The moral obligation to support space exploration follows from our obligations to protect the environment and to survive as a species. It can be justified through three related arguments: one supporting space exploration as necessary for acquiring resources, and two illustrating the need for space technology in order to combat extraterrestrial threats such as meteorite impacts. Three sorts of objections have been raised against this obligation. The first are objections alleging that supporting space exploration is impractical. The second is the (...) widely held notion that space exploration and environmentalism are at odds with one another. Finally, there are two objections to using space resources that Robert Sparrow has raised on the topic of terraforming. The obligation to support space exploration can be defended in at least three ways: (1) the "argument from resources," that space exploration is useful for amplifying our available resources; (2) the "argument from asteroids," that space exploration is necessary for protecting the environment and its inhabitants from extraterrestrial threats such as meteorite impacts; and (3) the "argument from solar burnout," that we are obligated to pursue interstellar colonization in order to ensure long-term human survival. (shrink)