Many small, fresh craters bear signatures of water (H2O) and hydroxyl (OH)detected as absorption of IR in the range of 3 micrometers by NASA's Moon Mineralogy Mapper. Fig. A on left shows feldspar-rich terrain on the Moon's far side. The arrows point to the location of small, fresh craters. Fig. B on right indicates reflectance as a function of wavelength for the craters in Fig. A. The water and hydroxyl signature in these regions is seen as a characteristic dip in reflectance of IR near the 3-micrometer band, a region noted with a light-blue band. The dashed line shows background regolith without significant water or hydroxyl. [ISRO/NASA/JPL-Caltech/Brown]
Friday, September 25, 2009
Craters and a tell-tale signature of water
Many small, fresh craters bear signatures of water (H2O) and hydroxyl (OH)detected as absorption of IR in the range of 3 micrometers by NASA's Moon Mineralogy Mapper. Fig. A on left shows feldspar-rich terrain on the Moon's far side. The arrows point to the location of small, fresh craters. Fig. B on right indicates reflectance as a function of wavelength for the craters in Fig. A. The water and hydroxyl signature in these regions is seen as a characteristic dip in reflectance of IR near the 3-micrometer band, a region noted with a light-blue band. The dashed line shows background regolith without significant water or hydroxyl. [ISRO/NASA/JPL-Caltech/Brown]
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