Answer:
I am essential to life on earth! I am split into thirds. Two thirds are the same. One of the thirds is 8. The other two are 1 each.
You turn me over after you have traveled far. What am I?
I ask no questions, but receive a lot of answers. What am I?
I only exist when you are here. Where you never were I can never be.
I am in the past, never in the future. I don't exist, but have existed. I saw what you saw, and this is what I will ever see. What am I?
I am your mother's brother's only brother in law. Who am I?