That's what bankers Goldman Sachs reckon, anyway – and several companies are now vying to be the first into space. NASA estimates that the total value of asteroids out there could be up to $700 quintillion – equivalent to £75 billion each for us here on Earth. Several companies are now buidling the machines which will take us there – including Deep Space Industries, which is building a steam-powered thruster for spacecraft, the Guardian reports. British company AMC (Asteroid Mining Corporation), hopes to send tiny spacecraft out to grab platinum (common in asteroids, and very pricey on Earth) and then use the metal to finance bigger missions. 

American companies such as Planetary Resources – backed by Titanic director James Cameron – are already planning to send robotic vehicles to mine precious metals and rare resources from asteroids.