Some druids are less interested in terrestrial nature and more in the secrets hidden in the night sky. After all, the world stretches beyond just the terrestrial, so why shouldn't there gaze wander upwards as well, not to menthion the effects stellar bodies have on the world. The moon drives the tides, starts plot out destinies and hidden knowledge, and astrologers seek it all, wreathed In the soft glow of starlight.
At 1st level you learn the guidance cantrip if you do not already know it. It is especially effective and grants a 1d6 expertise die instead of a 1d4.
In addition, when you select this archetype at 1st level you cannot become lost by nonmagical means as long as you can see the night sky, and while able to do so you gain an expertise die on Survival checks.
Also at 1st level you add the guiding bolt spell to your druid list. You always have it prepared and it does not count against your number of prepared spells.
At 6th level you add the augury and divination spells to your druid spell list. When casting either of these spells, you may ignore an accumulated failure chance as long as you can see the night sky. You may do so a number of times equal to half your proficiency bonus per spell and regain all expended uses when you finish a long rest.
At 10th level, when you cast a spell that summons beasts or fey, you may instead summon a manifestation of a constellation instead. The creatures summoned have resistance to radiant damage and damage from non-magical weapons, Truesight, and their attacks all deal an additional 1d6 radiant damage. You may also gain the same benefits when you use a Wildshape. You may only apply these benefits once per short or long rest.
At 14th level, you gain a grade 4 Sacred Grove stronghold. In addition to the normal benefits it also contains a circle of standing stones that map the stars. You always have the divination and augury spells prepared and they do not count against your number of prepared spells. While in your Sacred Grove you may cast each of these spells once per long rest with out expending a spell slot, and in your grove you always count as being able to see the night sky even if you cannot (if you are blind, if it is daytime, etc.)