The southern polar region of the Moon is expected to be explored by NASA and other space agencies. Recent surveys of this region have shown an environment rich in volatile elements. Water ice has been detected in the permanently shadowed craters around the South Pole-Aitken Basin.
There are many theories about where the water came from, ranging from volcanic activity or solar wind to being delivered by comets. The water ice and volatiles in the crater were likely delivered by the comet that created it, according to a team of researchers from the U.S. and France.
The team was led by Dr. Kathleen Mandt. She was joined by colleagues from the Aix and the Southwest Research Institute in San Antonio, Texas. The paper about their research was published in the journal Nature Communications.
The implications of data obtained over a decade ago by LRO were reexamined for the sake of their study. Dr. Kurt Retherford is the principal investigator of LAMP.
“Water is considered an important resource because when you split water molecules, you end up with oxygen and hydrogen, critical components for breathable air and rocket fuel. The rest of the volatiles could be important resources, as well.”
The LCROSS and LRO were the first robotic lunar missions launched by NASA. Both were designed to gather data that would help inform future missions. NASA was planning on sending crewed missions to the Moon for the first time since the Apollo Era as part of the Constellation program. The Artemis Program followed the end of the Moon to Mars program.
The southern polar region was explored to find a potential lunar base site. The local presence of water ice in this cratered region made it attractive from an In-Situ Resource Utilization standpoint. In October 2009, the LRO and LCROSS missions explored the Cabeus crater to learn more about the origin and evolution of volatiles.
The spent upper stage of the LRO was used to impact the surface and send material into space. This was followed by the study of how the ejected volatiles were integrated into the ice. The LRO examined the material with the LAMP instrument, which was designed and overseen by the SwRI.
For more than a decade, LAMP has looked at the lunar surface for signs of ice and frost. The permanently-shadowed nature of the region and the fact that most of the water ice is located beneath the crater floors made this task difficult. By capturing the glowing hydrogen emissions of water, LAMP provided images that helped scientists characterize the distribution of water and other molecule on the Moon.
During the Apollo Era, there was a long-standing mystery about the Moon. Researchers noted the presence of water in samples of volcanic glass after examining Moon rocks returned by the Apollo astronauts. The water came from the Moon, despite the fact that it was contaminated. Scientists are trying to figure out where the water came from.
Scientists narrowed it down to three possibilities: volcanic outgassing, comet or micrometeoroid impacts, or surface chemistry initiated by solar wind particles. When the water was delivered and what quantities are implications of each of these possibilities. The team compared the volatiles to the potential sources for their study.
They focused on the abundances of four elements,hydrogen, nitrogen, oxygen, and sulfur, as they relate to carbon. The water ice and volatiles in the crater were delivered by the impactor that created it. Lizeth Maga is a recent graduate of the University of Texas at San Antonio-SwRI and is currently working at the JHUAPL.
“Based on the ratios measured and the composition of comets, such as Rosetta spacecraft measurements of Comet 67P, comets are likely the primary source of these volatiles. Impact gardening, a term referring to impacts that churn and enrich the uppermost regolith of moons and other airless bodies, is perhaps the next most important contributor for seeding the Cabeus crater with volatiles. With all the various sources to consider, ruling out the internal volcanic source with this study helps a lot.”
NASA will benefit from these results as they prepare to send astronauts back to the Moon, as well as other space agencies sending astronauts there for the first time. The lead author on the paper was Dr. Kathleen Mandt.
As humans prepare to return to the Moon, we have an unprecedented opportunity to make measurements in Cabeus and other PSRs to characterize the lunar volatiles as a function of depth. Expanding human exploration and understanding the history of the Earth-Moon system is supported by studying the potential lunar resources.
Nature Communication is read further.
All Rights Reserved © 2024
