In The Savage Curtain (1969), Colonel Green is featured as one of the 'evil' combatants. It is explained here why he is considered evil a century into the future. Originally, the makers wanted to establish him in Borderland (2004) as one of the key figures in the Eugenics Wars, which resulted from an attempt to genetically enhance humanity. He was re-written as a notorious military leader during World War III, who killed off victims of radiation poisoning afterwards in order to keep humanity "pure".
Paxton comments that he was studying history before his father died, leaving him the mining facility on the Moon. At the time of filming, the actor playing him, Peter Weller, was finishing a PhD in Italian art history at UCLA, and preparing to host Engineering an Empire (2005) on The History Channel. Most people know him from his most popular film role playing the title character in RoboCop (1987).
Although Mars was previously seen from space, this is the first time that the surface of the planet is shown in Star Trek. A holographic version of the planet surface was seen in Lifesigns (1996).
The character name of the United Earth news reporter, Gannet Brooks, is a reference to Gannett Corporation, the real world 20th century media company that publishes such newspapers as USA Today, among many others.
The events of this episode take place exactly a day after those of In a Mirror, Darkly, Part II (2005).