Actually, this is a bogus question, since no one asked it, but I thought it was such a good question that I would answer it anyway.
I observe that since God is God, He can do anything He likes. If He chooses to create life on Mars, that’s His business. If He wants to create sentient life throughout the universe to give Himself more glory, He doesn’t need our approval to do it. Of course we can speculate about this. If Jesus died on the cross to save us from sin, what about people on other planets? Are we supposed to evangelize them, or are we the only ones in need of salvation? Or does God have a plan of salvation for each species? How often and in how many ways did Jesus take upon flesh, and in which ways did He die to save souls? How can we reconcile this with the idea that Jesus died once for all? The mind boggles, as it ought when we contemplate God.
However, all this speculation is human vanity. Or perhaps even anticipatory jealousy. Does God love us less if He adopts other children? Instead of whining, we should be glorifying God. Instead of wondering if hypothetical creatures have splinters in their eyes, we should be busy taking the beams out of our own eyes.