Answer:
I occur twice in eternity. And I'm always within sight.
What has ten letters and starts with gas?
Barren location, infertile and dry; my name means "to leave", it's not heard to see why
I'm a god, a planet, and measurer of heat. Who am I?
Raise your right appendage high above your head. Turn your head to the right and you will smell this.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.