Jetsam

Tropes:

Adaptational Villainy: While Murtry headshots one of the colonists in the book as well, it comes after A. He's made a public speech that he would do exactly that in response to threats to his people, B. The reader has already seen that the victim is in fact the guy who blew up Murtry's ship and C. Murtry has the man confirm outright that he's threatening before he takes the shot. None of that is the case in the show, making it look more like Murtry is homicidally overreacting to a taunt. A flashback later reveals that a small team of colonists had sabotaged the landing platform, though it was supposed to have happened well before the ship was due to land, but they came down early - and although there was an attempt to disarm it by one of the team, the rest decided that that they were fine with killing the Inners arriving.
Boom, Headshot!: Murtry takes the first remotely justifiable reason to murder one of the colonists this way.
Never Accepted in His Hometown: Bobbie realizes that the rest of Mars is always going to view her as a traitor.
Time Abyss: The alien structures on the planet are calculated to be approximately 1.5 billion years old.