waite et al ( , 2009 argued that the dominant neutral 28-amu thermal energy molecule in the Enceladus plume was more likely N 2 or C 2 H 4 rather than CO, citing corroborating measurements from other Cassini instruments.…”

Section: Introductionmentioning

confidence: 99%

Suprathermal Magnetospheric Atomic and Molecular Heavy Ions at and Near Earth, Jupiter, and Saturn: Observations and Identification

Christon¹,

Hamilton

Mitchell

et al. 2020

JGR Space Physics

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We examine long-term suprathermal, singly charged heavy ion composition measured at three planets using functionally identical charge-energy-mass ion spectrometers, one on Geotail, orbiting Earth at 9-30 Re, the other on Cassini, in interplanetary space, during Jupiter flyby, and then in orbit around Saturn. O + , a principal suprathermal (~80-220 keV/e) heavy ion in each magnetosphere, derives primarily from outflowing ionospheric O + at Earth, but mostly from satellites and rings at Jupiter and Saturn. Comparable amounts of Iogenic O + and S + are present at Jupiter. Ions escaping the magnetospheres: O + and S + at Jupiter; C + , N + , O + , H 2 O + , 28 M + (possibly an aggregate of the molecular ions, MI, CO + , N 2 + , HCNH + , and/or C 2 H 4 + ), and O 2 + at Saturn; and N + , O + , N 2 + , NO + , O 2 + , and Fe + at Earth. Generally, escaped atomic ions (MI) at Earth and Saturn have similar (higher) ratios to O + compared to their magnetospheric ratios; Saturn's H 2 O + and Fe + ratios are lower. At Earth, after O + and N + , ionospheric origin N 2 + , NO + , and O 2 + (with proportions~0.9:1.0:0.2) dominate magnetospheric heavy ions, consistent with recent high-altitude/latitude ionospheric measurements and models; average ion count rates correlate positively with geomagnetic and solar activity. At~27-33 amu/e, Earth's MIs dominate over lunar pickup ions (PUIs) in the magnetosphere; MIs are roughly comparable to lunar PUIs in the magnetosheath, and lunar PUIs dominate over MIs beyond Earth's bow shock. Lunar PUIs are detected at~39-48 amu/e in the lobe and possibly in the plasma sheet at very low levels.Plain Language Summary Some of the air we breathe, a gas of~78% N 2 and~21% O 2 molecules, expands into the high-altitude atmosphere, the thermosphere, and becomes ionized by sunlight and charged particles from space to become the ionosphere. Molecules can break up into their component atoms or combine with other ions to form other molecules. Some ionospheric ions flow out into space, mostly during geomagnetic disturbances, and are further energized. Magnetospheres, plasma bubbles filled with these energized particles, form around planets with magnetic fields, like the Earth whose magnetic field stands off the steady stream of ions and electrons from the Sun called the solar wind. Particles inside the bubbles can be planet or satellite origin, and outside the bubble, they are mostly Sun origin. However, some inside get out and some outside get in. Improved ion measurements from space give us information to help unravel both the outflowing particles' interactions on the way out and when and how ions escape or penetrate magnetospheres. Planets' satellites and rings also contribute ionized and neutral particles to the mix, making various determinations more difficult than others. Ions from solar wind and sunlight impacting Earth's satellite, the Moon, which spends most of its time outside Earth's magnetosphere, dominate ion composition at some masses and energies there while contributing little overall inside...

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Plume and Surface Composition of Enceladus

Cited by 39 publications

References 0 publications

Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans

Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans

Key Technologies and Instrumentation for Subsurface Exploration of Ocean Worlds

Suprathermal Magnetospheric Atomic and Molecular Heavy Ions at and Near Earth, Jupiter, and Saturn: Observations and Identification

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