When it comes to superpowers, few heroes in American pulp lore come as stacked as Superman. The Last Son of Krypton has an impressive set of offensive powers such as heat-vision and ice-breath, but he also has an equally impressive set of passive powers such as his super senses. In fact, it is his incredible ability to see and hear at great distances (combined with flight and super-speed) that makes the Man of Steel such a reliable hero. But how powerful are these abilities, and do they have limitations? The short answer is… it depends on the era.
Arguably, Superman was most powerful during his Silver Age era, where he basically had the ability to blow out the sun like a birthday candle. His super senses defied scientific reason, even for comic books. In Superboy #167 baby Clark is causing trouble halfway across the globe, so Martha Kent lures him home by making pancakes, knowing her son will smell them even on the other side of the planet. But after DC revamped their characters post-Crisis On Infinite Earths, writer John Byrne significantly de-powered the Man of Steel. He could still see and hear at great distances, but his abilities were more grounded. He could hear a cry for help from across town, but not from across the solar system. His eyes were like binoculars, but not the Hubble Telescope.
Over the next couple decades, Superman’s abilities again grew in strength as each writer expanded his power levels slightly, until he was pretty much operating at demi-god level again. Not only could Superman see on a microscopic level (down to atoms), but he could also see on a telescopic level—meaning he could expand his vision to see the farthest reaches of the galaxy. On top of that, Superman could also see in infrared, thermal, and of course X-ray. He could even occasionally perceive ecto energy, the life-force given off by all living beings. But once again, DC found that their title character had become too strong for his own good, and again had him de-powered following another Crisis event, Flashpoint.
Like his 80s counterpart, New 52 Superman’s abilities were more grounded and less godlike. His super hearing was again limited, and was frequently exploited by opponents with sound-based powers and weaponry. His super vision allowed him to see within city limits, but not the far reaches of the galaxy. New 52 Supes was also younger and more inexperienced, meaning his abilities likely would have grown stronger over time, but ultimately this iteration of the Man of Steel would meet his end, eventually paving the way for DC’s Rebirth Superman. How powerful are the current Man of Tomorrow’s super senses? While he’s certainly not back to his Silver Age power level, writers have come up with clever ways for Superman to utilize his senses without entirely breaking the concept of physics.
While Superman in modern comics can scan a person’s heartbeat like a lie detector, he has to really focus in order to do it and the range is limited to a one mile radius. In a Batman/Superman story titled “Game Over,” Clark also uses this ability on a macroscopic level, listening to the collective “world pulse” of ambient heartbeats across the Eastern seaboard. When the background hum of human heartbeats goes up in a specific area, it’s usually a clear signal that a disaster is imminent. However, there are ways to work around Superman’s super hearing, such as the tactics employed by the Invisible Mafia—who used codenames that could be readily found on a grocery list and intentionally avoided using certain “red flag” words.
Though Superman can sense acoustics far beyond any normal human, it is a power he has learned to tune out whenever he’s not using it (as depicted in the film Man of Steel). Since there would be no way for him to function in a constant state of hyper awareness, Clark has to actively listen to get the full effect of his super hearing. And it is possible to use Superman’s acute hearing against him. In Batman #42 by Tom King, Poison Ivy gains control of Superman’s mind and uses the Kryptonian to keep tabs on Batman and Catwoman. Realizing that Superman isn’t in the clearest state of mind, Batman tricks his brainwashed ally into closely listening to him whisper…then casually knocks the Man of Steel out with a whistle. While whistling wouldn’t normally hurt Superman, it can be a quite a doozy when his super hearing is fully attuned. And extremely loud sounds can even hurt Superman when his super hearing isn’t active, such as Black Canary’s sonic scream.
Superman’s super scent doesn’t come into play often, but the Man of Steel’s sense of smell is nonetheless heightened to the level of a bomb-sniffing dog—at one point allowing him to sense a rare element called infinitium at a movie premiere in Action Comics (Vol. 2) #22. While his super-smell was more of a Silver Age gimmick, when Superman does utilize it in the modern comics it is akin to watching a CSI bloodhound examine a crime scene. But while the Man of Steel’s sense of smell is impressive, his nose is nothing compared to that of his dog Krypto, who can track just about anything or anyone within city limits.
But out of all of Clark’s super senses, his most utilized is his super vision. Combined with his X-ray vision, Superman’s Krptonian eyes give him an intimate view of Metropolis. Though he can no longer see to the edge of the universe, the range of his eyesight is still quite far; and still defies the laws of physics. Though DC still uses the term “X-ray” to describe Superman’s ability to see through solid matter, it has been previously established that his eyes emit no actual radiation (just lots and lots of heat). Rather than bombard people with cancer-causing optic rays, Superman uses a mix of different extrasensory perceptions to interpret images through solid matter, though he still can’t see through denser metals such as lead.
How powerful are the Last Son of Krypton’s super senses? More powerful than our Earthly brains can comprehend. To be Superman is to be a living god, and part of his godhood entails a certain level of omniscience. He can see people in danger from miles away. He can hear the collective panic of an entire city. But he can’t save everyone 100 percent of the time, because even without his secret identity, Superman is ultimately mortal. His super senses are both a blessing and a curse—he can hear the prayers of millions, but cannot answer every one of them. It’s worth noting that Superman can entirely turn off his super hearing at any point, but chooses not to because deep down he loves feeling connected to the world.