One thing that I only learned recently is that a lot of terraforming is very destructive. So you would NOT want to colonize a planet first and then terraform i

One thing that I only learned recently is that a lot of terraforming is very destructive. So you would NOT want to colonize a planet first and then terraform it. Instead you would terraform it first. Terraforming Mars for example could involve sending a large number of comets to crash to the planet. If there were existing colonies on the planet, they might be destroyed by the impacts or be inundated by the torrential rains. Isaac Arthur has some thought provoking videos about this.