On Lunar Astronomy
[How the astronomy of the inhabitants of the moon differs between lunar regions and from the earth]
Atque haec de itinere in Levaniam dicta sunto. Sequitur, ut de ipsius provinciae forma dicam, exorsus more geographorum ab iis, quae coelitus illi eveniunt.
Such has been said of the journey to Levania. Next I will speak of the nature of the place itself, beginning as geographers do with the things that happen in the heavens.
Etsi siderum fixorum aspectus tota Levania habet nobiscum eosdem ^87, motus tamen planetarum et quantitates ab iis, quas nos hic videmus, observat diversissimas, adeo ut plane alia sit totius apud ipsos astronomiae ratio.
Although the fixed stars appear everywhere in Levania, the same as they do to us, nevertheless we see differences in the movements and the magnitudes of the planets to such degree that they have entirely their own system of astronomy.
Quemadmodum igitur geographi nostri orbem Terrae dividunt in quinque zonas propter phaenomena codestia, sic Levania ex duobus constat hemisphaeriis ^88, uno subvolvarum, altero privolvarum ^89, quorum illud perpetuo fruitur sua volva, quae est illis vice nostrae Lunae, hoc vero Volvae conspectu in aeternum privatur ^90. Et circulus hemisphaeria dividens instar nostri coluri solstitiorum per polos mundi transit appellaturque divisor ^91.
Therefore, as geographers divide our sphere of the earth into five zones according to their celestial phenomena so is Levania divided into two hemispheres: one of these is the Subvolvan, the other is the Privolvan. The Subvolvans are forever blessed by the light from Volva [our Earth] which for them takes the place of our Moon. But the Privolvans are eternally deprived any sight of the Earth. The circle dividing their hemispheres, named the divisor, resembles the meridian passing through the solstices and the poles of our world.
Quae igitur utrique sunt communia hemisphaerio, primo loco explicabo. Itaque Levania tota vicissitudines sentit diei et noctis ut nos ^92, sed carent illi hac nostra annua varietate toto anno ^93. Per totam enim Levaniam aequantur dies fere noctibus, nisi quod privolvis regulariter omnis dies est brevior sua nocte, subvolvis longior ^94. Quid autem per circuitum annorum 8 varietur, infra erit dicendum.
Such things that are common to both hemispheres I will explain first. All Levania experiences the same changes of day and night as we do, but without our annual variations throughout the year. For throughout Levania the days are almost equal to the nights except for the Privolvans each day is always shorter than its night, and for the Subvolvans longer. The changes through a cycle of 8 years will be described later.
The Somnium Project 