Lunar lava tube
Lunar lava tubes are sub-surface tunnels on the Moon that are believed to have formed during basaltic lava flows. When the surface of a lava tube cools, it forms a hardened lid that contains the ongoing lava flow beneath the surface in a conduit-shaped passage. Once the flow of lava diminishes, the tunnel may become drained, forming a hollow void. Lunar lava tubes are formed on surfaces that have a slope that ranges in angle from 0.4–6.5°. Lunar lava tubes may be as wide as 500 metres (1,600 ft) before they become unstable against gravitational collapse. However, stable tubes may still be disrupted by seismic events or meteoroid bombardment.
One such area containing lava tubes and rilles is the Marius Hills region. In 2008, an opening to such a lava tube in this area may have been discovered by the Japanese Kaguya spacecraft. The Hadley Rille may have been a partly roofed lava channel, some parts of which have since collapsed. There may also be lava tubes in the Mare Serenitatis.
Lunar lava tubes may potentially serve a role as enclosures for manned habitats. Tunnels larger than 300 metres (980 ft) in diameter may exist, lying under 40 metres (130 ft) or more of basalt with a stable temperature of −20 °C (−4 °F). These natural tunnels provide protection from cosmic ray radiation, meteorites, micrometeorites, and ejecta from impacts. They are shielded from the variations in temperature at the lunar surface, which would provide a stable environment for inhabitants. Lunar lava tubes are typically found along the boundaries between lunar mares and highland regions. This would give ready access to elevated regions for communications, basaltic plains for landing sites and regolith harvesting, as well as underground mineral resources.
- Greeley, Ronald (December 1971), "Lava Tubes and Channels in the Lunar Marius Hills", The Moon 3 (3): 289–314, Bibcode:1971Moon....3..289G, doi:10.1007/BF00561842
- Cruikshank, D. P.; Wood, C. A. (March 1972), "Lunar Rilles and Hawaiian Volcanic Features: Possible Analogues", The Moon 3 (4): 412–447, Bibcode:1972Moon....3..412C, doi:10.1007/BF00562463
- Handwerk, Brian (October 26, 2009), First Moon "Skylight" Found -- Could House Lunar Base?, National Geographic, retrieved 2011-01-27
- Greeley, Ronald (May 1971), "Lunar Hadley Rille: Considerations of Its Origin", Science 172 (3984): 722–725, Bibcode:1971Sci...172..722G, doi:10.1126/science.172.3984.722
- Coombs, Cassandra R.; Hawke, B. Ray (September 1992), "A search for intact lava tubes on the Moon: Possible lunar base habitats", In NASA. Johnson Space Center, The Second Conference on Lunar Bases and Space Activities of the 21st Century (SEE N93-17414 05-91) 1, pp. 219–229, Bibcode:1992lbsa.conf..219C
- Scientists eye moon colonies — in the holes on the lunar surface, Daily News, retrieved 13 October 2011
- Spelunking the Lunar Landscape, retrieved 13 October 2011
- Very Clever! LRO Views Huge Lava Tube Skylight in Mare Ingenii, Universe Today, retrieved 13 October 2011
- York, Cheryl Lynn et al. (December 1992), "Lunar lava tube sensing", Lunar and Planetary Institute, Joint Workshop on New Technologies for Lunar Resource Assessment, pp. 51–52, Bibcode:1992ntlr.work...51Y
- De Angelis, G. et al. (November 2001), "Lunar Lava Tubes Radiation Safety Analysis", Bulletin of the American Astronomical Society 33: 1037, Bibcode:2001DPS....33.1003D
- Walden, Bryce E. et al. (January 1998), "Utility of Lava Tubes on Other Worlds", Workshop on Using In Situ resources for Construction of Planetary Outposts, p. 16, Bibcode:1998uisr.work...16W
- O'Neill, Ian (October 27, 2009), "Living in Lunar Lava Tubes", Discover News, retrieved 2012-01-05