Returning humans to the lunar surface presents an unprecedented opportunity to determine the origin of volatiles stored in the permanently shaded regions (PSRs) of the Moon.
In 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) experiment impacted the upper stage of a spent Centaur rocket into the PSR of Cabeus crater, creating a plume that contained the first carbon-, nitrogen-, and sulfur bearing volatiles detected in the lunar PSRs. These ground-breaking observations not only provided ground truth for ongoing remote observations of water on the lunar surface but also vital clues to the origin of volatiles present on the Moon.
So far, the source of the volatiles sampled by the LCROSS plume has remained undetermined. To determine the origin of these volatiles researchers had to account for how volatile composition may have changed between the source, storage in the PSR, and release into the plume. Several processes occurred between initial delivery by the source and detection in the plume that may have changed the molecular composition. This means that species that were measured in the plume may not be the same as the molecular species found in the source.
In this new study published in Nature, researchers simplified the analysis and eliminated as many influences as possible. Instead of using molecular composition they compared the elemental composition of the LCROSS volatiles with the elemental composition of the potential sources, evaluating abundances of four elements as they relate to carbon: hydrogen (C/H), nitrogen (N/C), oxygen (O/C), and sulfur (C/S). Through this analysis they determined that the volatiles sampled by LCROSS are not volcanic in origin, and are best explained by cometary impacts.
For more read the full paper here.
Posted by: Soderman/SSERVI Staff
Source: SSERVI RESOURCE Team