Scientists confirm underground “tunnel” near Apollo 11 landing site

Scientists have confirmed the existence of an underground tunnel-like feature near the Apollo 11 landing site on the Moon, ending nearly 50 years of speculation about subsurface caves.

The discovery, led by researchers from the University of Trento in Italy, identified a lava tube cave beneath the Mare Tranquillitatis, or “Sea of Tranquility,” where astronauts Neil Armstrong and Buzz Aldrin first set foot in 1969.

This significant finding, published in Nature Astronomy, was made using data from NASA’s Lunar Reconnaissance Orbiter (LRO). The tunnel-like feature provides new insights into the Moon’s geological composition and offers potential shelter for astronauts on future missions.

Lorenzo Bruzzone, a professor at the University of Trento, emphasized the importance of this discovery, noting that the existence of such underground features had been theorized for over half a century but never confirmed until now.

The team reexamined data from the Miniature Radio-Frequency (Mini-RF) instrument aboard the LRO, originally obtained in 2010, which included radar reflections from a pit in Mare Tranquillitatis.

Leonardo Carrer, another researcher from the University of Trento, explained that the team was able to model a section of the conduit, concluding that it is most likely an empty lava tube.

Such features could serve as ideal shelters for astronauts, offering protection from extreme temperatures, cosmic and solar radiation, and meteorite impacts.

The Moon’s surface temperatures can reach 127°C on the sunlit side and plunge to -173°C on the dark side. Lava tube caves could provide a stable environment for astronauts, shielding them from these harsh conditions.

Additionally, these caves would offer protection from radiation, which is up to 150 times more intense on the Moon than on Earth, and from meteorite impacts, which have created the Moon’s characteristic craters.

Wes Patterson, principal investigator for the Mini-RF based at the Johns Hopkins Applied Physics Laboratory, said the team’s findings demonstrate “both how radar data of the Moon can be used in novel ways to address fundamental questions for science and exploration and how crucial it is to continue collecting remotely sensed data of the Moon.”

“This includes the current LRO mission and, hopefully, future orbiter missions,” Patterson said.

The discovery is published in a new study, “Radar evidence of an accessible cave conduit on the Moon below the Mare Tranquillitatis pit,” in Nature Astronomy.