Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9PYTS 395B – Detecting Ice on the Moon1Mercury (and the Moon) possesses a tenuous atmosphereCalcium now also seen at MercurySodium emission at the Moon and Mercury shows temporal changesStirring of regolith by small impactsPYTS 395B – Detecting Ice on the Moon2Evidence for ice in polar craters of MercuryEvidence for ice at lunar polesClementine bi-static radar Lunar prospector neutronEvidence for ice at poles of MercuryVLA radar returnsSungrazing cometsKreutz groupSource of water?PYTS 395B – Detecting Ice on the Moon3PYTS 395B – Detecting Ice on the Moon4Feldman et al., 1998PYTS 395B – Detecting Ice on the Moon5Bussey et al., 1999PYTS 395B – Detecting Ice on the Moon6Margot et al., 1999PYTS 395B – Detecting Ice on the Moon7Modeling (Vasavada et al. 1999) shows temperatures in permanently shadowed craters are very lowThese cold traps are favored condensation sitesVasavada et al., 1999PYTS 395B – Detecting Ice on the Moon8Water leaves cold traps by sublimation5-15% returns on Mercury20-50% returns on the MoonThe rest is lostWater can be delivered by meteors and cometsFor Mercury these rates have been estimatedBalance exists if Tice is ~113KKillen et al., 1997PYTS 395B – Detecting Ice on the Moon9Lunar cold traps dry compared to MercuryRecent comet impact?Polar inconsistency?More H in lunar north poleMore permanent shadows in lunar south poleBurial depth differencesDispersed
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