Our Moon Phase Prints are the most accurate picture of the moon on a given date and location, achieving this level of accuracy is challenging for a variety of reasons explained in this condensed scientific article.

Your Moon Map/ Moon Phase Print is a unique bespoke piece of art thanks to the dynamic facts listed below.

The suns path is complex as it is determined from an observer on earth looking at an object (the moon) whose light source (the sun) are both moving at different speeds, orbits and distances. As such the moon phase print firstly has to be rendered in 3d and the shadows can then be accurately calculated and displayed. Pictures taken via observatories and space missions are used as supplementary assets as there picture quality was often not adequate.

The illumination of the moon is dynamically effected by its light source the sun, the earth also has an effect on the illumination of the moon this is called “earthshine” this however is due solely to the Suns light, bouncing from the earth back to the moon. This effect however minuscule (>1%) was measurable and calculated. 

The below are common phases and there respective names

This variable was another reason the majority of other online resources are inaccurate. The Moon orbits the earth in a non linear way for example at the largest orbital deviation (Moon at apogee) the distance is calculated at 252 088 miles away from Earth and at the smallest orbital distance (Moon at perigee) it is 225 623 miles.

This variation in distance not only effects the visual image of the moon but also the speed in which the moon is travelling (faster as its distance towards the earth reduces).

The moon and everything in space is in motion, the moon is in a perpetual cycle of falling (non relative speaking) to earth and being acted upon by centrifugal and centripetal forces. The Earths gravity creates a constant pulling force upon the Moon and the moon does the same to the Earth.

All this needs to be calculated precisely to ensure the moon phase print is accurately. Any measure of error compounds.

Geographical coordinates are a system used to specify locations on the Earth’s surface. Our systems use Google Maps API to accurately determine this vairable, the user can simple search via their postcode, city or even place name.

We use the same proces to determine the earth location for our star maps Geographical coordinates are based on the Earth’s reference ellipsoid, a model that approximates the Earth’s shape as an oblate spheroid (a sphere flattened at the poles).

The coordinates are illustrated on the Moon Phase Print using the following denominations:

Latitude – is the angular distance north or south of the Earth’s equator. It is measured in degrees and ranges from 0° at the equator to 90° at the North and South Poles. The equator itself is defined as 0° latitude. Positive latitudes are used for locations in the Northern Hemisphere, while negative latitudes are used for locations in the Southern Hemisphere.

Longitude – is the angular distance east or west of a reference meridian, typically the Prime Meridian, which passes through Greenwich, London, UK. It is also measured in degrees and ranges from 0° to 180° east or west. The Prime Meridian is defined as 0° longitude, with positive longitudes to the east and negative longitudes to the west.

The geographic location on earth is one major vector for the calculation of your Moon Phase Print.

For the moon phase print the orbit of the moon (the lunar cycle) is very important, ensuring the moon is pictured at the optimum (culmination) phase/ time meaning the moon is at its most visible.

As such allowing users to specify a time would not be allow our system to take the optimum pictures and calculation of the moon.

In some worst case scenarios allowing the user to specify an exact time could result in the moon not being visible at all. So we removed this feature. The user has full control over the date and location and we then calculate the optimum time.

The moon at is furthest distance (Apogee) and its shortest distance (Perigee) effect is visual size from earth. For example the moon will appear 12% large at its Perigee than its Apogee phase, we however turned this feature off, as we believe it is far better visually to display the moon at its largest ratio optimally to the print, however we would be happy to turn this feature on if requested. It is a simple change in calculation to display the moon at its correct percent change, based on its position in the lunar cycle. This would result in the moon image being slightly smaller to the degree in which it is in the lunar cycle.