Moon mineralogy mapper (M3)'s work proved that the moon is not completely dry but has some hydroxyl/water. M3’s data confirmed that the amount of hydroxyl on the lunar surface is inversely related to the measured signal brightness, suggesting the lunar surface is sensitive to temperature by solar insolation. We tested the effect of solar insolation on the local distribution of hydroxyl by using M3 data, and we found that most craters had more hydroxyl in shade areas than in sunlit areas. This means that the local distribution of hydroxyl is absolutely influenced by the amount of sunshine. We investigated the factors affecting differences in hydroxyl; we found that the higher the latitude, the larger the difference during daytime. We also measured the pyroxene content and found that pyroxene affects the amount of hydroxyl, but it does not affect the difference in hydroxyl between sunlit and shaded areas. Therefore, we confirmed that solar insolation plays a significant role in the local distribution of hydroxyl, regardless of surface composition.

1. INTRODUCTION
 2. DATA AND METHODS
 3. RESULTS AND DISCUSSION
  3.1 Hypothesis 1: More Hydroxyl is Distributed in Areaswith Less Solar Illumination
  3.2 Hypothesis 2: The Effects of Latitude on Hydroxyl areDifferent Between Sunlit and Shade Areas
  3.3 Hypothesis 3: The Pyroxene Content of the LunarSurface Affects the Difference in the Amount of Hydroxylin Shade and Sunlit Areas
  4. CONCLUSIONS
  ACKNOWLEDGMENTS
  REFERENCES

• Suyeon Kim(Department of Astronomy, Space Science and Geology, Chungnam National University)
• Yu Yi(Department of Astronomy, Space Science and Geology, Chungnam National University) Corresponding Author
• Ik-Seon Hong(Department of Astronomy, Space Science and Geology, Chungnam National University, Korea Astronomy and Space Science Institute)
• Jongdae Sohn(Korea Astronomy and Space Science Institute)