This story originally appeared in WIRED Italia and has been translated from Italian.
Their existence had been questioned for decades, but now we can finally say for sure: there are caves beneath the surface of the moon. This week, an international research team led by the University of Trento in Italy published a study Evidence of accessible areas beneath the lunar surface is shown in Nature Astronomy. The discovery could be crucial for the construction of future colonies on the Moon.
For more than half a century, astronomers have been theorizing about the existence of a network of caves and tunnels beneath the Moon’s surface. In 2009, a team of experts identified a deep hole on the lunar surface, supporting the hypothesis that underground caves may have formed on the Moon as a result of cooling lava beneath the surface. This week’s discovery proves the existence of longer underground conduits. “These structures had been hypothesized for more than 50 years, but this is the first time we have proven their existence,”“ says Lorenzo Bruzzone of the University of Trento, coordinator of the research.
To make this discovery, researchers reviewed data captured in 2010 by the radio frequency instrument aboard NASA’s Lunar Reconnaissance Orbiter, a spacecraft that has been orbiting the Moon since 2009, mapping its surface and searching for potential landing sites for future missions. Based on the images, researchers were able to reveal, hidden in the Sea of Tranquility region, an empty lava tube that could one day be accessible to astronauts.
“We analysed these images using complex signal processing technologies recently developed in our laboratory and discovered that part of the radar reflections from an area of the Sea of Tranquility can be attributed to an underground conduit,” says Bruzzone. “This discovery provides the first direct evidence of an accessible rock tunnel beneath the surface of the Moon.” Analysis of the data has also allowed researchers to build a model representing the initial part of the tunnel. “It is very likely that this is an emptied lava tube,” says Leonardo Carrer, a researcher at the University of Trento and first author of the article.
The findings could have important implications for future lunar missions. Meteorites and radiation make the lunar environment hostile to humans: cosmic and solar radiation is up to 150 times more potent than that experienced on Earth, and the threat from meteorites is continuous. Therefore, it is necessary to find protected areas for landing sites for probes or for the construction of long-term lunar infrastructure. Astronauts could therefore one day find shelter in these caves.