Astrocraft

The positions of these planets in the sky are calculated using their orbital parameters (fully configurable), while also taking into account earth's own orbit. These include:

• Semi-Major Axis
• Orbital period
• Eccentricity
• Inclination
• Precession

The brightness or size of a planet is calculated using:

• Diameter and Albedo
• Distance to Earth / Observing Planet
• Distance to the Sun
• Phase Angle (Different phase curve models are used for different planets)

Satellites of planets (including The Moon) or even the Sun use the same algorithm. When the angular diameter of a planet exceeds a certain size, the mod switches from star-like rendering to vanilla-moon-like rendering.

Using a spyglass allows you to see stars, planets, asteroids or moons that are too faint to see with the naked eye. If you zoom in enough, planets can be rendered with a texture, some showing phases like the moon (Venus and Mercury).

Below is a table of the planets (except Earth), with descriptions of their in-game appearances:

Over 100 asteroids have also been added, including Vesta and Ceres. These appear similar to dim stars.

Moons

Both Jupiter and Saturn have easily observable moons. In a spyglass, they look like stars revolving around the planet. You can see moons move around over a single night, as they often have short orbital periods. You can also see the moons of Mars, Uranus, and Neptune with some difficulty.

Big Planets Mode

This option scales up the planets and renders planets using textures like the MC moon, rather than realistic star-like rendering.

See space from other planets

Using the "Observing Location" option, you can easily switch the perspective from Earth to any other object, including planets, moons, asteroids or even the sun. This shows you how other planets / moons appear from planets other than Earth (like Earth from Mars, or Jupiter from Europa). It also simulates how lighting changes as you get further from the sun (try Pluto).

You can also switch to other nearby stars, for example "Proxima Centauri B". The sun will be visible as a yellow star near Cassiopeia.

Configuration + Custom Planets

Planets are fully configurable, you can edit existing planets or even add your own.

You can also add or remove moons to each planet, which are editable just like planets. Setting a planet's model to "Star", will turn it into a star, you can make the solar system a binary stars system this way.

Below shows a custom planet so big that it is visible during the day:

Positions in the Sky

Unlike in vanilla minecraft, where the sun and moon always pass overhead, they are instead tilted by the latitude set in the configuration (30°N by default). Additionally, the sun's path is also affected by its declination which changes throughout the year cycle (365 ingame days by default). Disable the 'Tilted Sky' setting in the config for vanilla behavior.

Throughout the year, the sun moves relative to the stars, travelling through the zodiac. This determines which stars can be seen at a given time.

Changing Day / Night Lengths

Times of sunrise / sunset are also affected by the sun's declination, with longer days and shorter nights during the summer, and the opposite during the winter. Setting latitude to 90° or -90° in the configuration will simulate the polar day / night experienced at the poles.

The Moon

The moon's position relative to the sun will depend on the moon's phase. At full moon, the moon stays opposite the sun, just like in vanilla minecraft. However, during a crescent phase, the moon will appear just to the left or right of the sun, and can be seen during the day. This mod also adds moonlight, which lights up the night around the full moon.

Eclipses

A lunar eclipse occurs when a full moon coincides with the moon crossing the ecliptic, the moon turns red and moonlight dims. During a new moon, the moon can partially or fully cover the sun, blocking out the sunlight and dimming the sky until it is just like night-time. Other astronomical objects, such as Mercury and Venus also eclipse the sun, which you can observe as a small black spot traversing the sun's disk.

Here you can toggle stars or planets off, reduce star coloring, add your own stars and planets, and much more.

Magnitude Limit

This is the main option affecting performance, it changes how many stars are shown. Increase to 6 for a more detailed night sky. Reduce if you have performance issues, or you want to simulate urban light pollution.

Year Length

Default "Year Length" is 365.25 minecraft days, this also affects the orbital period of every planet / moon. On singleplayer worlds, this may be too slow for you, so you can reduce it to something like 96 days.

Multiplayer Compatibility

Positions of planets and stars are calculated from the world time, therefore other players on the same world will see the same stars and planets as you. This won't be the case if you change certain settings, such as "year length" or most settings in the "Planets" category.

Overlays and Constellations

In the "Overlays" categories, you can enable overlays rendered over the sky. The "Show Constellations" option, helps you see constellations by drawing lines between stars, showing which stars make up each constellation. There are also options to show a grid or the ecliptic.

Live Mode

Live Mode uses the current real-life planet positions. It can also use irl time of day, but you have to set a longitude and latitude to use.

Globe Mode

Instead of fixed longitude and latitude, you can have it change based on your coordinates in the MC world.

Serene or Fabric Seasons

Astrocraft automatically syncs to these mods' config files, so the seasons line up properly.

Default config Serene Seasons:

• "Year Length": 96

Default config Fabric Seasons:

• "Year Length": 112

Minor Compatibility Issues

Enchanced Celestials

Blood moons will not coincide with Astrocraft lunar eclipses, you may want to disable astrocraft eclipses to avoid confusion.

Ad Astra

Astrocraft's skies won't show up on other planets. There is a mod by mynameisjeffitowastaken to fix this, which also automatically changes the Observing Planet option to match your current planet.

Shaders

May have a lot of visual bugs, such as duplicated suns and moons, ugly stars, etc.

Fixable Compatibility Issues

Please read through this section if you use other mods, especially if you are a modpack creator.

BadOptimizations

Set "enable_sky_angle_caching_in_worldrenderer" to "false" in the BadOptimizations config file at "config/badoptimizations.txt" Otherwise, the sun and sky will move back and forth in weird directions.

AdditionZ

Disable AdditionZ's Polar Star, also messes up the sky.

Incompatible

These mods will probably not work or crash with Astrocraft:

• Fabric Skyboxes
• Blinking Stars

Forge

Install Sinytra Connector if you want to it use with forge or neoforge.