The South Pole of the Moon is filled with craters that contain ice, but for years there’s been a debate in the scientific community as to when and where water first appeared on the lunar surface.
Now, however, researchers are saying that the pockets of ice we see on the Moon today are likely the result of multiple events that “rained down ancient water-bearing objects,” according to an informative new article from IFL Science:
“To determine the age of the ice, researchers first aged 20 craters found at the lunar south pole using data from NASA’s Lunar Reconnaissance Orbiter (LRO), which has been orbiting and collecting images of the moon for the last decade. Older craters showed more signs of wear around the edges, as well as pockmarks from asteroids or comets that may have struck the surface over time.”
Ariel Deutsch, a graduate student at Brown University’s Department of Earth, Environmental and Planetary Sciences who is also the lead author of a new study noted that the age of the ice on the Moon enables scientists to better understand the original source of the water that later froze:
“The ages of these deposits can potentially tell us something about the origin of the ice, which helps us understand the sources and distribution of water in the inner solar system. For exploration purposes, we need to understand the lateral and vertical distributions of these deposits to figure out how best to access them. These distributions evolve with time, so having an idea of the age is important.”
Most of the ice that has been located on the Moon is in craters that formed at least 3 billion years ago. But some of the ice is newer, and that suggests that it was deposited at another time entirely:
“In these older, larger craters, the ice was also patchy due to bombardments from asteroids and comets over time. Newer, smoother ice was found in more recent craters as well. It’s believed that this young ice might have made its way to the moon in a different way than the old ice.
“And if the ice is, in fact, different ages, then it means it likely came from two different sources.”
That raises an important question: How did the ice get there if it was deposited at different times? Turns out there’s a theory for that, too.
When the Moon was young, scientists say, it was struck by “relatively high impact rates of comets and asteroids,” each of which contained ice and water. That would explain the older ice that has been found on the surface. The younger ice, however, probably arrived via “micrometeorites or through interactions with the solar wind.”
The only way to know for certain, according to co-author Jim Head, is to collect more samples from the moon:
“When we think about sending humans back to the Moon for long-term exploration, we need to know what resources are there that we can count on, and we currently don’t know. Studies like this one help us make predictions about where we need to go to answer those questions.”
NASA’s Artemis program is sending a man and woman to the Moon within the next five years, and that could well provide new data that will help us better understand our Moon and what both its past and future means for Earth, too.
Here’s more on the ice discovered on the lunar surface:
Featured Image Via JPL/NASA