You don't need to terraform a planet in order to inhabit it. Also, not all disasters are easily managed or predicted. Hypothetical virus with long incubation pe

You don't need to terraform a planet in order to inhabit it. Also, not all disasters are easily managed or predicted. Hypothetical virus with long incubation period that spreads quietly to almost every human on Earth before giving any symptoms could pose a huge danger. There are other scenarios where survival of civilization is doubtful or reconstruction is very difficult without off-world help. Given high stakes directing 1% of human energy into the long term goal of expanding our habitat beyond a single planet seems like a reasonable hedge. Not sure where the figure of 27kly comes from. Depending on how you measure it our solar system is ~200 AU or ~28 light hours across (for comparison 1 ly is ~63241 AU). Our galaxy is ~100kly across and it contains hundreds of billions of stars.