Five-O is a diverse group of investigators that view science questions from a broad range of perspectives and a diverse knowledge base. The interdisciplinary team is interconnect by four major themes.

Our four themes:

  1. Experiments and modeling: This theme will study regolith (soil) formation under extreme lunar conditions and investigate the origin(s) and evolution of polar ices.  Experiments and modeling will provide the insight necessary to accurately determine volatile source(s) by in-situ isotopic measurements. In addition, we will characterize physical, spectral, and chemical signatures of volatile ices, lunar minerals and glasses, and their interactions with each other under relevant conditions. 

Volatile Transport and Modification

The objective of this task is to experimentally determine differences in ejection probabilities for different isotopologues of water (H2O and HDO; where D is deuterium which is a hydrogen atom with a neutron) . The Astrophysical Isotopic Characterization Experimental (ICE) apparatus will be used to study the isotopic fractionation caused by volatile mobility. 

Laser Weathering

Remote sensing data indicate that polar regolith may have different physical, spectral, and chemical properties. This task will compare and contrast the properties of regolith (soil) synthesized in the laboratory under and polar (-200 degrees Fahrenheit and with volatiles) and equatorial (70 degrees Fahrenheit and dry) environments. Intense laser light is used in the experiment to simulate micrometeorite impacts.

Modeling transport effects on composition

Isotope compositions may evolve between the time of volatile delivery—by comet, solar wind, and volcanism—and the time of cold-trap capture of the volatile. This modeling task will simulate how transport and loss mechanisms affect isotopic composition (e.g., between isotopomers H2O and HDO).

Sample Alteration

In this task, we will search for evidence of mineralogical alteration in lunar rock and regolith samples. The planetary environment and analysis chamber (PEACh) will be used to examine the interaction of mineral and glass grains with ices as they undergo thermal excursions to warmer temperatures.

  1. Analytical Characterization of Volatile Exposed Materials will characterize samples from experiments and Interplanetary dust particles using: Electron microprobe, Scanning TEM, Secondary Ion Spectrometry nano FTIR, reflectance spectra from UV to NIR, magnetic properties, Laser Raman spectroscopy

to assess the sub-micron infrared spectroscopic changes (in absorption spectra and dielectric constant) in laboratory space-weathered materials produced

Transmission Electron Microscopy

Examples of edge electron energy loss spectra (EELS) at different core edges. Low-loss EELS is sensitive to water (bound/unbound) and other solar wind implantation products (H, He). (i) Low-loss features from (a-c) water (in a TEM wet cell) and (d-f) hydroxyl in talc [Mg3Si4O10(OH)2]. (ii) H-K and He-K edges in rims on H and He-irradiated silicate standards (from Bradley et al. 2014)

NanoSIMS measurements to measure water contents in FIB sections

  1. Remote Sensing—detection and quantification of organics and understanding the interplay of reflectance and thermal emission that confounds estimates of water abundance on the lunar surface.
  1. Sample Curation & Handling of cryogenic samples—will develop methodologies for maintaining, storing and handling pristine, sterile samples at cryogenic temperatures.