Check this URL:

Notice what looks like a 'crater' [the largest depression] at the bottom half
of the clearly-imaged comet nucleus [left image].

It is not a crater!

If you study the shadows of that big depression, you'll
see that it is MUCH DEEPER than any 'crater'.
It is a cavern!...It has to be!....Maybe even a partial tunnel....
Thus we have space history!....
For the FIRST time ever a spacecraft has imaged a verifiable
CAVERN (a rather large one, too) on another celestial body!

IMAGINE! If a few hundred billion-dollars were available,
a habitable, sunshielded structure could be built in that CAVERN
inside that comet nucleus....Yea, I know! That's a flight of fancy
and wishful-thinking...still....What a view you would have
from just outside the lip of that cavern [protected behind several panels of
bulletproof glass].

cheers.

Jacob

A Bit off topic. I've had to borrow another PC this morning
to post this [The server I use is down].

"This planet has a 100 percent mortality rate."