> Well the number one threat to Earth is an impact event. Challenged— that’s the number one natural threat to (human civilization on) Earth. Or maybe the numbe

> Well the number one threat to Earth is an impact event. Challenged— that’s the number one natural threat to (human civilization on) Earth. Or maybe the number one threat assuming we survive the next thousand years. The number one threat at this moment is deliberate annihilation of the ecosphere by a very small number of insane humans. The number two threat is negligent annihilation of the ecosphere by a plurality of merely shortsighted humans. Not only is a Mars colony uniquely susceptible to these existential risks, the process of building one could plausibly make them worse. Space folks like to talk a lot about how the technology you use to survive in space is technology you can use to live better on Earth. They don’t like to talk about how the technology you use to get to space is the same technology you use to murder human civilization anywhere it hides. I wonder why.