The rock era and the space age exist on parallel time lines. The Soviets launched Sputnik in October 1957, the same month Elvis Presley hit #1 with “Jailhouse Rock.” The first Beatles single, “Love Me Do,” was released 23 days after John F. Kennedy declared that America would go to the moon (and not because it was easy, but because it was hard). Apollo 11 landed the same summer as Woodstock. These specific events are (of course) coincidences. Yet the larger arc is not. Mankind’s assault upon the heavens was the most dramatic achievement of the 20th century’s second half, simultaneous with rock’s transformation of youth culture. It does not take a deconstructionist to see the influence of the former on the latter. The number of pop lyrics fixated on the concept of space is massive, and perhaps even predictable. It was the language of the era. But what’s more complicated is what that concept came to signify, particularly in terms of how the silence of space was somehow supposed to sound.

The principal figure in this conversation is also the most obvious: David Bowie. In a playlist of the greatest pop songs ever written about life beyond the stratosphere, 1969’s “Space Oddity” would be the opening cut, a musical experience so definitive that its unofficial sequel—the 1983 synth-pop “Major Tom (Coming Home)” by German one-hit wonder Peter Schilling—would probably be track number two. The lyrical content of “Space Oddity” is spoken more than sung, and the story is straightforward: an astronaut (Major Tom) rockets into space and something goes terribly wrong. It’s odd, in retrospect, that a song with such a pessimistic view of space travel would be released just 10 days before Neil Armstrong stepped on the lunar surface. That level of pessimism, however, would become the standard way for rock musicians to write about science. Outside of Sun Ra or Ace Frehley, it’s hard to find serious songs about space that aren’t framed as isolating or depressing.

Bowie wrote about outer space a lot throughout his career, often brilliantly and seemingly any time he couldn’t come up with a better idea. The character of Major Tom was revisited in 1980’s “Ashes to Ashes,” except Tom was now a drug addict. “Life on Mars?” certainly seems like a space song, but the lyrics are too surreal to denote anything literal. Bowie made an album in 1997 titled Earthling that used the cosmos as context for where we already were. The most notable entry in his entire catalogue is The Rise and Fall of Ziggy Stardust and the Spiders from Mars, a 1972 concept album about an alien who becomes a rock star. It would earn Bowie the unofficial position of poet laureate of outer space.

Still, there are three details about Bowie’s cosmological obsession that complicate the conventional wisdom. The first is that “Space Oddity” was not inspired by NASA, but by Stanley Kubrick’s 1968 movie 2001: A Space Odyssey. It’s fiction based on fiction. The second is that Bowie’s space fixation usually focused on aliens coming to our world (as opposed to us going to theirs). This is the case not only in his music, but also in his 1976 film The Man Who Fell to Earth. The third detail is that Bowie generally used space as a narrative device. He did not try to give his music a distinctly non-terrestrial feel (half the songs on Ziggy Stardust are about aliens, but the music is textbook glam). The only time he directly tried to interpret the imaginary sonics of space—cold, mechanical chords devoid of hooks—was on the original version of “Space Oddity.” Still, the singularity of that interpretation can’t be minimized. The influence of his attempt had real ramifications. It remains ground zero for the ungrounded.

Space is a vacuum: the only song capturing the verbatim resonance of space is John Cage’s perfectly silent “4'33".” Any artist purporting to embody the acoustics of the cosmos is projecting a myth. That myth, however, is collective and widely understood. Space has no sound, but certain sounds are “spacey.” Part of this is due to “Space Oddity”; another part comes from cinema, particularly the soundtrack to 2001 (the epic power of classical music by Richard Strauss and György Ligeti). Still another factor is the consistent application of specific instruments, like the ondes martenot (a keyboard that vaguely simulates a human voice, used most famously in the theme to the TV show Star Trek). The shared assumptions about what makes music extraterrestrial are now so accepted that we tend to ignore how strange it is that we all agree on something impossible.

