Why humans must leave Earth

Abstract

Automated probes offer a cheaper and safer way to explore the solar system, they say - just look at the success of NASA’s Mars Rovers and the Huygens probe on Titan. In the 16th century, the Polish polymath Nicolaus Copernicus suggested that we do not occupy a special place at the centre of the universe, but rather inhabit one of a number of planets circling the sun. Gerard O’Neill, a physicist and founder of the Space Studies Institute in Princeton, New Jersey, calculated that to establish a space colony inside a sealed biosphere, capable of supporting life by recycling air and water, would take at least 50 tonnes of stores per person.