This episode takes place from November 2006 to March 2007.
Modern scientific theory suggests that Mars may have held an ocean between 4.1 to 3.8 billion years ago. Thus, when Colonel Wilder is told by the Martian ghost that, in his time, there is a vast sea visible from his city, this indicates that the two are possible speaking across billions of years and that the Martian civilization may be almost as old.
When Colonel Wilder has a conversation with the Martian Ghost, the Martian refers to his planet as "Tyr". Tyr was a War God from ancient Germanic / Norse mythology. Our name for the planet Mars comes from the name of a War God from ancient Roman mythology.
An 11-year-old Laurie Holden, stepdaughter of Michael Anderson (director of the series), appears as Marie Wilder, the young daughter of Colonel John Wilder (Rock Hudson).