Scientists have discovered a cave on the Moon for the first time. They believe this cave, which is at least 100 meters deep, could be a perfect spot for humans to build a permanent base. These caves could serve as the foundation for a moonbase or an emergency lunar shelter. Inside, the temperature remains relatively stable, and astronauts would be naturally protected from harmful cosmic rays, solar radiation, and micrometeorites.
Researchers say this cave is just one of probably hundreds of hidden caves in an "underground, undiscovered world." As countries compete to establish a lasting human presence on the Moon, they will need to protect astronauts from radiation, extreme temperatures, and space weather. However, she mentioned that the cave is so deep that astronauts might need to climb down with ropes and use "jet packs or a lift" to get back up.
Lorenzo Bruzzone and Leonardo Carrer from the University of Trento in Italy discovered the cave by using radar to explore the entrance of a pit on a rocky plain known as the Mare Tranquillitatis.
Analysis of radar data from NASA's Lunar Reconnaissance Orbiter (LRO) showed that the Mare Tranquillitatis pit, the deepest known pit on the Moon, connects to a cave that is 45 meters wide and up to 80 meters long—about the size of 14 tennis courts. This cave is located around 150 meters below the surface.
The cave can be seen from Earth with the naked eye and is located near the Apollo 11 landing site from 1969. The cave has a skylight on the moon's surface and an opening that leads down to walls that go straight down and hang over the space below. It formed millions or billions of years ago when lava flowed on the Moon, creating a tunnel through the rock.
Prof. Carrer explains that the closest equivalent on Earth would be the volcanic caves in Lanzarote, Spain. He adds that the researchers visited those caves as part of their study.
At least 200 pits have been identified on the Moon, and many of those found in lava fields might lead to large underground lava tubes. "The main benefit of caves is that they provide the essential structural components for a potential human base without the need for complex construction," said Leonardo Carrer, the study's lead author.
A lava tube is a natural tunnel created by flowing lava beneath the hardened surface of a lava flow. As the surface lava cools and solidifies, the molten lava underneath keeps moving, eventually draining away and leaving a hollow, tube-shaped tunnel. These tubes can be found on Earth, the Moon, and Mars, and can vary in size.
"It's really exciting. When you make these discoveries and see these images, you realize you're the first person in history to see them," said Prof. Carrer. When Prof. Bruzzone and Prof. Carrer saw how large the cave was, they thought it could be a great place for a lunar base. "After all, life on Earth started in caves, so it makes sense that we could live in them on the Moon," says Prof. Carrer.
The cave hasn't been fully explored yet, but researchers hope to use ground-penetrating radar, cameras, or even robots to map it. Scientists suspected there might be caves on the Moon about 50 years ago. In 2010, a camera on the Lunar Reconnaissance Orbiter mission took pictures of pits that scientists believed could be cave entrances. However, researchers were unsure how deep the caves were or if they had collapsed.
Thanks to the work of Prof. Bruzzone and Prof. Carrer, we now have answers to these questions, but there is still a lot more to learn about the full size of the cave. "We have excellent images of the surface with up to 25cm resolution. We can even see the Apollo landing sites, but we know nothing about what is beneath the surface. There are great opportunities for discovery," Francesco Sauro, Coordinator of the Topical Team Planetary Caves of the European Space Agency, told BBC News.
He says the research could also help us explore caves on Mars in the future. This could lead to finding evidence of life on Mars since any life that existed would likely have been sheltered inside caves, away from the harsh conditions on the planet's surface.
The Moon cave could be beneficial for humans, but scientists also emphasize that it might help answer important questions about the Moon's history and even our solar system. The rocks inside the cave are less affected by space weather, so they can offer a detailed geological record that goes back billions of years.
Lunar cave systems are considered excellent locations for future crewed bases because the thick rock ceiling can protect people and infrastructure from the extreme temperature changes on the lunar surface and from high-energy radiation," said Katherine Joy, a professor of Earth sciences at the University of Manchester. "However, we still know very little about the underground structures beneath these pit entrances."
This research is published in the scientific journal Nature Astronomy.
(The author of this article is a Defence, Aerospace & Political Analyst based in Bengaluru. He is also Director of ADD Engineering Components, India, Pvt. Ltd, a subsidiary of ADD Engineering GmbH, Germany. You can reach him at: girishlinganna@gmail.com)
(The views expressed are the authors own and do not reflect that of DNA).