This is the closing track of Down In The Weeds, Where The World Once Was. The album came in the aftermath of Conor Oberst's 2017 divorce from the Mexican musician Corina Figueroa Escamilla, whom he'd been married to for seven years. Here, Oberst intricately dissects the broken marriage as he reflects on the distrust, wanderlust and flying plates.
Their divorce is amicable, and Corina features on the record's opening track, "Pageturners Rag
Oberst wanted to encapsulate the highs and lows of life throughout the Down In The Weeds album. The second track, "Dance And Sing," opens with the line:
Keep on going like it ain't the end
"Comet Song" ends with the lyric:
You're approaching, even as you disappear
Oberst explained to Uncut magazine: "The line 'I got to keep on going like ain't the end,' I felt it was this statement. For the same reason I wanted the last lyrics to be 'You're approaching it as you disappear.' This might sound a little cheesy, but to me it's a circle of life situation. A lot of times I think I'm going a straight line of forward motion, only to realize you come back around. It's hard to know that sometimes if you don't have an aerial view of your path through. And you realize you're back where you started."
Comets go around the Sun in a highly elliptical orbit. Oberst explained to Apple Music he named this track "Comet Song" in relation to the circle of life because a "comet just goes in a circle."
This song, along with most of the other tracks on the album, features rhythmic contributions from Red Hot Chili Peppers bassist Flea and Queens of the Stone Age drummer Jon Theodore. Bright Eyes multi-instrumentalist Nate Walcott was the touring pianist and keyboard player for the Red Hot Chili Peppers during their The Getaway World Tour. Also, Flea previously played with Theodore on Mars Volta's 2003 album De-Loused in the Comatorium.