You’re the expert lunar geologist of the first Moon cave exploration mission, currently hoisted up by a rope off the edge of a lunar cave. Probes were sent in advance and deemed the cave as safe. You are in a deep lava tube tunnel in an area of the Moon named “Mare Tranquillitatis.” The “Sea of Tranquility” is an area on the surface of the Moon, which can be seen on its near side, the side we always see. A dark area such as this one is called a maria. The darkened surface being from its richness of basalt, an igneous rock, which means it comes from once-existing lava flows, cooling and solidifying in the process. It was believed by early astronomers that these dark areas were actual lunar seas, the word maria being Latin for sea. The cave you are now descending into was created by ancient lava flows, forming tunnels 2 billion years ago. The Moon is now dead, though, similar to an asteroid, ancient because the lava flows have long gone.
You place your right hand on the rope, currently anchored up off an electric winch, powered by solar-chargeable batteries. If the winch fails, and you fall, flashes in your mind for a moment, but you distract yourself hastily. You look up to your colleague in the matching space suit positioned above you. You wave him off; he gives you one back and disappears out of your field of view, off the edge of the tunnel you are making your way into. You are lowered further into the cave. Only a staggering 328 feet down, and you’ll make contact with the bottom of the lunar skylight.
You hear your partner on the radio. “You doin’ alright, bud?” he asks. You aim your flashlight down in the abyss below and the bottom comes into view. Rocks the size of cars, scattered on the bottom. The view is suffocating and spectacular at the same time. After a few daunting minutes, you finally make your way to the bottom, quickly loosening the anchor completely on your harness. As you reposition your eyes, you look ahead, deep into a cave smaller than the one you’re already in. It goes on for a couple of yards and shoots to the right. The walls of this cave feel a little closer now, but it’s just your uneasiness rearing its head. After making your way straight promptly, you slowly take the right, you then feel a familiar surface, a surface familiar to you during your time in Alaska as that research assistant. It’s slippery and you quickly lose your footing, falling back. But because of the Moon’s gravity, you fall in literal slow motion, thankfully catching yourself in the process.
Looking down, you see a surface that glistens as the light pours out of your helmet’s flashlight. You have found something amazing: ice water in the lunar caves of the Moon. This find to you was already expected, of course, since the SOFIA mission from 2020 proved that there was ice water on the Moon. The fact that you didn’t practice more caution due to ice being known already is a mystery to you; you chalk it up to the excitement getting the best of you.
You continue your journey onward into the cave, now descending deeper into the lunar crust. Yards upon yards you descend, and you’re starting to think you may never hit the bottom. The light shows to you that the tunnel is starting to bottom out. You make your way down to a cave larger than the one you were just in. It’s magnificent, the walls of this cave towering over you in all directions. The ceiling, high above you, is covered in ice. After taking in the view, you then ascend an embankment. Something then comes into view. It’s even more awe-inducing than that ice you slipped on earlier: a lake inside of the Moon. It’s apparent to you that this is due to a number of things. First, this water most likely comes from ancient comet impacts. Second, this cave is warmer and more pressurized. And, lastly, the cave works as a case to keep the liquid water from escaping into space. You quickly radio your crew mates, “I have found a lake of liquid water inside the Moon.”
Although the story I just told above has never happened, and most likely would not happen in such a way, the train of thought is a fun one to go down, nonetheless. What stands true is that there is a real possibility that subterranean lakes exist in the Moon. The Lunar Prospector spacecraft proved one thing to us, it being that there’s a possiblity that ice water could be found on the Permanently Shadowed Regions (PSRs) of the Moon, areas that never get any sunlight, literally none. A desolate cold wasteland. It was later proved that there was indeed ice water in the PSRs.
The 2020 mission, named SOPHIA, found actual water molecules on even sunlit areas of the Moon. The total amount, a cubic meter in a crater the size of 140 miles, spread across the lunar surface, shows enough water molecules to fill a 12 oz. water bottle, roughly. An amount of water that is 100 times less than the Sahara Desert. In a research paper of the name “Subterranean Lakes on the Moon: Liquid Water Beneath the Ice,” by Andreas Hein, Manasvi Lingam, Marshall Eubanks, and William Paul Blase, it discusses the possibility of liquid water beneath the lunar surface. Underneath the icy regions of the Moon, never touched by sunlight. A staggering amount of ice that weighs equal to 1.3 trillion pounds, although recent studies show that possibly the amount was overestimated. Nonetheless, the Moon’s PSRs contain a lot of ice water.
As for the further exploration of the Moon, we have Artemis II to look forward to, projected to occur in September of 2025. This mission will have a crew go around the Moon. While Artemis III, in September of 2026, will have the first astronauts land near the lunar South Pole. It is my hope that this will aid us in further understanding of the Moon and its rich history. As for lunar cave exploration, currently the European Space Agency Concurrent Design Facility is creating a probe prototype named “Daedalus,” which will be lowered into a lunar cave using a tether. After being lowered it will then disconnect from the tether and roll away autonomously to explore. The tether that Daedalus was brought down with will double as a Wi-Fi receiver, allowing it to send back its findings. The mission will hope to find areas in these tunnels where radiation and temperature are stable. What this means is that we will be one step closer to having astronauts permanently on the Moon.
Between this and the possible water in the caves, the future of Moon exploration is looking very interesting.
