Superman, explained · Krypton and its tech

Krypton culture.

Rao, the language and the lost world of Krypton.

Krypton is Superman's lost home world, which circled a red sun called Rao. Each era reinvents it, from the Silver Age's Science Council to John Byrne's cold society of birthing matrices. The S began as an S for Superman, became the House of El crest in the 1978 film and came to mean hope in Superman: Birthright (2003–04). Kryptonian has been invented three times.

Read in depth All krypton and its tech

Updated 6 November 2026 · 9 sources

Pale crystal spires rising from a rocky plateau under a huge red sun

In depth

The full story.

Krypton died so that Superman could live, but the planet itself has never stayed still. Every generation of writers rebuilds it, and the details tell you a lot about the Superman of that era.

Krypton through the eras

Era	What Krypton is like	Confidence
Golden Age (1938–)	Older and more advanced than Earth. His parents are first called Jor-L and Lora	Likely
Silver Age	Ruled by the Science Council, which dismisses Jor-El’s warnings. The capital Kandor is stolen by Brainiac; Argo City survives, which is how Supergirl lives	Likely
Post-Crisis (Byrne, 1986–)	A cold, sterile society. After ancient “Clone Wars”, people rarely meet in person and babies grow in birthing matrices. Kal-El’s matrix opens on Earth, so in this version he’s technically born here	Likely
Birthright (2003–04)	Krypton lies in the Andromeda galaxy, and the S means hope	Likely
New 52 (2011–)	A scientific utopia whose people are brilliant from infancy	Likely
Man of Steel (2013)	Births are planned genetically, through the Codex, for set roles	Likely
Krypton (TV, 2018–19)	Houses El, Zod and Vex; Religious and Lawmaker guilds; Sagitari soldiers and “Rankless” citizens	Likely
Superman (2025)	Jor-El’s restored message shocks Kal-El: it urges him to rule	Confirmed

For Superman’s Kryptonian relatives, see the family tree and Kara Zor-El.

Rao: Krypton’s sun and god

Rao is a red sun. Under its light Kryptonians have no special powers, a rule set in Superman #141 (1960). That’s why Superman loses his powers under red sunlight: read red sun. In the New 52, astrophysicist Neil deGrasse Tyson helped DC place Krypton near a real red dwarf, LHS 2520, in the constellation Corvus, 27.1 light-years from Earth.

Rao is also Krypton’s god. Rao is first mentioned in a “World of Krypton” story in Superman #248 (1972). From the 1970s, under editor Julius Schwartz, Superman sometimes exclaims “Great Rao!” instead of “Great Krypton!” (Likely); one source dates the first use of the exact phrase to Action Comics #489 (1978), but we haven’t confirmed that. In Super Friends #47 (August 1981), Superman says Rao is the Kryptonian name for God. On TV, Krypton has a religious leader called the Voice of Rao, and Smallville has a Book of Rao.

What does the S mean?

The symbol on Superman’s chest has meant different things over the years. For how the costume itself changed, see what the S means.

Where	What the S means	Confidence
1938 onwards	Simply an S for Superman	Confirmed
Superman: The Movie (1978)	The family crest of the House of El, which was Marlon Brando’s idea	Confirmed
John Byrne’s The Man of Steel (comics)	Designed by Jonathan Kent, based on a Native American snake symbol for a healer	Likely
Superman: Birthright (2003–04)	The Kryptonian symbol for hope. Geoff Johns later said it is both crest and hope	Confirmed
Man of Steel (2013)	The House of El crest, which means hope on Krypton	Confirmed
Supergirl (TV)	The family motto “Stronger together”	Likely
52 and Action Comics	Turned upside down, it stands for resurrection	Likely

In short: it’s his family’s crest, and it means hope. We describe the symbol in words only, as it’s DC’s trademark. The full design history is in Superman’s costume history.

The Kryptonian language

Kryptonian has been invented three times:

Bridwell’s Kryptonese (1970s–1986). DC editor E. Nelson Bridwell built a 118-character alphabet, with notes on grammar and vocabulary, partly from the alien-looking squiggles letterers had drawn for decades. It was used until the 1986 reboot and was never published in full.
The DC Direct alphabet (about 2000). A simple 26-letter cipher in which each symbol stands for an English letter.
Schreyer’s Kryptonian (2013). For Man of Steel, linguistic anthropologist Christine Schreyer of UBC Okanagan created about 300 words, with subject-object-verb word order. Kirsten Franson designed the glyphs. You see it written on screen far more than you hear it spoken.

Houses and the Science Council

The House of El sits at the heart of every version: Jor-El, Lara and Kal-El, plus Zor-El, Alura and Kara. The Science Council rules Krypton in Silver Age stories and in Man of Steel. The comics have no fixed system of guilds; those come mostly from the Krypton TV series. Krypton’s humane answer to crime, the Phantom Zone, was Jor-El’s discovery.

Era by era.

The same Superman, rewritten for every generation.

Golden Age (1938–1956)

Krypton explodes briefly in Action Comics #1 and is named in Superman #1 (1939): an older, more advanced world than Earth.

Silver Age (1956–1986)

Ruled by a Science Council that ignores Jor-El. Kandor is stolen by Brainiac, Argo City survives, and the red sun Rao is established (Superman #141, 1960).

Post-Crisis (1986–2011)

John Byrne's Krypton is cold and sterile: people rarely meet, and babies grow in birthing matrices.

New 52 (2011–)

A scientific utopia. Neil deGrasse Tyson placed it near the real red dwarf LHS 2520, 27.1 light-years away in Corvus.

Film and TV

Man of Steel (2013) has genetically planned births; Krypton (TV, 2018–19) adds Houses, guilds and the Voice of Rao.

Questions.

What is Rao?

Rao is the red sun that Krypton orbited. Under a red sun, Kryptonians have no powers, which is why Superman is only super on Earth, under our yellow sun. Rao is also Krypton's god, and some TV versions, such as Krypton and Smallville, show a religion built around him.

Is Kryptonian a real language?

It has been invented three times. DC editor E. Nelson Bridwell built a 118-character alphabet in the 1970s, DC Direct made a 26-letter cipher around 2000, and linguist Christine Schreyer created about 300 words for Man of Steel (2013).