svarogteuse t1_jba9uin wrote on March 7, 2023 at 4:32 PM

There is a forum for this /r/worldbuilding. Many of these questions are asked there in the context you are looking for.

The short answers are:

We don't usually consider a satellite to have any influence on geography, geology or climate other than tides. A satellite and the tides are usually considered necessary for the evolution of life.

>Also, what would happen if a natural satellite suddenly appears around a planet that did not had one ?

Largely depends on the mass and distance.

>creating a new Mars-like (like red desert planet) satellite directly from the crust of the original Earth-like planet they lived on

Ripping that much mass from the planet is much more devastating than the moon itself.

>it destroys Pangea and reshapes the lands.

It reshapes the planet. Gravity isn't going to tolerate a missing chunk and gravity is going to force the planet back into round or nearly so. Massive devastation as in earthquakes beyond imagination until its settled.

Im_riding_a_lion t1_jbadf65 wrote on March 7, 2023 at 4:55 PM

Maybe not in the same scale as plate tectonics, but the shaping of continents is effected by tides causing coastal erosion and accreciation.

svarogteuse t1_jbaeb4f wrote on March 7, 2023 at 5:01 PM

No where near the same scale as plate tectonics. On the local level tides will cause erosion but when we do modeling of tectonics with something like gplates you aren't modeling the small time scale erosionable bits (like the coastline) anyway you are modeling masses of rock. The fine details that would be effected by tidal erosion are just left to artistic interpretation once you make more detailed maps.