I don't think this topic has been discussed before but yesterday I read something to the effect that Trump wants a human mission to Mars to be completed within his presidency.
With that being said, the Watchtower teaches that what started on Earth ends on Earth, in other words, the Fall of Adam and Eve would end with the passing of the 1,000 year Millennial Reign when Christ destroys all his enemies, rebellious "perfect" humans, and the Devil and his demons who are let out the abyss for a short while. He then hands the Kingdom back to his Father.
An elder in my old congregation once told us during a public talk that he was an ardent astronomer but then referenced the scripture where it says, "The Earth he has given to the sons of men" (Psalms 115:16). He told us that man was breaking God's laws by leaving the Earth that Jehovah had given to humans and landing on the moon.
Acts 17:26 says "He made from one man every nation of mankind to live on
all the face of the earth, having determined their appointed times and
the boundaries of their habitation."
My point is, that with all of Biblical prophecy focused on this planet, Earth, (people living at that time of writing had no idea the Earth was even a sphere), what would become of Bible prophecy once man really does land on Mars and establish a colony?