Planetary Society logo
  • “Exploration is in our nature.” - Carl Sagan

Lunar water abundances change with time of day

Lunar water abundances change with time of day
Lunar water abundances change with time of day Observations from Deep Impact's HRI-IR Spectrometer on June 2 and 9, 2009 -- one week or one quarter of a lunar day apart -- reveal changes in the amounts of water and hydroxyl molecules present in the lunar soil. "H" and "M" indicate the locations of the same spot of Highland and Mare material in the two observations. The top right graph shows the signal in the highland unit near noon (red) and evening (blue): the absorption feature due to water was much stronger in the evening than at noon. NASA / JPL-Caltech / UMD