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3 Planetary Satellites Inside Jupiter's Orbit
Pages 26-39

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From page 26...
... Lunar meteorites have been delivered to Earth throughout its history, and several hundred kilograms of lunar samples were returned to Earth deliberately during the Apollo program. Both crews and samples from Apollo 11, 12, and 14 were subjected to an elaborate quarantine and testing regime at the Lunar Receiving Laboratory to ensure that no harmful organisms were introduced to Earth's biosphere by returning astronauts, spacecraft, or extraterrestrial material (Allton et al., 1998~.1 Quarantine was ended after Apollo 14 NOTE: The planetary satellites examined in this study were selected based on scientific interest and the likelihood of possible sample return missions in the near future.
From page 27...
... Public Health Service, the Departments of Agriculture and the Interior, and the National Academy of Sciences to advise NASA on measures necessary for the prevention of contamination by lunar samples returned to Earth.
From page 28...
... The dynamical arguments discussed above are not easily reconciled with this interpretation, however, since such asteroids are most commonly found in the outer portions of the main belt. Taken together, then, the available data do not allow for a definitive answer about the compositions and internal histories of the martian satellites other than that they may have been broadly similar to those of similar-sized asteroids of carbonaceous, undifferentiated, and/or unknown composition.
From page 29...
... The Galilean Satellites of,Iupiter The four galilean satellites are large objects in low-inclination, low-eccentricity orbits around Jupiter. Their substantial size and the regularity of their orbits provide evidence that they formed via condensation and agglomeration from a primordial circumjovian nebula.
From page 30...
... Callisto is unlikely ever to have undergone significant tidal heating. The galilean satellites are therefore an extremely diverse group of objects in terms of their endowment of H2O, the fraction of that H2O that has been liquid, and the quantity of liquid that could have reached the surface.
From page 31...
... A crucial question from a biological standpoint is whether or not any of the subsurface H2O on Europa is liquid. Europa participates in the same three-body Laplace orbital resonance as Io, and as a result is also subjected to tidal heating.
From page 32...
... Indeed, investigation of Europa's biological potential forms much of the rationale for continued investigation of the satellite. In future exploration of Europa, a premium will be placed on sampling resurfaced regions that may contain materials brought up recently from deep below Europa's surface.
From page 33...
... In fact, extrusion of liquid rather than warm ice seemed plausible, given the lack of any observed viscous flow features in the Voyager images. Recent Galileo images have called into question the idea of cryovolcanism in Ganymede's grooved terrain.
From page 35...
... Because of the lack of data, it is uncertain whether there has been natural influx to Earth of material from the planetary satellites examined in this chapter. This direct evidence, along with the absence of indirect evidence for recent or past liquid water on the Moon, indicates that the potential for a living entity to be present in samples returned is negligible.
From page 36...
... may be present because of the Laplace orbital resonance relationship among Io, Europa, and Ganymede. Accordingly, the task group found that there is a potential for a living entity to be present in samples returned from Europa.
From page 37...
... Unlike samples from the Moon and Io, samples returned from Europa should be contained. The evidence for a liquid water ocean beneath the icy crust, first surmised from Voyager data and reinforced by Galileo data, coupled with a readily available energy source from its role in the Laplace orbital resonance relationship, makes Europa a prime target in the search for extraterrestrial life.
From page 38...
... Pp. 113-156 in Planetary Satellites, J.A.
From page 39...
... 1987. Tidal heating in an internal ocean model of Europa.


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