How about this depressing scenario:
We never develop technology capable of accelerating massive ships past lightspeed, even in vacuum. Furthermore, we never figure out how to make viable energy weapons or energy shielding. Eventually we figure out how to make self-sustaining colony vessels that can travel to worlds we think are capable of sustaining life.
One of our vessels finds a world inhabited by a sapient reptilian species who have completely overcome their warlike past, have a truly utopian society set up, and are just on the cusp of developing extragalactic travel... so they're maybe a few centuries of development behind the ship that reaches them.
Unfortunately, the ship is full of human colonists armed to the teeth and expecting their own world. Worse than that, they're the 30th generation to live aboard that vessel. They don't know anything they weren't taught by the ship's computers... and there's no contingency plan for contact with a sapient species (typical government contractor company).
Contact is made, understanding is nowhere to be found, and our people wind up opening fire because the natives are big, ugly, scary lizard-people making threatening gestures. A war ensues, and because of our superior weapons technology, our colonists win, driving them off of one continent. What was once a utopian society devolves into a species of xenophobic revolutionaries. About the time our colonists' first transmissions from the planet reach Earth, the lizard people have already taken back their continent, and not one human remains alive on the planet.
We never develop technology capable of accelerating massive ships past lightspeed, even in vacuum. Furthermore, we never figure out how to make viable energy weapons or energy shielding. Eventually we figure out how to make self-sustaining colony vessels that can travel to worlds we think are capable of sustaining life.
One of our vessels finds a world inhabited by a sapient reptilian species who have completely overcome their warlike past, have a truly utopian society set up, and are just on the cusp of developing extragalactic travel... so they're maybe a few centuries of development behind the ship that reaches them.
Unfortunately, the ship is full of human colonists armed to the teeth and expecting their own world. Worse than that, they're the 30th generation to live aboard that vessel. They don't know anything they weren't taught by the ship's computers... and there's no contingency plan for contact with a sapient species (typical government contractor company).
Contact is made, understanding is nowhere to be found, and our people wind up opening fire because the natives are big, ugly, scary lizard-people making threatening gestures. A war ensues, and because of our superior weapons technology, our colonists win, driving them off of one continent. What was once a utopian society devolves into a species of xenophobic revolutionaries. About the time our colonists' first transmissions from the planet reach Earth, the lizard people have already taken back their continent, and not one human remains alive on the planet.