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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 · The realistic Earth's pure parts

subsolarPointfunction

The point where the Sun is at the zenith at ms: latitude is the Sun's declination, longitude runs west at 15 degrees an hour.

Import it

import { subsolarPoint } from "@johnmorrisdotca/chikyu-earth/realistic";

Definition

function subsolarPoint(ms: number): GeoPoint

Parameters

NameTypeDescription
msnumber

A moment, in milliseconds since the Unix epoch.

Returns

GeoPoint

The longitude and latitude on the Earth that has the Sun straight overhead.

Examples

import { subsolarPoint } from "@johnmorrisdotca/chikyu-earth/realistic";

const sun = subsolarPoint(Date.UTC(2026, 5, 21, 12));
console.log(sun.lat.toFixed(1), sun.lon.toFixed(1));
23.4 0.5

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/chikyu-earth 0.11.0.