I am a huge fan of the sci fi/speculative fiction trope where a mysterious entity/phenomenon appears on Earth and the understanding of its presence is the plot. Suggestions?

Examples are:
Annihilation (Bigger fan of the movie than the book to be honest)

Story of your Life (Arrival the motion picture)

Sleeping Giants (Sylvain Neuvel)

Spin (by Robert Charles Wilson).

The Harbinger (by Olan Thorensen).

Anomoly (by Peter Cawdron )

Ascension (by Nicholas Binge)

by KBlake1982