Star Trek’s Non-Corporeal Aliens Explained

Welcome to Trekspertise, a series where we break down the technology, history, details, and decisions that make the Star Trek universe so complex — and so fun.

One of the primary features of “Star Trek” is theoretical biology. Given the wide panoply of alien species on display throughout the franchise, audiences have been invited to ponder alternate evolutionary paths besides the one that happened to bring us into being on Earth. What kind of planetary conditions would be required to form, say, a hyper-intelligent crystalline being? How did a horta evolve? What will we evolve into in the future? Will our brains adapt to become psychic over time? According to the “Star Trek: Voyager” episode “Threshold” (one of the show’s most outraging to fans), it was revealed that humans will eventually evolve into giant salamanders. 

This leads to a few logical evolutionary extremes, like the fact that some species on “Star Trek” have evolved into beings of pure energy. “Star Trek” has many examples of non-corporeal aliens who can only be perceived as light, as a psychic presence, as a sound, or as a vision beamed directly into our inferior, corporeal brains. To cite a notable example: In the original series episode “Is There In Truth No Beauty?,” audiences were introduced to the Medusans, a highly intelligent, telepathic, and empathic species whose light-constructed bodies are so wildly complex that any human looking at them would instantly go mad. Only a mentally disciplined species like the Vulcans could look at a Medusan, and even then required a special filtered visor (pictured above). 

These kinds of aliens expand the audience’s mind as to what can be considered life.

In looking at fictional non-corporeal species, “Star Trek” expands our horizons. We’re invited to ponder new perspectives about basic concepts like evolution, time, the nature of consciousness, and, perhaps, our own relationship to the cosmos. Non-corporeal entities are one of the coolest ideas “Star Trek” has to offer, and their recurring nature is a constant reminder that life is more complex, and the cosmos more ineffable, than we could ever hope to imagine. 

On “Star Trek,” non-corporeal aliens tend to appear as lights or clouds or glowing mists of energy. One might recall the smoke-like alien that made Kirk nervous in the episode “Obsession,” one of the more underrated episodes of the show. Others might immediately think of Zefram Cochrane’s glowing, cloud-like “companion” in the episode “Metamorphosis.” That entity had the ability to sort of intuitively communicate with Cochrane (Glenn Corbett), and could also heal diseases and sustain human life beyond its usual biological barriers. A common theme of non-corporeal entities on “Star Trek” is that they are godlike and powerful, able to tap into the powers of the universe in ways we don’t understand.

The Medusans may be one of the most popular non-corporeal entities on “Star Trek,” but fans of “Deep Space Nine” would surely want me to acknowledge the wormhole aliens, a.k.a. The Prophets. In that show’s pilot episode, “Emissary,” Benjamin Sisko (Avery Brooks) travels into a stable wormhole and encounters bodiless creatures who can only communicate with him by appearing as people from his memories.

The wormhole aliens from “Deep Space Nine” are so, well, alien, they don’t understand concepts like linguistic communication or linear time. They don’t see cause leading to effect, but rather a widespread series of events that happen all at once. Sisko has to do the impossible, and explain the human habit of seeing time as a straight line. 

And, of course, there are many species of godlike beings on “Star Trek” who often take the form of humans, despite not having physical bodies. Q (John de Lancie) from “Star Trek: The Next Generation” is one of these beings, as is Trelane (William Campbell) from the original series. Those two beings tend to see corporeal humans as lesser species and amuse themselves by taunting and playing with them. Less whimsical is Kevin Uxbridge (John Anderson), a member of a powerful energy species called the Douwd. Kevin took the form of a human, married, and witnessed his wife killed, leading him to, in a moment of ill-temper, commit instant galaxy-wide genocide of a single species. He’s the deadliest character in all of “Star Trek.” 

The list goes on. Q tormented the Calamarain, which exist as ionized gas. There are the Organians, the Lights of Zetar, and the godlike Metrons, the latter of whom oversaw the fight between Kirk (William Shatner) and the Gorn in the episode “Arena,” and plenty of other examples. In most cases, non-corporeal entities are so far beyond human experience, it’s difficult to communicate with them, much less come to some kind of diplomatic understanding. 

But sometimes non-corporeal entities do become our friends. On “Star Trek: Prodigy,” the character of Zero (Angus Imrie) is a Medusan who managed to construct a robot-like vehicle for themselves, allowing them to interact with us flesh-beings without exposing themselves. Sometimes the ineffability of the cosmos works in our favor.