My suggestion to follow flight up with 🌙space👩‍🚀 still fits, and it could carry over my previous music suggestions of The Moon by the Flobots, and anything from the Voyager golden records

But then there's also the "live at piha" version of Alien by Broods, and another song called Alien by Spose

And Alpha Centauri by Noisia

And Take Me To Your Leader by Timmie Rogers (which, unrelated, probably partly inspired No Particular Place To Go by Chuck Berry)

That's before even digging into Digit's music library which includes a song called Goodnight Moon by Go Radio and idk what else

This is actually how my reply looks after already narrowing it down as much as I could. The alien audience is just too important to under-prepare for. No choice but to leave it to you to narrow it down the rest of the way