Billions of years ago, a series of volcanic eruptions erupted on the Moon, covering hundreds of thousands of square miles of the orb’s surface in hot lava. Over the eons, that lava created the dark spots, or maria, that give the moon’s face its distinctive appearance today.
Now, new research from the University of Colorado Boulder (CU Boulder) suggests that volcanoes may have left another lasting effect on the moon’s surface: sheets of ice dot the moon’s poles and, in some places, can measure tens or even hundreds of feet. thick.
said Andrew Wilkowsky, lead author of the new study and a graduate student in the Department of Astrophysics and Planetary Science (APS) and the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder.
He and his colleagues published their findings this month in Planetary Science Journal.
Researchers have relied on computer models or simulations to try to recreate conditions on the Moon long before complex life appeared on Earth. They discovered that ancient lunar volcanoes spewed huge amounts of water vapor, which then settled on the surface forming stores of ice that may still be hiding in lunar craters. If any human being was alive at the time, they might have seen a piece of this frost near the boundary between day and night on the surface of the moon.
This is a potential bonus for future lunar explorers who will need water for drinking and processing into rocket fuel, said study co-author Paul Heine.
“It is possible that you have large ice layers under the surface at a depth of 5 or 10 meters,” said Hein, assistant professor at APS and LASP.
The new study adds to a growing body of evidence suggesting that the moon may be drowning in far more water than scientists previously thought. In a 2020 study, Heine and colleagues estimated that roughly 6,000 square miles of the moon’s surface could be able to trap and attach to ice — often near the moon’s north and south poles. Where all this water came from in the first place is unclear.
“There are a lot of potential sources right now,” Hein said.
Volcanoes can be large. The planetary scientist explained that 2-4 billion years ago, the Moon was a chaotic place. Tens of thousands of volcanoes erupted across its surface during this period, creating huge rivers and lakes of lava, unlike features you might see in Hawaii today – only more massive.
“They dwarf almost all blasts on Earth,” Hein said.
Recent research by scientists at the Lunar and Planetary Institute in Houston shows that these volcanoes also likely spew out towering clouds composed mostly of carbon monoxide and water vapor. These clouds then orbited around the moon, which could lead to the formation of thin, short-lived atmospheres.
That prompted Heine and Wilkowski to wonder: Could this same atmosphere leave ice on the moon’s surface, a bit like frost forming on Earth after a cold fall night?
To find out, the duo, along with LASP research assistant Margaret Landis, set out to try to position themselves on the moon billions of years ago.
The team used estimates that at its peak, the moon experienced an average of one volcanic eruption every 22,000 years. The researchers then tracked how the volcanic gases could orbit the moon and escape into space over time. They discovered that conditions may have become icy.
According to the group’s estimates, about 41% of the water may have condensed from volcanoes on the Moon as ice.
“The atmosphere has been escaping for more than 1,000 years, so there was plenty of time for ice to form,” Wilkowski said.
There was probably so much ice on the Moon, in fact, that you could, probably, spot frost gleams and thick polar ice caps from Earth. The group calculated that about 18 quadrillion pounds of volcanic water could condense as ice during that time. That’s more than the water currently in Lake Michigan. The research indicates that much of that lunar water may still be present today.
However, it will not be easy to find ice cubes in space. Most of this ice likely accumulated near the moon’s polishes and may be buried under several feet of lunar dust or regolith.
Hein said there’s another reason people or robots come back and start digging.
“We really need to go deeper and look for it,” he said.
Reference: “Polar Ice Build-up from Volcano-Induced Transient Atmosphere on the Moon” by Andrew X. Wilkowsky, Paul Heine and Margaret E. Landis, May 3, 2022, Available here. Planetary Science Journal.
DOI: 10.3847 / PSJ / ac649c