I am don't believe if there any posible savior other then Jesus. Vatican not sure.
Acts 4:9 if we are examined today concerning a good deed done to a crippled man, by what means this man has been healed, 10 be it known to you all, and to all the people of Israel, that in the name of Jesus Christ of Nazareth, whom you crucified, whom God raised from the dead, in him does this man stand here before you whole. 11 He is 'the stone which was regarded as worthless by you, the builders, which has become the head of the corner.' 12 There is salvation in none other, for neither is there any other name under heaven, that is given among humans, by which we must be saved!"
of course there are many such scriptures in the Bible.
but notice that the Bible does qualify it just slightly, it says "given among humans".
my brother-in-law says that the day that they discover intelligent life on other planets is the day he becomes an atheist.
that sounds like a pretty dangerous gamble to me!
since the Bible isn't clear about whether there is life on other planets or not, it also isn't clear about how they fit into the plan of salvation, or even if they do.
it's purely speculation at this point.
since it is speculation, I wouldn't say a person can't be a Christian if they think there could be intelligent life on other planets.