The mod is entirely client-side and designed for helping with world-building and immersion, it is encouraged you think of lore about all the constellations you draw and planets you name!
Planets and stars will be the same for all players on a particular world, and are generated randomly (and largely scientifically accurately) per world, and you can easily share constellations between players using a client-side command
To interact with the cosmos there are three spyglass modes: vanilla, constellation (amethyst), and star (emerald), these are cycled with the pick block button (middle click) while zoomed in.
Constellation mode allows you to draw constellations by holding the attack button (left click) and drawing between stars, as well as being able to select constellations
Star mode allows you to select stars and planets, note that comets are referred to as planets when using commands
Once an object is selected you can name it with /sga:name <name>, or get useful information with /sga:info, you can also get the information of a specific object without selecting it by following the suggestions after typing /sga:info <x>
If you're playing on a multiplayer server, you can use /sga:share or /sga:share <x> to share the currently selected or specified object respectively, this gives you a code you can send in chat or /message to someone directly, which allows them to easily add a constellation or name of a planet or star on their side, provided they have the mod too, of course. For an even smoother experience, you can use Spyglass Astronomy Sync, although that needs to be on the server too
All the client-side commands can be seen by looking at the suggestions after typing /sga:, or by looking at the list on the github readme
