- author, Georgina Ranard
- Role, Science Correspondent
Scientists have discovered a cave on the moon for the first time.
At a depth of at least 100 metres, this could be an ideal place to build a permanent base for humans, they say.
This cave is just one of hundreds hidden in an “undiscovered underground world,” according to researchers.
Countries are racing to establish a permanent human presence on the Moon, but they will need to protect astronauts from radiation, extreme temperatures, and space weather.
Britain’s first female astronaut, Helen Sharman, told BBC News that the newly discovered cave looked like a good place to set up a base, and suggested that humans might be able to live in lunar craters within 20 to 30 years.
But she said the cave is so deep that astronauts may have to rappel down and use “jet packs or an elevator” to get out.
Lorenzo Bruzzone and Leonardo Carrer of the University of Trento in Italy were able to discover the cave using radar to penetrate the opening of a pit in a rocky plain called the Sea of Tranquility.
It can be seen with the naked eye from Earth, and is also where Apollo 11 landed in 1969.
The cave contains a skylight on the moon’s surface, leading to overhanging vertical walls, and a sloping floor that may extend far below ground.
They were formed millions or billions of years ago when lava flowed onto the moon, creating a tunnel through the rock.
The closest equivalent on Earth is the volcanic caves in Lanzarote, Spain, Professor Carrer explains, adding that the researchers visited those caves as part of their work.
“It’s really exciting,” said Professor Carrier. “When you make these discoveries and look at these images, you realise that you are the first person in human history to see this.”
Once Professor Bruzon and Professor Carrier realized how large the cave was, they realized it might be a good place to set up a lunar base.
“After all, life on Earth began in caves, so it makes sense that humans could live in them on the Moon,” says Professor Carrier.
The cave has not yet been fully explored, but researchers hope to use ground-penetrating radar, cameras or even robots to map it.
Scientists first became aware of caves on the moon about 50 years ago. Then in 2010, a camera on a mission called the Lunar Reconnaissance Orbiter took pictures of craters that scientists thought might be cave entrances.
But researchers did not know how deep the caves were, or whether they would collapse.
The work of Professor Bruson and Professor Carrier has now answered this question, although much remains to be done to understand the full extent of the cave.
“We have very good images of the surface – down to 25cm resolution – and 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 team, told BBC News.
He says the research could also help us explore caves on Mars in the future.
This could open the door to finding evidence of life on Mars, because if it did exist, it would certainly have been inside caves protected from the elements on the planet’s surface.
The Moon Cave may be useful to humans, but scientists also say it could help answer fundamental questions about the history of the moon, and even our solar system.
The rocks inside the cave will not be damaged or eroded by space weather, so they can provide a broad geological record going back billions of years.
The research was published in the scientific journal Nature Astronomy.
Chart by Jerry Fletcher
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