Space Science in the Twenty-First Century Imperatives for the Decades 1995 to 2015, Overview (1988) / Chapter Skim
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3. Planetary and Lunar Exploration
3. Planetary and Lunar Exploration
Pages 15-26
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From page 15... ...
The same questions continue to preoccupy modern planetary science as well. Planetary studies illuminate some of the deepest and longeststanding scientific questions.
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From page 16... ...
To understand how the planets evolved, including Earth and the planetary satellites, and to understand their present states; ~ To learn what conditions led to the origin of life; . To learn how physical laws work In large systems.
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From page 17... ...
Conversely, planetary investigations of objects that evolved under conditions far different from those on Earth may prod us to seek a deeper grasp of natural terrestrial phenomena, as well as a more complete understanding of Earth's history. By exposing circumstances in which concepts based on terrestrial analogs fail, planetary investigations help us define the limits of applicability of these Earth-based ideas.
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From page 18... ...
Investigation of large-scale physical processes involves virtually all of the objects in the solar system. The giant planets provide clues about properties of matter under high pressures; planetary interiors and magnetospheres demonstrate the curious behaviors of magnetized fluids and plasmas; Ad planetary atmospheres and surfaces present puzzles about the long-term evolution of complex interacting systems that constitute planetary environments and interiors.
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From page 19... ...
On Earth, geological processes have obliterated Al but a few relatively recent craters, including one from an impact that may have caused mass extinctions at the end of the Cretaceous era some 65 minion years ago. Recent theories explain the anomalous densities of Moon (Iow)
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From page 20... ...
Beyond 1995, planetary exploration will shift increasingly toward orbiters, atmospheric probes, landers, sample returns, and perhaps manned exploration the type of research required for a more complete understanding of the solar system. To complement these in situ investigations we will require laboratory experunentation and theoretical analysis as well.
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From page 21... ...
Recommended Program: Post-1995 Over the Midyear interval from 1995 to 2015, the recommended program encompasses investigations of all of the major planetary bodies in the solar system along with selected satellites and primitive objects. Terrestrial Planets Lanclers, rovers, selected sample returns, and networks of automated observation stations on planetary surfaces wiD be the primary systems used to study the terrestrial planets.
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From page 22... ...
~ situ studies of selected satellites will collect Formation pertaining to the primordial state of the volatile and organic matter in the solar system, and may yield clues about prebiotic chemical evolution. Recommended Missions I
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From page 23... ...
We wild thus obtain insights into processes in the protoplanetary nebula and explore early evolutionary mechanisms. ~ situ studies of comets and small outer solar system objects will permit analysis of the most complete an<]
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From page 24... ...
Meeting this challenge wiD require comparative studies of the terrestrial planets, including detailed studies of the changes that individual planetary environments undergo. Of particular interest in the comparison of terrestrial planets Is the puzzle posed by the triad of planets with atmospheres: Venus,
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From page 25... ...
It is evident that detailed study of the martian surface will yield information about the character of the planet's early environments, their arrangement in time, and perhaps clues as to the influences that produced such marked environmental change. Of all the planets beyond Earth, Mars is the one most access sible to detailed study.
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From page 26... ...
Tbe recommended investigations wO1 Ego prowls the 1~ airman needed tar proper plug of later waned exploratory Salons to the Coon and planets.
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