 Gamow is well north of the equator, while Dalton and "the Twinned Ones" are well to the south.The orbits of the moon and stars are sufficiently inclined that the inhabitants of the planet have seldom seen an eclipse or occultation.McLaughlin pays homage to Asimov by naming the protagonist "Isak" and naming a historical figure Duke "Lagash", the name of the planet in "Nightfall".