I was listening to this song for weeks, not paying much attention to the words, only now realized it's about aliens. The 51 made me think about the rest of the lyrics and the song makes sense. The 'saying hi' part is so cute in this context.
Easily one of their best, yeah. It's a shame it's not on their best of, otherwise the bandwagon fans would be scrobbling it a lot higher up..well, anyway, I've finally memorised the last part now! It's a good feeling.