If the Grand Canyon contained no life, would it be ethical to strip mine it? Should we preserve the Mars for future generations (in terms of science, natural beauty, ethics or economics/resources)? In doing that are we harming people that could be helped today by those resources?
If you find a beautiful rock in the woods is it wrong/amoral to smash it? What about fossils? Is it ethical to burn art for heat?
These are important questions to ask and the answers are non-trivial.
"If the Grand Canyon contained no life, would it be ethical to strip mine it?"
You are implicitly invoking emotional reactions. Make them explicit. Spell them out.
You might find they can't survive such a process. This is a sign.
"Should we preserve the Mars for future generations (in terms of science, natural beauty, ethics or economics/resources)?"
If we are unwilling to land on it and exploit its resources sufficiently to live on it, what future generations? Nobody's there now!
Besides, unless you're living in the Olduvai Gorge right now, congratulations, you live in a place that has been "ruined" for future generations. How do you feel about that? If the answer is anything other than grateful, you need to carefully consider how your own (implicit) answers apply to your own world in the past. Future generations must exist before they can feel anything.
This is just emotion dressed up in spiritualistic trappings, not an argument.
If the Grand Canyon contained no life, would it be ethical to strip mine it? Should we preserve the Mars for future generations (in terms of science, natural beauty, ethics or economics/resources)? In doing that are we harming people that could be helped today by those resources?
If you find a beautiful rock in the woods is it wrong/amoral to smash it? What about fossils? Is it ethical to burn art for heat?
These are important questions to ask and the answers are non-trivial.