On the third day, God created the Earth. The stars, planets and indeed the universe was made on the fourth day. Thus, the earth is the centerpiece of creation, it is, in some sense, the most important place in the Universe although our modern cosmology teaches us that it is an insignificant speck in the cosmos. Just as life radiated out from the Garden of Eden into the wider world and covenant life radiated out from Israel to the Nations, we can expect life to radiate out from our garden home to other planets.
The other planets might conceivably contain plant life. Although earthen plants were created on the third day, when God spread out the expanse of the heavens on day four, he might have included edible plants on the other planets as a preparation for our arrival there in the future. Animals were created on days five and six, not in tandem with or before the other planets, and I doubt that they were created or could be self-sustaining on off-earth worlds. We do have a picture of how to get animals to these future homes however, and it is in the person of Noah.
Just as Noah delivered the animals to a renewed earth by traveling through a watery expanse, future colonizers can carry animals of all kinds through space to a new world. While the technological challenges to this seem insurmountable in our time, the passage of time coupled with technological progress guided by the Holy Spirit may provide avenues to this possibility in the future. Theologian James Jordan often refers to the biologist Rupert Sheldrake and his theory of morphic fields related to humanity and the cosmos. As Jordan puts it:
Sheldrake argues that while there is no inheritance of acquired characteristics in the genetic sense, there is such an inheritance in a field” sense. Each animal, crystal, human society, etc. has a “type,” and that “type” changes in time in response to changed conditions and as a result of habitual reinforcement. Changes in “type” of affect entire populations of a given kind of creature, and usually happen in response to catastrophic changes in environment. Such patterns or habits of existence exist at various hierarchical levels, so that as regards human life, certain sub-groups within a nation may become loosely patterned toward certain occupations, while the nation itself may become loosely patterned toward certain orientations, and the human race as a whole is being patterned by God’s hand toward her fulfillment and destiny.
Jordan cites Sheldrakian morphic changes as a reason for humans breaking into different colors, sizes and so on after the Flood. He speculates that humans and animals would undergo further catastrophic changes once removed to other planets.
Postmillenial Christians should rejoice in these possibilities. God has provided for expansion, dominion and worship of Christ to take hold across the Universe. Learning how to tend the waste places of Earth should teach us how to colonize and bring life to other planets. The Church will in the future be confronted with how to bring the sacramental life and the Scripture to these places, it cannot be left to a secular sphere. A society capable of reaching the planets would potentially be the Second or Fifth Christendom, and so the configuration of the Church might be very different at that time.