Not that long ago it was a doubtful idea that we would ever find planets outside our solar system. Yet today news comes that extra-solar planet number 700 has been located. Once in a while you will see this (or the possibility we may find life on one of those planets) offered by journalists as something that might, well... shake the faith of Jesus' followers right down to our boots. Because faith is such a precious, fragile little thing, you know.
There are a number of reasons people offer as to why life on other planets might disturb us, one of which is the notion that Jesus would have to visit each one and die horribly all over again. As one theologian recently put it, "It's been argued for a couple of centuries now whether one incarnation of God as Jesus Christ for the entirety of creation is sufficient."
Fortunately, the Scriptures have this covered.
According to the Apostles, the sacrifice of Jesus is of cosmic significance. It isn't limited to the planet it took place on; it isn't limited at all. In any way. It affects all of existence.
"Christ himself suffered on account of sins, once for all," St. Peter tells us, "the righteous one on behalf of the unrighteous. He did this in order to bring you into the presence of God," (First Letter of Peter chapter 3, verse 18, CEB). The Letter to the Hebrews says much the same thing: "We have been made holy by God’s will through the offering of Jesus Christ’s body once for all, (chapter 10, verse 10, CEB).
"Once for all" -- One death and resurrection, infinitely valuable, covers the sins of the universe, and what other universes there may be.
St. Paul put it so succinctly: "One died for the sake of all; therefore, all died," (Second Letter to the Corinthians chapter 5, verse 14, CEB).