Superman may be a work of pulp fiction, but astronomers have identified where in space the alien immigrant hero’s home planet, Krypton, could have existed. And this location suggests maybe Clark Kent isn’t as youthful as he looks… even in glasses.
It’s a story we are all familiar with, and can immediately identify as the origin of Superman: An infant is rocketed from a world on the brink of destruction, arriving on Earth, where our yellow sun gifts the child with extraordinary powers. Raised by humble and honest Earthlings, this child is taught to use his powers for good. Flying above us but living among us, a shining example of truth and justice.
The story has been told and retold by hundreds of creators across media from comic books, movies, TV shows, cartoons, radio shows… Heck, I even had wallpaper that depicted it (if you’ve still got a roll, you know where I am). This origin has even been co-opted and subtly adjusted for other characters with their own rich, vibrant, and creative universes (we’re looking at you, Goku). As such, the origin of Superman is perhaps the strongest example of entertainment in modern mythology.
The way Superman’s origin has seeped into the zeitgeist is akin to how legends like the ancient Mesopotamian epic poem, the Epic of Gilgamesh, have many versions throughout history and eventually influenced other myths.
This modern myth is about to be retold in James Gunn’s Superman (2025). And just as historians have attempted to connect the stories of legend to actual events that have occurred, cosmic archeologists have attempted to trace a star around which Superman’s home planet of Krypton could have orbited. They began by searching for clues about the fictional world in nine decades of comic books that reference it.
Finding Superman’s home star system
In 2012, astrophysicist Neil DeGrasse Tyson arrived at such a star, concluding that if Krypton was real, it could have orbited the red dwarf star LHS 2520 located around 41.9 light years from Earth.
“This is a major milestone in the Superman mythos that gives our Super Hero a place in the universe,” then DC Entertainment co-publisher, Dan DiDio, said in a 2012 statement from the comic book publisher.
DeGrasse Tyson’s findings even earned him an appearance in 2012’s ACTION COMICS #14 in which he helped Superman pinpoint the location of Krypton’s home star.
“Having Neil deGrasse Tyson in the book was one thing, but by applying real-world science to this story, he has forever changed Superman’s place in history,” DiDio added. “Now fans will be able to look up at the night’s sky and say – ‘that’s where Superman was born’.”
True. But fans may also wonder, given this: how old is Superman anyway?
What do we know about LHS 2520, Krypton’s star system?
So, what do we know about LHS 2520, the pseudo-parent star of Krypton?
Also known as GJ 3707, this star is an example of a red dwarf, the most common type of star in the Milky Way and possibly the universe.
LHS 2520 is smaller than the sun, about 30% the width of our star, or around 3.3 times the size of Jupiter. It is also much cooler than the sun, with an effective temperature of between 4,400 to 6,700 degrees Fahrenheit (2,400 to 3,700 degrees Celsius). That makes it among the coolest stars in the universe, discounting so-called failed stars, brown dwarfs.
Given that, Superman is lucky that all our yellow dwarf star does is charge his cells like solar batteries. With an effective temperature of around 10,000 degrees Fahrenheit (5,700 degrees Celsius), it could have roasted Kal-El alive.
The coolness of red dwarf stars like LHS 2520 means they are often posited as stars likely to host habitable zones. Also known as Goldilocks zones, these are regions around a star within which planets can hang onto surface liquid water without it boiling or freezing.
With Kyptonians having biology so similar to humans, presumably, liquid water was a key element in their evolution and survival.
However, the distance to Krypton could reveal a key difference between humanity and Kryptonians (apart from the whole superpowers thing): the way they age.
How far away is LHS 2520 from Earth?
While a distance of 41.9 light-years away makes LHS 2520 fairly local to the solar system, it would still take light from this system nearly 42 years to reach us.
That means the journey for infant Kal-El would presumably have taken longer than 42 years. We do know that faster-than-light travel is possible in the DC Universe, the third Flash and fastest man alive (come at me, Barry Allen fans), Wally West, breaks light speed on the regular.
