During the afternoon of October 26, 1976, Trish Campo, former chief administrator of Brother Studios recalled Brian at the studio sitting at a hammond B3 organ, absently gazing at the giant circular stained glass window over him depicting planets and stars. Later that afternoon, Campo heard "Solar System" coming out of the studio. Brian explained that the lyrics were written while driving to a parents' meeting at his daughters' school. When he got home, he finished the song on his piano, exclaiming, "This is a gr-eat song! These lyrics are great. This melody is great. (whistles) I've got a beauty here!" He then named it one of his favorites on Love You, adding, "When I'm 90, I'm gonna be as proud of that song as I am now."
The song uses a triple meter, a trait reminiscent of the 1968 Friends album and contains flashes of choral brilliance.[according to whom?] The subject and lyrics are amateurish and the song is quirky and baffling, but it is ultimately endearing.[according to whom?]
Music critic Robert Christgau loved the Love You album and gave it an A overall; and he found Solar System to be "impossible to shake", and characterized by a "silliness that registered as charming".