4.The lunar poles arespecial environments that may bear witness to the volatile flux over the latter part of solar system history

Primary understanding of polar environment (photometry, morphology, topography, temperature, and distribution and inventory of volatiles).

High-spatial-resolution distribution of volatiles on and in the regolith poleward of 70 degrees.

Cryogenically preserved sample return to determine the complexity of the polar deposits.

Understand physical properties of polar regolith. Determinethe localized character and lateral and vertical distribution of polar deposits. Measure chemical and isotopic composition and physical and mineralogical characteristics.

Human-assisted robotic exploration of regolith.

5. Lunar volcanism provides a window into the thermal and compositional evolution of the Moon.

Detailed global elemental and mineralogical information in a spatial context. Improved age-dating for basalts through crater counting.

Stratigraphy of specific basalt flows (subsurface sounding). High-spatial-resolution compositional data desirable.

Sample the youngest and oldest basalt flows. Need samples from unsampled benchmark lava flows and pyroclastic deposits.

Strategic site selection. Conduct in situ analyses and mineralogical and elemental characterization of the rocks and provide a thorough description of the geologic context.

Strategic site selection, core drilling, and active subsurface sounding to determine layering and volume. Sample a complete sequence of flows to determine the evolution of basalt composition.

6. The Moon is an accessible laboratory for studying the impact process on planetary scales.

Detailed geologic mapping of compositionally diverse craters and basins.

Evaluation of upper-surface stratigraphy (sounding). Determination of the shape of craters and the distribution of ejecta.

Sample returns from benchmark craters and basins.

In situ compositional and structural analyses of craters and basins (via traverses).

Core samples from impact-melt sheets. Traverses across ejecta blankets.

7. The Moon is anatural laboratory for regolith processes andweathering on anhydrous airless bodies.

Maps of regolith maturity and derivation of the temporal progression of space weathering. Identification of regions that contain ancient regolith.

Evaluation of upper-surface stratigraphy (sounding).

Regolith from unsampled terrain of diverse composition and age. Understand the evolution of the regolith. Sample old regolith where it is stratigraphically preserved.

Characterization of returned sample environment.

Obtain paleoregolith samples (exposed in selected outcrops or through deep drilling).

8. Processes involved with the atmosphere and dust environment of the Moon are accessible for scientific study while the environment remains in a pristine state.

Characterize surface electric field; dust grain size, charge, and spatial distribution, and effects of human activity on dust environment.

Variation in mass with time and compositional inventory (“with time” refers to the lunar diurnal and Earth-orbital/solar cycles).

Not applicable. Sample return not currently feasible.

Variation of mass withtime and identification of dominant species. Environmental monitoring near human activity. Measure electric field and dust environment.

Not applicable. Human presence will alter atmospheric characteristics.

NOTE: Acronyms are defined in Appendix B.

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