The Cepheids were a sapient race of semi-humanoid beings who evolved on an unnamed desert world and were briefly relocated to a planet in the Cepheus 18 star system by the Galactic Empire. They were one of just two intelligent alien species humans discovered, the other being the Memes.


The Cepheids are relatively short bipeds and notable for their retractable proboscis, which they use for drinking. Their skin is wrinkled and brick-red in coloration, although it swells and loses the wrinkles when they drink enough water, since the excess is stored under their skin. They have small black eyes and lipless mouths.

Members of this species communicate by telepathy, although the physical mechanisms that allow them to do so are unknown. Their preferred environment is dry and hot. Even temperatures of 120 Fahrenheit (circa 48 Celsius) are considered cold by them. They can go over a week without drinking. Like humans, they require sleep. Their diet is completely herbivorous.

Culture and Society[]

Cepheid science has developed in completely different ways compared to that of humans. Their medical, biological and psychological sciences have advanced considerably, while their physical sciences have remained stagnant. They can produce pills which heal broken bones in fifteen minutes, although, due to physiological differences, none of their medicines would have any beneficial effect in humans.

The Cepheids are naturally peaceful creatures. It has been remarked that they have no criminals and no misfits in their society.


The Cepheids were discovered in 975 GE. Their home system was under human jurisdiction, and the aliens were regarded as "non-human subjects of the Emperor". They were found to be struggling to survive on a moribund planet with very scarce resources, and were thus relocated to a different, far more comfortable world at Cepheus 18 (probably the star 18 Cephei). Furthermore, the Empire granted the Cepheids enough autonomy to govern their own internal affairs, under Imperial supervision.

In the first two years since their relocation, it was noticed that no Cepheid had been born anywhere on the planet, which drew the attention of human administrators. As it turned out, the Cepheids were very happy with their new world, but felt that they had lost their way of life. In their old world, they struggled under unfavorable conditions, hoping to one day reach out the stars; and felt that they were very close to doing so when the humans came and "rescued" them. In their new world they could get all the food and water that they needed, without having to struggle for it. This, paired with the knowledge that they had become subjects of another race (even though one that treated them with kindness); and that the stars they had sought turned out to be already conquered by this other race; ended up having negative effects on their social morale. Collectively, the telepathic aliens had lost their will to live and thus stopped breeding.

The situation changed when the Cepheids managed to steal a large number of Imperial ships and flee from the system (and indeed the galaxy) en masse, hoping to colonize a new world in the distant Magellanic Clouds.

The were encountered again in 11867 GE, really in the Greater Magellanic Cloud, and human colonists withdrew.


It is the only intelligent alien life Asimov put into his Foundation universe, appearing in just one short story.

  • "Blind Alley"