I couldn’t say as I haven’t played Starfarers before. I’m sure mechanically there are some similarities at least. Even so, I highly recommend Star Trek Catan!!
Looking at Star Trek Catan, it looks like a themed Catan but with Support cards, which is a great addition to the game. Not sure if there’s anything I’m missing since I haven’t played it. I’ll have to give it a try, and I could probably get my parents to give it a go since it’s Star Trek themed.
Starfarers personally is my favorite. It’s very different from regular Catan. First difference is your map is longer a perfect hexagon and is a bit bigger. You start at the bottom of the map on your starting planets and you have 2 colonies and 2 colony ships like you do in Star Trek. You don’t however have to build “roads”, instead you have a rocket you shake and move your ships according to the result of the shake plus added speed for boosters on your ship. You can spend resources to add more boosters, or guns, or cargo crates to your ship for better bonuses.
You can explore planets and see if you like the resources it has and settle them. You can also build trade ships that let you dock with alien trading outposts to acquire those Support cards you have in Star Trek.
The thing that really makes the game stand out however is the event deck. On some rolls you trigger random events involving alien species you can trade with, or attacks by pirates, or black holes you discover. Planets you explore may also have pirate bases you have to clear before you can settle the planet, or the planet may be frozen and require terraforming.
I really enjoy it, and the 5-6 player expansion handles the added players well by making 2 opposite people take turns simultaneously.