Eminent scientists such as Stephen Hawking have endorsed the idea of establishing colonies on the Moon or other planets so humanity would survive any disaster that wiped out life on Earth. Yet evacuating all 6.7 billion Earthlings would take the equivalent of a billion space shuttle launches. Even if we could launch 1000 shuttles a day, it would still take 2700 years to move the whole planet’s population.

Then there’s the matter of taking care of people once they reached their new home. Moving to any other planet would require “terraforming” it to provide food, water and oxygen to support colonists. Why not bring our own planet along with the resources we would need?