The Solarians are a sapient species of spherical beings native to the interior of Sol. They possess the means to create spaceships which allow them to travel to other nearby star systems such as Sirius and Procyon; and seem to maintain friendly contact with other star-dwelling species such as the Sirians. Despite their advanced technology, they remain unaware of the existence of planets and skeptical of the very idea that atomic matter could naturally exist in the solid state.