However, while early DC Comics showed the Kryptonians had technology far more advanced than we do, they were also depicted as being in their infancy in terms of space travel, with no true spacecraft. Certainly not one that could smash light-speed and get an infant Kal-El to Earth before adulthood.
Further to that, there’s evidence scattered across the Earth of the DC Universe that Kal-El’s ship didn’t break light speed.
The key piece of evidence that Kal-El didn’t break light-speed, and Einstein’s laws of special relativity that say no object with mass can accelerate to light-speed, while traveling to Earth, is Superman’s primary weakness: Kryptonite.
Usually depicted as a glowing green rock, though there are other colors with some wacky effects (red Kryptonite has been known to do everything to Superman from causing him to grow a beard, command ants, with fetching ant head no less, turn into a Super-toddler, and turn into a monkey) Kryptonite is pieces of the exploded planet Krypton.
These presumably wouldn’t have been ejected at the speed of light when Krypton exploded. Most Superman adaptations suggest Kryptonite arrived on Earth around the same time as Kal-El. He is often seen encountering Kryptonite as a teenager in Smallville (specifically 1957’s Superboy #61).
Heck, in the TV show Smallville, Clark arrives in Kansas in 1989 in a capsule within a shower of Kryptonite meteors!
So how long did the journey take, and how old does that make Superman?
That depends on whether you mean how old is Superman chronologically, or how old is Superman physiologically? That’s because, depending on the levels of sci-fi Kryptonian technology on display here, these answers could be vastly different.
Let’s look at how long it would have taken Superman to reach Earth with the best available human technology and ignore pesky details like fuel, etc…
Currently, the gold standard of crew-carrying spacecraft designed by humans is the Orion spacecraft, which will carry astronauts to the moon as part of the Artemis space program.
Upon its return from the moon, it is estimated that Orion will travel at around 25,000 miles per hour, 30 times as fast as a speeding bullet. If that sounds fast, Wally West will tell you it’s a snail’s pace compared to the speed of light, which is 670,000,000 miles per hour.
That means returning from the moon, the Artemis astronauts will be traveling at around 0.0037% the speed of light. Assuming a constant top speed for Orion leaving Earth, it would take about 1.14 million years to reach Krypton.
Ouch! But let’s give the Kryptonians some credit here and make some generous assumptions.
Remember what we said about Kryptonite arriving with Kal-El? We can now use it in favor of a quicker journey from Krypton.
Ejecta from celestial explosions can travel at a range of speeds, but the fastest ejecta we see is from exploding stars or supernovas. This can reach speeds as great as 10% of the speed of light. That means assuming a constant speed and no loss of energy, if Krypton exploded with supernova-like intensity, its ejecta would reach Earth after around just 420 years.
Thus, if Kal-El was traveling ahead of this debris, the planet exploded after he left, he would be approaching about 421 when he met the Kents. That means he’s way older than Jonathan and Martha, his adoptive mother and father.
Superman is normally presented as being in his early to mid-thirties in DC Comics, with stories that show him as being older, like Kingdom Come (arguably the best Superman story ever), set in alternative universes or “Elseworlds.”
So if he took 420 years to get here, and he’s been on Earth for 33 years at least, that means he’s a pretty spry 453-year-old.
Of course, Kyptonians may have had tech that made this journey possible even without vastly advanced space travel. They definitely had access to weird time-distorting tech and suspended animation. Just look at the timeless interdimensional realm called the Phantom Zone, where Kryptonians shoved their criminals, for instance.
Thus, Superman may only be chronologically 453 years old while still being biologically in his 30s.
Of course, none of this really matters when we’re indulging in the escapism provided by Superman for an incredible 87 years. After all, isn’t doing the impossible in the face of insurmountable odds what Superman is all about?
Superman soars into cinemas across Earth on July 11. Unlike Kal-El, it can’t get here quickly enough!