The Somnaran Sail's main purpose is to spread life, which includes replicating itself on other worlds. The ship drops Somnapods onto other planets- these pods then analyze & repurpose the planet's resources and use them to replicate itself into a new vessel.
Here we see a scene where Humanity encounters a Somnapod for the first time.

Modeled/painted completely on my stream at

Finnian macmanus 002
Finnian macmanus recovery scene 2 callout 1