On Oct. 26, NASA announced that water exists in far greater abundance on the sunlit side of the moon than had hitherto been believed. The discovery resulted from observations of a telescope that NASA regularly flies at an altitude of 45,000 feet above the Earth’s surface.
NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) confirmed the finding, which is indicative that water may be found across the lunar surface — not just cold, shadowed places.
Evidence of water molecules were found in the Clavius Crater, which is the one that is visible from Earth.
The discovery has both scientists and advocates of a return to the moon excited, to say the least. The former are speculating about how the water is getting to the moon’s surface under the blaze of sunlight.
There are several theories about how water might have arrived on Earth’s only natural satellite, including that micrometeorites that have rained down on the Moon’s surface might have deposited the water upon impact. Or, perhaps the hydrogen carried from the Sun’s solar wind interacts with oxygen minerals in the soil, creating hydroxyl.
Scientists also wonder how the water accumulates and is stored.
Besides the fact that SOFIA will be tasked with imaging other areas of the moon to find deposits of water, the practical results of the discovery are, as yet, unclear. NASA, as Space News notes, is not changing its objective to landing near the South Pole of the moon and eventually establishing a base there. Immense amounts of water ice exist in that region in permanently darkened craters. The South Pole also features highlands that are bathed in sunlight, perfect for building solar power collectors.
What the discovery of water on the sunlit side of the moon means in practical terms is a question that has yet to be answered. Does it exist across the lunar surface? If so, in what quantities? Finally, can the water be extracted in amounts that can be useful for future lunar explorers?
When the first Apollo astronauts walked on the moon, the conventional wisdom was that Earth’s nearest neighbor was bone dry. That belief was one of the reasons that humans stopped going to the moon in 1972 and have not been back since.
All that began to change when the Clementine probe, ironically not a NASA mission but one mounted in support of the Strategic Defense Initiative, first found indication of water ice at the lunar poles. Subsequent missions, both by NASA and by international space agencies such as the Chandrayaan-1, launched by the India Space Research Organization, confirmed the existence of the precious water ice. The late Dr. Paul Spudis, who worked in one capacity or another on many of these robotic missions, was the first to understand the implications of water on the moon and how it could further lunar exploration, not to mention for voyages deeper into space.
The moon is the repository of a great many resources, enough that it could become the basis of a space-based industrial revolution. But the water will be the resource that will make everything possible. Water can be drunk and can be used for agriculture. Water can be refined into rocket fuel, making the moon into a refueling stop for spacecraft headed deeper into the solar system, to Mars and beyond. Water on the moon is more precious than gold. It will ensure that life beyond the confines of Earth is possible.
Mark Whittington, who writes frequently about space and politics, has published a political study of space exploration entitled Why is It So Hard to Go Back to the Moon? as well as “The Moon, Mars and Beyond.” He blogs at Curmudgeons Corner. He is published in the Wall Street Journal, Forbes, The Hill, USA Today, the LA Times, and the Washington Post, among other venues.