@himmelszelt/nachtgestirn

nachtgestirn: German, "night luminary". A celestial body that shines at night, above all the Moon. Poetic, 18th to 19th century: Bürger, Voss, Kleist.

The Moon, as it actually looks tonight.

by Daniel Limberger · Last updated 2 October 2026 · Unfamiliar term?Unfamiliar term Like this one: a dotted underline marks a term this site explains. Hover it, or tap it on a touch screen, and its definition opens right where you are reading. The small numbered citations work the same way, with the source they point to.

The Moon as a renderable body rather than a point in the sky. Where it is, how large it appears, how it is tilted and lit, and how much of Earth’s own light reaches its night side all come from sternzeit: its phase and sun direction, its libration and position angle, its earthshine, and whether Earth’s shadow is falling on it. What is left is the look: a textured disc, shaded by the sunlight on its surface, ashen in earthshine, and during a lunar eclipse darkened and reddened by the sunlight Earth’s atmosphere bends into its umbra. Its glow in turn lights the night sky of dunstkreis.

This chapter is a placeholder: the library does not exist yet.

Watch the Moon

A Moon to turn through its phases. Not written yet.

Phase, libration and earthshine

What makes the Moon look the way it does tonight. Not written yet.

Code examples

Not written yet.