Spectro-Polarimetric Surveyof the Lunar Surface

김성수경희대학교

우주탐사회 워크샵 , 2014 년 2 월

Spectro-Polarimetric Imaging

• The Lunar Regolith– Exposure to charged particles and micrometeor bombardment causes

• accumulation of nanophase reduced iron (npFe0) on lunar regolith grains,• decrease in grain size,• enrichment with glass material and agglutinates.

– Measurements of the grain-size distributions will aid in the evaluation of dusty lunar environments both for human sorties and potential sites for lunar facilities.

– Composition and grain size distribution, and the effects of space weathering are also crucial for understanding the structure and evolution of the Moon.

– The evolution of from immature to mature grains is manifested in their spectral and polarimetric properties.

– But, none of the recent or planned lunar orbiter missions are equipped with polarimetric optics.

Reference: Hines, D.C., Shkuratov, Y., Kreslavsky, M., Schneider, G., Videen, G., Sitko, M., Hammel, H.B., & Wolff, M., 2008, "Probing the Lunar Surface Using Spatially Resolved Optical and Near-IR Imaging Polarimetry with HST/ACS and HST/NICMOS", a "white paper" in response to “Lunar Science with HST” initiative solicited by STScI.

Evolution of Grain Sizes

Observed Polarizations

Observed Polarizations

Estimation of Particle Sizes

3 1.37max 10 (0.021 1.76)P d A

Observations at Lick

경희대학교 Lick 천문대

Polarimetry at 5 Bands

경희대학교 Lick 천문대

Polarimetry at 5 Bands

Polarimetry at 5 Bands

Wavelength dependency of c1 parameters

3 1.37max 10 (0.021 1.76)P d A

Thorium and Titanium maps

c1(u)/c1(i)

TitaniumThorium