Function moon_position 

pub fn moon_position(at: OffsetDateTime) -> Equatorial

Geocentric lunar position (equatorial, epoch of date).

Truncated ELP-2000/82 (Meeus ch. 47): ~10″ in longitude against the full theory; documented public claim ≤2′ vs AstroPy (which uses a fuller theory; treating UTC as dynamical time contributes ≤ ~40″). For anything site-relative use moon_position_topocentric — lunar parallax reaches ~61′.

use skymath::moon_position;
use time::OffsetDateTime;

let geocentric = moon_position(OffsetDateTime::now_utc());
assert!(geocentric.dec().degrees().abs() <= 90.0);