I came across this interesting article: “An Eastern Orthodox Perspective on Microbial Life on Mars” (Theology and Science 6:4, 2008). I’m not Eastern Orthodox, but I think this paragraph in the article’s conclusion is well written and well reasoned:

To be sure, there is nothing in Orthodox theological tradition that would affirm the possibility of life on other planets. In fact, to the Biblical writers, to the Church Fathers, and to the framers of the Orthodox liturgical texts, this would be a nonquestion. The geocentric attitude of the tradition essentially has no interest in life elsewhere, due to the actual portrayal of Creation in the Biblical texts and due also to the lack of knowledge in earlier ages about the extent, structure, and shape of the universe. This ‘‘structure’’ does not have a place for extraterrestrial life, mainly because it does not imagine, nor can it possibly conceive of, the possibility of such life. It must, however, be remembered that this is the result of ignorance about the wider universe, not a voluntary decision to reject such a possibility. At the same time—and very importantly—that same Biblical portrait of the universe, when combined with modern scientific knowledge, need not preclude the possibility of extraterrestrial life. Although all other knowledge beside the reality of God is of lesser importance for the Orthodox theological synthesis, scientific knowledge continues to reveal—even on a very rudimentary level—the secrets of a universe theologically apprehended as the work of the divine Creator. Eastern Orthodox theology can comfortably embrace that knowledge as a guiding light on its journey towards the Divine Source of all being. . . . This establishes, within an Eastern Orthodox mind-set, a much more flexible attitude, one that would be readily able to accept all extraterrestrial life-forms.