About The Moon Tracker

The Moon Tracker shows the real Moon and Sun from any town or city on Earth, at any date and time, as if you were standing there and looking at the sky.

Who it is for

Many people follow the Moon. Muslims watch for the new crescent that starts each Hijri month. Chinese, Vietnamese and Korean families keep the lunar calendar for festivals. Hindus follow tithis and moonrise for fasts such as Karwa Chauth. Buddhists keep Uposatha days, Jewish communities mark Rosh Chodesh, and many others gather at the full moon. Photographers plan moonrise shots, and anglers watch the Moon behind the tides. The site has a page for each of these, in English and Arabic.

How it works

• Positions of the Sun and Moon come from Astronomy Engine, an open-source library by Don Cross that agrees with the US Naval Observatory’s NOVAS software to within one arcminute.
• Crescent visibility uses the published criteria of Odeh (2006) and Yallop (1997). The Umm al-Qura rule is checked at Mecca.
• Eclipse dates, types and times agree with NASA’s eclipse catalogue by Fred Espenak and Jean Meeus to within about a minute.
• Towns, elevations and time zones come from GeoNames (towns of over 15,000 people).
• Everything is calculated in your own browser. Nothing you choose is sent to us.

What it is not

The Moon Tracker gives calculations, not sightings, and it is not a religious authority. Weather, haze and the eyesight of observers are not included. For the start of a month or a fast, follow the authority your community trusts.

Credits

Astronomy Engine by Don Cross (MIT licence). Moon and Sun surface maps by Solar System Scope, based on NASA data (CC BY 4.0). Ground photo “Moonless Golf” by Greg Zaal, Poly Haven (CC0). Earth image: NASA Blue Marble. Cities, elevation and time zones: GeoNames.org (CC BY 4.0). Stars: Hipparcos and Yale Bright Star catalogues via d3-celestial (BSD licence). Country outlines: Natural Earth via world-atlas. Share icons: Simple Icons (CC0); the names and logos belong to their owners.

Get in touch

Found a mistake, a missing town or an idea for the site? Write to contact@themoontracker.com, or see the contact page.