Ian Stoner has recently argued that we ought not to colonize Mars because (1) doing so would flout our pro tanto obligation not to violate the principle of scientific conservation, and (2) there is no countervailing considerations that render our violation of the principle permissible. While I remain agnostic on (1), my primary goal in this article is to challenge (2): there are countervailing considerations that render our violation of the principle permissible. As such, Stoner has failed to establish that we ought not to colonize Mars. I close with some thoughts on what it would take to show that we do have an obligation to colonize Mars and related issues concerning the relationship between the way we discount our preferences over time and projects with long time horizons, like space colonization.
