Moon's Huge Lava Tubes Perfect For Heinlein's Bat Wings

Lava tubes on Earth, in California, Hawaii and Iceland, result when underground rivers of molten rock empty out, leaving channels up to 30 meters across. Planetary geophysicist Dave Blair of Purdue University in West Lafayette, Indiana and colleagues estimate that lunar caves could exist that are up to 5 kilometers across!


(Thurston Lava Tube, Hawaii)

Mounting evidence from the SELENE, LRO, and GRAIL spacecraft suggests the presence of vacant lava tubes under the surface of the Moon. GRAIL evidence, in particular, suggests that some may be more than a kilometer in width. Such large sublunarean structures would be of great benefit to future human exploration of the Moon, providing shelter from the harsh environment at the surface—but could empty lava tubes of this size be stable under lunar conditions? And what is the largest size at which they could remain structurally sound?

We address these questions by creating elasto-plastic finite element models of lava tubes using the Abaqus modeling software and examining where there is local material failure in the tube's roof. We assess the strength of the rock body using the Geological Strength Index method with values appropriate to the Moon, assign it a basaltic density derived from a modern re-analysis of lunar samples, and assume a 3:1 width-to-height ratio for the lava tube. Our results show that the stability of a lava tube depends on its width, its roof thickness, and whether the rock comprising the structure begins in a lithostatic or Poisson stress state.

With a roof two meters thick, lava tubes a kilometer or more in width can remain stable, supporting inferences from GRAIL observations. The theoretical maximum size of a lunar lava tube depends on a variety of factors, but given sufficient burial depth (500 m) and an initial lithostatic stress state, our results show that lava tubes up to five kilometers wide may be able to remain structurally stable.

Fans of science fiction Grandmaster Robert A. Heinlein find themselves nodding sagely, since reading all about such structures in his 1957 novel Menace from Earth:

Most of the stuff written about Bats' Cave gives a wrong impression. It's the air storage tank for the city, just like all the colonies have - the place where the scavenger pumps, deep down, deliver the air until it's needed. We just happen to be lucky enough to have one big enough to fly in. But it never was built, or anything like that; it's just a big volcanic bubble, two miles across, and if it had broken through, way back when, it would have been a crater.

Never one to neglect the adventuresome spirit of American youth, Heinlein obligingly provided lunar colonists with Storer-Gulls Wings for recreational use of lunar lava tubes.

Via The structural stability of lunar lava tubes.

Scroll down for more stories in the same category. (Story submitted 12/15/2016)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 0 )

Related News Stories - (" Space Tech ")

Is There Life In Outer Space? Will We Recognize It?
'The antennae of the Life Detector atop the OP swept back and forth...' - Frank Herbert, 1958.

Space Traumapod For Surgery In Spacecraft
' It was a ... coffin, form-fitted to Nessus himself...' - Larry Niven, 1972.

A Space Ship On My Back
''Darn clever, these suits,' he murmured.' - Jack Williamson, 1933.

Elon Musk Tweets Versions Of Clarke's Operation Cleanup
'Fortunately, the old orbital forts were superbly equipped for this task.' - Arthur C. Clarke, 1978.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

Ontario Starts Guaranteed Minimum Income
'Earned by just being born.'

Is There Life In Outer Space? Will We Recognize It?
'The antennae of the Life Detector atop the OP swept back and forth...'

Space Traumapod For Surgery In Spacecraft
' It was a ... coffin, form-fitted to Nessus himself...'

Tesla Augmented Reality Hypercard
'The hypercard is an avatar of sorts.'

A Space Ship On My Back
''Darn clever, these suits,' he murmured.'

Biomind AI Doctor Mops Floor With Human Doctors
'My aim was just not to lose by too much.' - Human Physician participant.

Fuli Bad Dog Robot Is 'Auspicious Raccoon Dog' Bot
Bad dog, Fuli. Bad dog.

Las Vegas Humans Ready To Strike Over Robots
'A worker replaced by a nubot... had to be compensated.'

You'll Regrow That Limb, One Day
'... forcing the energy transfer which allowed him to regrow his lost fingers.'

Elon Musk Seeks To Create 1941 Heinlein Speedster
'The car surged and lifted, clearing its top by a negligible margin.'

Somnox Sleep Robot - Your Sleepytime Cuddlebot
Science fiction authors are serious about sleep, too.

Real-Life Macau or Ghost In The Shell
Art imitates life imitates art.

Has Climate Change Already Been Solved By Aliens?
'I had explained," said Nessus, "that our civilisation was dying in its own waste heat.'

First 3D Printed Human Corneas From Stem Cells
Just what we need! Lots of spare parts.

VirtualHome: Teaching Robots To Do Chores Around The House
'Just what did I want Flexible Frank to do? - any work a human being does around a house.'

Messaging Extraterrestrial Intelligence (METI) Workshop
SF writers have thought about this since the 19th century.

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.