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 ")

WINE Spacecraft To Extract Water From Asteroids
'Yes, strangely enough there was still sufficient water beneath the surface of Vesta.' - Raymond Z. Gallun, 1951.

Japanese Swordsmiths Take On Asteroids
'... a tiny, rocket-powered projectile, drove towards the mysterious bulk.' - E. C. Tubb, 1958.

Saturn's Rings To Vanish, Let's Mine Them While We Can
'...the valuable shards of what had once been satellites.' - Nelson S. Bond, 1941.

Negative Matter Fluid Theorized In New Paper
'Of course, being negative matter, when you push it, it comes toward you..' - Robert Forward, 1992.

 

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

Spicy Tomatoes Created With Genetic Engineering
How about mashed potatoes and brown gravy?

Driverless Hotel Rooms Predicted In 1828
'Did you never see a moving house before?'

Yandex Self-Driving Taxi Is Very Smooth
'The big car was slowing down, its computer brain sensing an exit ahead.'

Shrimp Actually Made Of Algae Is A New Wave Food
Bring in that crop algae.

Cosplay Style Wings Could Work On Moon
'They're lovely! - titanalloy struts as light and strong as bird-bones...'

Tesla Model 3 Has Outside Speaker Grille
Robert Heinlein does it again.

Arizona Luddites Attack Self-Driving Vehicles
'Trucks don't drive by themselves...' Or do they?

Organaut! Russians 3D Print Living Tissue In Space
'For a while your colonists will have to come up [to orbit] to the Hospital...'

WINE Spacecraft To Extract Water From Asteroids
'Yes, strangely enough there was still sufficient water beneath the surface of Vesta.'

Japanese Swordsmiths Take On Asteroids
'... a tiny, rocket-powered projectile, drove towards the mysterious bulk.'

Saturn's Rings To Vanish, Let's Mine Them While We Can
'...the valuable shards of what had once been satellites.'

Humans Could Take Up A LOT Less Space
We'd have a lot more room for gardening...

Implosion Fabrication Shrinks 3D Objects To Nanoscale
'Carter had watched miniaturization a hundred times...'

GMO Houseplant Cleans Your Air
Removes compounds too small to be captured by a HEPA filter.

Nova Meat Can 3D Print Your Dinner
Printing out chicken nuggets.

MIT Scientists Create 'Peek-a-Boo Prober' From Jetsons
Well, George, it's the latest thing.

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.