In sci.space.policy Henry Spencer wrote:
In article ,
Chuck Stewart wrote:
You'd want to bury a Moon base -- either explicitly, or by moving
into a lava tube --

Hmmm... Which reminds me: anything resembling a lava tube ever found?

Yes. There are a number of "sinuous rilles", narrow deep meandering
valleys of roughly constant width, e.g. Hadley Rille where Apollo 15
landed, and they are almost certainly collapsed lava tubes. And some
rilles are intermittent: the valley stops abruptly and then picks up
again suddenly several kilometers later, and those almost certainly are
still-standing sections of tube. Similarly, there are places where a
rille suddenly continues as a line of craters/pits, presumably an area
of mostly-intact roof with some weak spots.

Moreover, the rilles are *big*: Hadley Rille is 1.5km across, although
some of that is undoubtedly the result of collapse of the rim after the
tube itself collapsed. (It's nowhere near that *deep*.)

An orbiter with penetrating radar is what we really need to definitively
confirm all this.

Or have a rover follow it - if possible - this will also give you actual
information as to how the inside looks like and how likely you are actually
to be able to use it to build a base in.

--
Sander

+++ Out of cheese error +++