Superman—an iconic hero of comic books, cartoons, films, and TV shows—originates from the planet Krypton. His story begins with baby Kal-El being sent in a rescue capsule from his dying planet to find a new home on Earth. Astronomers have speculated on where in the cosmos Superman’s home world might be located and tried to estimate how long his journey to Earth would have taken.

Where Is Krypton Located?

In 2012, astrophysicist Neil deGrasse Tyson, in collaboration with DC Comics, identified Krypton as potentially orbiting the star LHS 2520 (also known as GJ 3707), a red dwarf located 41.9 light-years from Earth. This star, found in the constellation Ophiuchus, is smaller than our Sun (about 30% of its diameter, or 3.3 Jupiter diameters) and cooler, with surface temperatures between 2,400°C and 3,700°C (compared to 5,700°C for the Sun).
Red dwarfs like LHS 2520 are often considered viable hosts for habitable zones where liquid water—and by extension, life similar to Earth's or Krypton's—might exist.

“This is an important milestone in Superman mythology, giving our hero a place in the universe,” said Dan DiDio, then co-publisher of DC Entertainment, in 2012. Tyson even appeared in Action Comics #14, helping Superman locate Krypton’s star.

But if Krypton is really that far away, how long did baby Kal-El’s journey take, and how old is he really?

How Long Would It Take to Travel at the Speed of Light?

A distance of 41.9 light-years means light from LHS 2520 takes 41.9 years to reach Earth. Since nothing with mass can travel at light speed (671 million km/h) according to Einstein’s theory of relativity, Kal-El’s journey must have taken longer. In DC comics, Kryptonians possessed advanced technology, but early stories suggest their spacecraft could not exceed light speed. This is supported by the presence of kryptonite—fragments of Krypton that arrived on Earth around the same time as Kal-El.

Kryptonite, as planetary debris, could not have been ejected at light speed. Maximum speeds for space debris—such as from supernova ejecta—can reach about 10% the speed of light (roughly 67 million km/h). If we assume Kal-El’s capsule traveled at a similar speed, the journey would have taken approximately 420 years. Add a year if Krypton exploded shortly after the launch. So chronologically, Superman would be around 421 years old when he landed in Kansas.

Comparison with Earth’s Technology

For context: modern spacecraft like Orion, used in NASA’s Artemis program, reach speeds of around 40,000 km/h (0.0037% the speed of light) when returning from the Moon. At that speed, it would take about 1.14 million years to travel 41.9 light-years.
Even assuming Kryptonian tech reached 10% of light speed, we’re still talking centuries of flight—highlighting just how advanced their civilization had to be to get Kal-El to Earth in one lifetime.

Physiological vs. Chronological Age

In most stories, Superman appears to be in his early to mid-30s, though in alternate universes (like Kingdom Come), he’s older. If we accept 420 years in flight and 33 years of life on Earth, his chronological age would be around 453 years.
However, his physiological age could be far younger, thanks to Kryptonian tech.

Kryptonians likely used time-slowing or stasis technologies. For instance, comics mention the Phantom Zone—an interdimensional pocket where time barely flows, used to imprison criminals. If Kal-El’s capsule had similar tech, he could have remained an infant throughout the journey.
This would explain how he arrived on Earth as a baby and grew up in Kansas like a regular child—albeit one who gains superpowers under a yellow sun.

Cultural Significance and Conclusions

Superman’s origin is a modern myth, comparable to ancient epics like the Epic of Gilgamesh. His journey from Krypton, inspired by real astronomical data, adds scientific depth to this myth. The 41.9 light-year distance and the estimated travel speed imply Superman is not just a hero but a kind of cosmic long-liver, potentially centuries old despite his youthful appearance.

The upcoming James Gunn film Superman (set for release on July 11, 2025) promises to retell Kal-El’s story—possibly with new details about his interstellar voyage. Whether it took 420 years or less thanks to Kryptonian technology, Superman remains a symbol of overcoming the impossible—from interstellar travel to fighting for justice on Earth.

So…

Superman’s journey from Krypton to Earth likely took about 420 years at 10% of light speed, making him over 450 years old chronologically. However, Kryptonian stasis technologies allowed him to remain a baby during the flight. This blend of science fiction and mythology makes Superman’s story unique, and the real-world connection to LHS 2520 adds a layer of cosmic credibility.