The application of these clichés is most readily seen in the dawn of heavy metal. The 1970 Black Sabbath song “Planet Caravan” processed Ozzy Osbourne’s vocals through a Hammond organ to create a sprawling sense of ethereal distance. Deep Purple’s 1972 “Space Truckin’” used ring modulation to simulate a colossal spacecraft traveling at high speed. The lyrical content of Led Zeppelin’s “No Quarter” is built on Norse mythology, but the dreamlike drone of John Paul Jones’s mellotron and Jimmy Page’s ultra-compressed guitar mirrored the sensation of exploring an alien landscape. Unsurprisingly, the ambiance of these tracks merged with psychedelic tendencies. The idea of “music about space” became shorthand for “music about drugs,” and sometimes for “music to play when you are taking drugs and thinking about space.” And this, at a base level, is the most accurate definition of the genre we now called space rock.

More ideologically intertwined with ’60s prog than ’70s metal, the qualities of space rock are delineated by the mood they manufacture: hypnotic song structures, punctuated by distortion that’s heavier than the riffs. The lyrics tend to be low in the mix and not particularly essential, but the focus on the galactic is overt: Hawkwind’s 1973 live album Space Ritual featured voice narration from sci-fi poet Robert Calvert. Because space rock songs tended to be long, meandering, and performatively trippy, they weren’t much played on commercial radio, with one notable exception: Pink Floyd. That exception, much like Bowie’s “Space Oddity,” culturally dwarfs the totality of its competition.

Dark Side of the Moon, Pink Floyd’s eighth studio album, is the most durably popular rock album ever recorded, selling nearly 50 million copies and remaining in the Billboard Top 200 for 917 weeks after its release in 1973. It’s a concept album, and it’s not about the moon. It does, however, allow a teenager lying in a dark room to feel as though that is where he’s going. The apotheosis of all the fake audio signifiers for interstellar displacement, Dark Side of the Moon (and its 1975 follow-up Wish You Were Here) perfected the synthesizer, defining it as the musical vehicle for soundtracking the future. Originally conceived as a way to replicate analog instruments, first-generation synthesizers saw their limitations become their paradoxical utility: though incapable of credibly simulating a real guitar, they could create an unreal guitar tone that was innovative and warmly inhuman. It didn’t have anything to do with actual astronomy, but it seemed to connote both the wonder and terror of an infinite universe. By now, describing pop music as “spacey” usually just means it sounds a little like Pink Floyd.

If America’s obsession with the space race during the 1960s explains the rise of space rock in the ’70s, it follows that waning public interest in NASA (post-Apollo) led to a decline in space-related music in the ’80s and ’90s. Tunes like “Space Age Love Song” by Flock of Seagulls or “Space Is the Place” by Spacehog did not seem inspired by anything unworldly; they just seemed to use the word “space” as a meaningless monosyllabic placeholder. Soundgarden’s “Black Hole Sun” derived not from an interest in the sky but from a misheard TV report. Even the most serious attempts contained elements of kitsch and caricature: the UK outfit Spacemen 3 was maybe the best of the bunch, but the group’s music was overshadowed by their comedic self-awareness. The last major rock album that felt like music from space was arguably Radiohead’s OK Computer, but the connection was ancillary. The band was simply using the instruments, tunings, and tempos that have become associated with space-age pop. The audience felt the correlation more than the artist.

What has happened, it seems, is that our primitive question about the moon’s philosophical proximity to Earth has been incrementally resolved. What once seemed distant has microscoped to nothingness. When rock music was new, space was new—and it seemed so far beyond us. Anything was possible. It was a creative dreamscape. But you know what? We eventually got there. We went to space so often that people got bored. The two Voyager craft had already drifted past Pluto before Nirvana released Nevermind in 1991. You can see a picture of a black hole in the New York Times. The notion that outer space is vast and unknowable has been replaced by the notion that space is exactly as it should be, remarkable as it is anodyne. In 1997, one of the former members of Spaceman 3, Jason Pierce, made an album with his new band, Spiritualized, titled Ladies and Gentlemen, We Are Floating in Space. That title was a reference to a Norwegian novel, but it accidentally illustrated precisely how much perception had changed. Space was no longer somewhere to go. Space was where we already were, all the time, and we were just floating along for the ride.

Chuck Klosterman is an author and essayist whose books include Fargo Rock City and But What If We’re Wrong?