I'd agree with koraks, first try printing overall at a harder grade to improve the contrast (assuming you're using VC paper). Then generously burn in the sky, blending from black at top to lighter gray at bottom.
Dodge the areas of the ground during the base exposure where you want to retain detail, maybe using a dodging mask cut to fit the shape of the ground and cliffs.
It looks like you have enough detail in the ground to get what you want out of it.
This is a tough one, given that there was no moon out and I assume no other sources of illumination for the ground. I would guess the density of the ground in the negative is not much more that the sky itself?
I know fiber paper isn't cheap, so you don't always want to waste it trying different techniques. Often I'll work out my contrast settings and burning/dodging plan on RC paper, then translate that to fiber. The times and contrast levels won't match initially, but once you find your base exposure time and contrast level on fiber, the time ratios for burning/dodging should be pretty close to what you did on RC. Plus, I find RC has less of a dry-down effect and obviously dries quicker than FB, so you get to assess the results quicker.
If you have a chance to pick up Tim Rudman's book "The Photographer's Master Printing Course", there's a lot of great techniques in there. Good Luck!