Riddle 1

I rise long slow and full
over your soft curves
I've had horns that obscured
my glowing face;

now they're gone,
but they'll return.
Sweet fluids flow
along your crevices;

You come alive
under my gentle light--
some unseen part of you
craves me, raves and howls

to bring me down to you.

When I'm dark, I'm new;
When I'm old, I light you;
I'm inconstant, but true;
Who am I, who are you?

By Jason Paul Fox
(Scroll to the bottom of the page to see the answers)

(The Full Moon and The Earth)
The key is the horns...
a crescent moon is like horns. And the howls.
A reference to the moon's influence on tides, gravity, orbits.
Finally, the last stanza is an obvious riddle for the moon and earth.