Sorry, this was posted yesterday.
www.abovetopsecret.com...
A deep hole on the moon that could open into a vast underground tunnel has been found for the first time. The discovery strengthens evidence for subsurface, lava-carved channels that could shield future human colonists from space radiation and other hazards.
It is not clear exactly how the hole formed. A meteorite impact, moonquakes, or pressure created by gravitational tugs from the Earth could be to blame. Alternatively, part of the lava tube's ceiling could have been pulled off as lava in the tube drained away billions of years ago.