- Author, Georgina Rannard
- Role, Science reporter
Scientists have discovered a cave on the moon for the first time.
According to them, it could be an ideal place for people to build a permanent base as it is at least 100 meters deep.
According to the researchers, it is just one of probably hundreds of caves hidden in an “underground, unexplored world”.
Countries are racing to establish a permanent human presence on the Moon, but they must protect astronauts from radiation, extreme temperatures and space weather.
Helen Sharman, the first British astronaut to travel into space, told BBC News that the newly discovered cave seemed like a good place for a base, suggesting that humans could potentially live in the lunar caverns within 20 to 30 years.
But, she said, this cave is so deep that astronauts might have to rappel in and use “jetpacks or an elevator” to get out.
Lorenzo Bruzzone and Leonardo Carrer of the University of Trento in Italy discovered the cave by using radar to penetrate a hole in a rocky plain called the Mare Tranquillitatis.
It can be seen with the naked eye from Earth. This is also the spot where Apollo 11 landed in 1969.
The cave has a skylight on the lunar surface, leading to vertical and overhanging walls, and a sloping floor that may extend further underground.
It was formed millions or billions of years ago when lava flowed across the Moon, creating a tunnel through the rock.
The closest equivalent on Earth are the volcanic caves in Lanzarote, Spain, explains Professor Carrer, adding that the researchers visited these caves as part of their work.
“It’s really exciting. When you make these discoveries and look at these images, you realise you’re the first person in human history to see this,” said Prof Carrer.
Once Prof Bruzzone and Prof Carrer understood how large the cave was, they realised this could be a good site for a moon base.
“After all, life on Earth began in caves, so it makes sense that people could live in caves on the Moon,” says Prof. Carrer.
The cave has not yet been fully explored, but researchers hope to map it using ground radar, cameras or even robots.
Scientists first realized that there were likely caves on the moon about 50 years ago. Then, in 2010, a camera on a mission called the Lunar Reconnaissance Orbiter took pictures of pits that scientists thought might be cave entrances.
But researchers didn’t know how deep the caves were or whether they had collapsed.
The work of Prof Bruzzone and Prof Carrer has now answered that question, but much more needs to be done to understand the full extent of the cave.
“We have very good images of the surface – up to 25cm resolution – we can see the Apollo landing sites – but we know nothing about what lies beneath the surface. There are huge opportunities for discovery,” Francesco Sauro, coordinator of the European Space Agency’s Planetary Caves Topical Team, told BBC News.
The research could also help us explore caves on Mars in the future, he says.
That could open the door to evidence of life on Mars. If life were to exist, it would almost certainly be in caves on the planet’s surface, protected from the elements.
The Moon Cave may be useful to humans, but scientists also stress that it could answer fundamental questions about the history of the Moon and even our solar system.
The rocks in the cave are less damaged or eroded by space weather and form an extensive geological record dating back billions of years.
The research was published in the scientific journal Nature Astronomy.
Graphics by Gerry Fletcher