JavaScript examples for Node.js

The source file astronomy.js works as a Node.js module. Download the file into your project directory. Then in your own source file, do this:

const Astronomy = require('astronomy.js');

There are no external dependencies! Astronomy Engine is completely self-contained, and it always will be.

(By the way, you can use the same file astronomy.js for astronomy calculations inside the browser.)

Moon Phase Calculator

This example shows how to determine the Moon's current phase, and how to predict when the next few quarter phases will occur.

Planet Positions

Calculates equatorial and horizontal coordinates of the Sun, Moon, and planets.

Rise/Set

Shows how to calculate sunrise, sunset, moonrise, and moonset times.

Seasons

Calculates the equinoxes and solstices for a given calendar year.

Finds when the Sun, Moon, and planets reach their highest position in the sky on a given date, as seen by an observer at a specified location on the Earth. Culmination is also the moment a body crosses the meridian, the imaginary semicircle in the sky that passes from due north on the horizon, through the zenith (straight up), and then toward due south on the horizon.

API Reference

Complete documentation for all the functions and types available in the JavaScript version of Astronomy Engine.