Quantitative Characterization of Lunar Mare Orientale Basalts Detected by Moon Mineralogical Mapper on Chandrayaan-1 - Planetary Exploration and Science: Recent Results and Advances - page 28

measurements are increasingly being used to investigate the surfaces of planetary
bodies throughout the solar system. The reflectance spectra of rocks exhibit
characteristic signatures depending upon the mineralogy, chemical composition,
and physical properties. Remotely obtained spectra in the visible and near-infrared
wavelength regions can provide information on the mineralogy and modal abun-
dance of a planetary surface (Adams 1974 , 1975 ). The minerals can be identified
based on spectral features, including absorptions pattern, the parameter structures,
absorption band positions, band strength, and band depth, which are directly related
to mineral chemistry (Hunt and Salisbury 1970 , 1971 ). The same principle can be
adopted to map the mineralogical compositions of objects in the outer space. The
visible and near-infrared reflectance spectra of mature lunar soils have been used to
classify the mare basalts from the nearside of the moon (McCord et al. 1976 ; Pieters
1978 ;BVSP 1981 ).
The spectral profiles of the Mare Orientale, Lacus Veris, and Autumni were
collected randomly from the preprocessed M 3 data. From the collected spectral
profiles, the average spectrum has been taken for further analysis. From the spectra,
it is observed that, there are two broad major absorption features at 950 and
2,100 nm due to dominance of clinopyroxene and minor amount of olivine content.
Another insignificant absorption is located at 1,260 nm due to plagioclase content
of the basaltic terrain. The spectra of the three test sites are shown in Fig. 2.3 .To
avoid the maturity effect of the mare soil in the spectra, the spectral profiles were
collected in the fresh shallow impact craters. There is much variation observed in
between the spectra from fresh shallow impact craters and that from the dark color
matured mare soils. From the matured mare soil spectra, it is difficult to delineate
the basaltic mineralogy.
Based on the morphological features, the spectral profiles have drawn for the
preliminary understating of the rock types and their mineralogy. From this spectral
profile, it has been understood that the dominant minerals of this region are

0.25

Mare Orientale
Lacus Veris
Lacus Autumni

0.20

0.15

0.10

0.05

500 1000 1500 2000 2500

Wavelength nm

Fig. 2.3 Mare Orientale, Lacus Veris and Lacus Autumni spectra