lunar lava tube

sub-surface tunnel on the Moon, believed to have formed during basaltic lava flows. 

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Wikimedia, Wikidata
lava tube, subterranea, 
,

• Freebase entry^@
  

lava tube – 

Frameless

Lunar collapse pits

Mare Ingenii presumed lava tube skylight

Type	Date	Description	Keywords	Notes	Source
link		Freebase entry@			Wikidata
image	2014	Lunar collapse pits			Wikimedia
image	2010	Mare Ingenii presumed lava tube skylight			Wikimedia

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