As humans consider living on the moon, Mars, and beyond, knowing how to find and use resources like water is essential.
Researchers from the University of California, San Diego, are helping by studying how to locate water on the moon. This information is important for future space missions like NASA’s Artemis campaign.
Nobel laureate Harold Urey and James Arnold, UC San Diego faculty members, were among the first to theorize that water exists on the moon, especially in the permanently shadowed regions of the poles. Scientists now believe moon water could come from three sources: being native to the moon, created by solar winds, or from icy comets.
Morgan Nunn Martinez studied lunar rocks from the 1969 Apollo 9 mission to learn about the origin of moon water. They found water in them by heating these rocks to 50, 150, and 1,000 degrees Celsius (122, 302, and 1,832 degrees Fahrenheit, respectively). The team analyzed the water’s oxygen isotopes to determine its origin.
At the lowest temperatures, lightly bound water molecules were released, which are weakly attached to the lunar rock. At 1,000 degrees Celsius, more deeply embedded and tightly bound water molecules were released.
This process collects and purifies gas water molecules to leave only oxygen. The team then measured the composition of three different oxygen isotopes.
Their research revealed that most lunar water likely comes from the moon itself or comet impacts rather than solar winds. This finding supports the idea that much of the moon’s water has been there for a long time, with more added by comet impacts.
Maxwell Thiemens said, “What’s nice about this research is that we’re using the most advanced scientific measurements, and it supports common sense ideas about lunar water — much of it has been there since the beginning, and these icy comet impacts added more. The more complicated method of solar wind-derived water doesn’t appear to have been that productive.”
The researchers also studied water samples from Mars, which could help NASA’s plans to colonize the moon and Mars. They found that Mars might have more water than the moon.
Finding water is just the first step. Extracting it in large enough quantities to sustain life will require more technological advancements.
Journal Reference:
- Maxwell Thiemens (Vrije Universiteit Brussel), Morgan Nunn Martinez and Mark Thiemens (UC San Diego). Triple oxygen isotopes of lunar water unveil indigenous and cometary heritage. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.232106912
