Could an advanced alien civilisation move its star to another part of the galaxy? Alexander Svoronos at Yale University has devised a way to do it, perhaps to avoid a calamity such as a nearby supernova. Assuming the star to be moved is the same mass as the sun, it would involve placing a large structure, weighing at least a fifth the mass of our moon, as close as 10,000 kilometres from the star. The gravitational pull of the object, although small, would drag the star towards it, producing acceleration. The structure would have thrusters, allowing it to move and pull the star along with it. Svoronos estimates that this acceleration could enable speeds of 0.1 per cent the speed of light in 5300 years.
