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Chikyu Earth地球

A line-drawn globe of the world's countries that turns at the Earth's own rate, with an optional realistic Earth from space and markers for any place.

Chikyu is the Japanese word 地球 for the Earth. About the name

Contents

Reference · Printable sheets: the globe and a world map to colour, my country, day and night, the seasons

dayNightViewfunction

The turn of the globe on the day and night sheet for a moment: the Sun's longitude less 90 degrees at the middle, so the lit half is on the right, tipped to show the north.

Import it

import { dayNightView } from "@johnmorrisdotca/chikyu-earth/sheets";

Definition

function dayNightView(ms: number): { centre: [number, number]; sun: { lon: number; lat: number; }; roll: number; }

Parameters

NameTypeDescription
msnumber

The moment, in milliseconds since the Unix epoch.

Returns

{ centre: [number, number]; sun: { lon: number; lat: number; }; roll: number; }

The place at the middle of the globe, the place where the Sun is straight overhead and the roll of the globe about the line of sight, in degrees.

Examples

import { dayNightView } from "@johnmorrisdotca/chikyu-earth/sheets";

const view = dayNightView(Date.UTC(2026, 5, 21, 12));
console.log(view.sun.lat.toFixed(1));
23.4

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/chikyu-earth 0.51.1.