|Three articles in Science Express were released yesterday, 24 September. They detail evidence for water from three different Lunar missions:
These are summarized by A Lunar Waterworld by Paul G. Lucey at Hawaii Institute of Geophysics and Planetology, University of Hawaii, 1680 East West Road, POST 504, Honolulu, HI 96822, USA.
“Space-based spectroscopic measurements provide strong evidence for water on the surface of the Moon.”
The authors and abstracts are detailed below:
Credit: NASA Image
- Temporal and Spatial Variability of Lunar Hydration as Observed by the Deep Impact Spacecraft by Jessica M. Sunshine (1*), Tony L. Farnham (1), Lori M. Feaga (1), Olivier Groussin (2), Frédéric Merlin (1), Ralph E. Milliken (3), Michael F. A’Hearn (1)
1 University of Maryland, College Park, MD, USA.
2 Laboratoire d’Astrophysique de Marseille, Marseille, France.
3 Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA.
“The Moon is generally anhydrous, yet the Deep Impact spacecraft found the entire surface to be hydrated during some portions of the day. OH and H2O absorptions in the near infrared were strongest near the North Pole and are consistent with <0.5 wt% H2O. Hydration varied with temperature, rather than cumulative solar radiation, but no inherent absorptivity differences with composition were observed. However, comparisons between data collected one week (a quarter lunar day) apart show a dynamic process with diurnal changes in hydration that were greater for mare basalts (~70%) than for highlands (~50%). This hydration loss and return to steady state occurred entirely between local morning and evening, requiring a ready daytime source of water group ions, which is consistent with a solar wind origin.”
- Character and Spatial Distribution of OH/H2O on the Surface of the Moon Seen by M3 on Chandrayaan-1
C. M. Pieters 1*, J. N. Goswami 2, R. N. Clark 3, M. Annadurai 4, J. Boardman 5, B. Buratti 6, J.-P. Combe 7, M. D. Dyar 8, R. Green 6, J. W. Head 1, C. Hibbitts 9, M. Hicks 6, P. Isaacson 1, R. Klima 1, G. Kramer 7, S. Kumar 10, E. Livo 3, S. Lundeen 6, E. Malaret 11, T. McCord 7, J. Mustard 1, J. Nettles 1, N. Petro 12, C. Runyon 13, M. Staid 14, J. Sunshine 15, L. A. Taylor 16, S. Tompkins 17, P. Varanasi 6
1 Brown University, Providence, RI 02912, USA.
2 Physical Research Laboratory, Ahmedabad, India.; Indian Space Research Organization, Bangalore, India.
3 U.S. Geological Survey, Denver, CO 80225, USA.
4 Indian Space Research Organization, Bangalore, India.
5 Analytical Imaging and Geophysics, Boulder, CO 80303, USA.
6 Jet Propulsion Laboratory, Pasadena, CA 91109, USA.
7 Bear Fight Center, Winthrop, WA 98862,USA.
8 Mt. Holyoke College, South Hadley, MA 01075, USA.
9 Applied Physics Laboratory, Laurel, MD 20723–6005, USA.
10 National Remote Sensing Agency, Hyderabad, India.
11 Applied Coherent Technology Corporation, Herndon, VA 22070, USA.
12 NASA Goddard, Greenbelt, MD 20771, USA.
13 College of Charleston, Charleston, SC 29424, USA.
14 Planetary Science Institute, Tucson, AZ 85719–2395, USA.
15 University of Maryland, College Park, MD 20742, USA.
16 University of Tennessee, Knoxville, TN 37996–1410, USA.
17 Defense Advanced Research Projects Agency, Arlington, VA 22203, USA.
“The search for water on the surface of the anhydrous Moon remained an unfulfilled quest for 40 years. The Moon Mineralogy Mapper (M3) on Chandrayaan-1 has now detected absorption features near 2.8-3.0 µm on the surface of the Moon. For silicate bodies, such features are typically attributed to OH- and/or H2O-bearing materials. On the Moon, the feature is seen as a widely distributed absorption that appears strongest at cooler high latitudes and at several fresh feldspathic craters. The general lack of correlation of this feature in sunlit M3 data with neutron spectrometer H abundance data suggests that the formation and retention of OH and H2O is an ongoing surficial process. OH/H2O production processes may feed polar cold traps and make the lunar regolith a candidate source of volatiles for human exploration.”
- Detection of Adsorbed Water and Hydroxyl on the Moon by Roger N. Clark from U.S. Geological Survey, MS 964, Box 25046 Federal Center, Denver, CO 80227, USA.
“Data from the Visual and Infrared Mapping Spectrometer (VIMS) on Cassini during its fly-by of the Moon in 1999 show a broad absorption at 3µm due to adsorbed water and near 2.8µm attributed to hydroxyl in the sunlit surface on the Moon. The amounts of water indicated in the spectra depend on the type of mixing, and the grain sizes in the rocks and soils but could be 10 to 1,000 parts per million and locally higher. Water in the polar regions may be water that has migrated to the colder environments there. Trace hydroxyl is observed in the anorthositic highlands at lower latitudes.”