A barren and lifeless rock, Pesmenben I has no atmosphere to speak of. Several craters dot the planet where meteors have hit it on a regular basis. On the surface there is some volcanic activity caused by Pesmenben I's still volatile core. Due to the close proximity of the sun to this planet it is ravaged by flare storms twice during its orbit.
Several networks of caves have also been detected on the surface, giving rise to the rumor that a species of space slug might inhabit the planet. Thus far no proof of this has been found, especially because the immense heat would kill even those species that could survive the terrible cold of space.