Credit: ISS/NASA

A new study adds to a growing body of evidence suggesting that the Moon may be a waterlogged world, far more than scientists once thought.

This prospective finding stems from work done by University of Colorado, Boulder researchers that suggests lunar volcanoes may have left another lasting impact on the Moon’s surface: sheets of ice that dot the Moon’s poles and, in some places, could measure dozens or even hundreds of feet thick.

“We envision it as a frost on the Moon that built up over time,” said Andrew Wilcoski, lead author of the new study and a graduate student in the Department of Astrophysical and Planetary Sciences (APS) and the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder.

Wilcoski and his colleagues — Paul Hayne and Margaret Landis — published their findings this month in The Planetary Science Journal.

Credit: Andrew X. Wilcoski et al 2022 Planet. Sci. J. 3 99

Short-lived, collisional atmospheres

“Our work suggests that the volcanically active period of the early Moon would have been punctuated by short-lived, collisional atmospheres that enabled the efficient sequestration of large quantities (8.2 × 1015 kg) of water ice at the poles and the temporary diurnal availability of water ice and vapor at all latitudes,” states the research paper.

“It’s possible that 5 or 10 meters below the surface, you have big sheets of ice,” added Hayne, assistant professor in APS and LASP in a university press statement.

At its peak, the Moon is estimated to have experienced one eruption every 22,000 years, on average. The research team used computer modeling to track how volcanic gases may have swirled around the Moon, escaping into space over time. The result: conditions may have gotten icy; roughly 41% of the water from volcanoes may have condensed onto the Moon as ice, estimated the scientists.

Maximum surface temperatures measured by the Diviner Lunar Radiometer Experiment and adjusted to account for ∼25% lower solar luminosity at ∼3.5 Ga from ±60° latitude to the poles in the south (left) and the north (right).
Credit: Andrew X. Wilcoski et al 2022 Planet. Sci. J. 3 99

Subsurface burial grounds

As an input, the model uses maximum temperature maps from the Diviner Lunar Radiometer Experiment on board the NASA Lunar Reconnaissance Orbiter.

Ice distribution and thickness after a complete 2 Gyr model run. (a, b) Maps from ±60° latitude to the poles in (a) the south and (b) the north. (c, d) Maps from ±80° latitude to the poles in (c) the south and (d) the north. (e, f) Ice deposits remaining after 4 Gyr of sublimation to space.
Credit: Andrew X. Wilcoski et al 2022 Planet. Sci. J. 3 99

The group calculated that about 18 quadrillion pounds of volcanic water could have condensed as ice during that period. That’s more water than currently sits in Lake Michigan. And the research suggests that much of that lunar water may still be present today, but buried under several feet of lunar dust, or regolith, explains the university press statement.

To get down to this ice reservoir, that means drill, baby drill.

Next step

But first, what next?

“One of the next steps for this particular project will be determining what other substances may have condensed out of these volcanic atmospheres and how much of these substances we might expect to find mixed in with volcanically sourced ice,” Wilcoski told Inside Outer Space.

For example, various sulfur species were likely released during volcanic eruptions on the Moon and many may have ended up mixed in with the water ice, Wilcoski said. “It’s important to nail down how much sulfur we’d expect to find in these ice deposits because if we one day drill into this ice and find sulfur then we will be able to tell how much of that ice came from volcanism as opposed to other sources. Additionally, if this ice is one day used as a resource by humans, it’s important to know what else is mixed in with the water.”

Wilcoski added that a longer-term next step that goes beyond just he and his colleagues work is to one day go drill for this ice on the Moon.

“With our work, we’ve shown that it’s possible that volcanism left a significant amount of ice at the lunar poles. If we can find the remnants of these deposits on the Moon today, they will tell a fascinating story of the history of water on the Moon and in our solar system,” Wilcoski concluded.

To access the research paper – “Polar Ice Accumulation from Volcanically Induced Transient Atmospheres on the Moon” – go to:

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