There are only two possible reasons that it would be wrong to engage in an activity that causes pollution: because pollution harms ecosystems, which are valuable in themselves  or, ecosystems aside, because pollution harms human populations  Either way, it would not be wrong to perform mining operations on Mars
There are no ecosystems on Mars.
 Although doing so would pollute Mars, the small human presence needed to run the mining operation would be completely protected from the Martian environment and would suffer no harm