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Wakusei Planets惑星

The Sun, the planets and their moons as a clean line drawing, a shaded realistic drawing or a painted surface map, with real sizes, tilt and rotation, and the moons where they are at any date and time.

Wakusei is the Japanese word 惑星 for a planet. About the name

Contents

Reference · Facts, line drawings and positions

Apparenttype

What the sky shows of a body at a time: its pose, the latitude the viewer sees it from (how open its rings are), the longitude at the middle of the disc, the phase and the size.

Import it

import type { Apparent } from "@johnmorrisdotca/wakusei-planets";

Definition

interface Apparent extends Pose {
    id: BodyId;
    time: number;
    subObserverLat: number;
    centralMeridian: number;
    phaseAngle: number;
    illumination: number;
    distanceKm: number;
    diameterDeg: number;
    frame: {
        right: Vec3;
        up: Vec3;
        toward: Vec3;
    };
}

Members

NameTypeDescription
idBodyId

How the body is turned.

timenumber

The instant, in milliseconds since 1970.

subObserverLatnumber

Degrees above (positive) or below the body's equator that the viewer sees it from: how open its rings are.

centralMeridiannumber

The longitude at the middle of the disc, degrees east, 0 to 360.

phaseAnglenumber

The Sun–body–viewer angle in degrees: 0 is full, 180 is new.

illuminationnumber

The fraction of the disc that is lit, 0 to 1.

distanceKmnumber

The distance from the viewer in kilometres.

diameterDegnumber

The angular diameter in degrees.

frame{ right: Vec3; up: Vec3; toward: Vec3; }

The viewer's frame in J2000 ecliptic vectors, to turn more vectors into the same view.

poleVec3

The north pole.

meridianVec3

The direction of longitude 0 on the equator.

lightVec3

The direction of the Sun, from the body.

Examples

import { apparent, type Apparent } from "@johnmorrisdotca/wakusei-planets";

const moon: Apparent = apparent("moon", Date.UTC(2026, 10, 24, 14));
console.log(moon.illumination.toFixed(2));
1.00

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/wakusei-planets 0.24.0.