In keeping with the Christmas theme, "A Spaceman Came Travelling" is a re-telling of the Christmas story with a sci-fi twist. The song is from Chris de Burgh's second album, Spanish Train And Other Stories (1975). It's had good success, particularly in the UK and Ireland, where it's been released as a single multiple times, reaching the Top 40 in its 1986 release.

I've seen Chris de Burgh in concert twice, at Hamilton Place (theatre) in Hamilton and at Maple Leaf Gardens (arena) in Toronto. The Hamilton Place show was set up to be filmed for TV, and when I went looking for a video of this song on YouTube, I was surprised to find footage from that very April 1983 show. It appears below.

Video shows that de Burgh plays this song various different ways. It's in the key of D minor, and in the video below he plays it with his guitar capoed at the fifth fret, with the chords transposed to the key of A minor. In more recent video, he plays it without a capo on the guitar (and playing it in D minor, of course). Here's an example of that: https://www.youtube.com/watch?v=SowmY4C_naQ  I've transcribed it the second way, to be played without a capo. It's really the same key either way, just two different ways of playing it.

The chord chart:
https://www.angelfire.com/planet/zerofret/crd/deburghc-aspacemancametravelling.txt

Audio (studio version): https://www.youtube.com/watch?v=By9128_X_bQ