The next topic suggested by A Brief History of the Future is the idea of a moon base underground.
On the Moon, a permanent base was set up in lava tubes close to the South Pole. Here they had light for their solar power arrays and frozen ice to supply the base with water. Being underground protected them from the temperature extremes on the surface and the airtight tunnels meant that residents needed neither suits nor helmets.
To my surprise, this is exactly what NASA and other space organisations are planning.
 |
| Lava Beds National Monument, California |
Lava tubes are a phenomenon on Earth too. When lava forces its way to the surface, the outside of the flow cools faster than the inside. This creates a tube which, when the lava stops flowing, may drain and leave a strong tunnel. Lava Beds National Monument in California has a great many lava tubes which are being explored as preparation for Moon occupation.
 |
| Lava Tube, Vidgelmir |
Some tunnels are too near to the surface and can collapse, and astronomers have identified locations on the Moon which look like collapsed tunnels and pits which could be openings into tunnels. Some of these tunnels appear to be huge – more than a kilometre wide and many kilometres long. Large enough to contain a whole city.
It is not just saving the labour of building a habitat, the Moon has no atmosphere to protect the surface against radiation. No astronaut has so far spent more than three days on the surface, their suits are not enough to protect them. The Moon’s surface is also subject to meteorites, some of which can be very large.
And there is also the question of resources. The more that can be found on the Moon, the less they need to take with them. Water ice has been found in permanently-shaded locations, and may well be found in quantity in lava tubes. Scientists are working on ways of mapping lava tubes from the surface, to find out how big they are, how far they spread, and if there is a lot of rubble. This would save exploration which would be time consuming and dangerous.
Here are two articles from the Space.com website you might find interesting:
Are Moon Caves Safe for Astronauts? Earth’s Lava Tubes Can Help Us Find Out
Living Underground on the Moon: How Lava Tubes Could Aid Lunar Colonization
Ann Marie Thomas is the author of four medieval history books, a surprisingly cheerful poetry collection about her 2010 stroke, and the science fiction series Flight of the Kestrel. Book one, Intruders, and book two Alien Secrets, are out now. Follow her at http://eepurl.com/bbOsyz