The technology required for colonizing ‘a second Earth’ would be easier to develop on the moon  The idea of colonizing another planet as either a contingency against a future extinction event or simply as an area for growth. Extinction events are considered to be any event which destroys over 50 per cent of life on Earth and there are believed to have been five of them in the last 540 million years. [i] It is in the nature of such an event that the warning we would have of such an event would not be sufficient to develop the technology required to relocate to another planet and so, by definition that technology needs to be developed when there is not the need. Taking global warming as an analogy, we now know that we should have been changing our lifestyles and economic models back at a time when virtually nobody believed that it was a reality. The moon could be used to develop biosphere and other technology which could be used in such a future colonization.  [i] Sanders, Robert, ‘Has the Earth’s sixth mass extinction already arrived?’, UC Berkeley News Center, 2 March 2011,