New theoretical models have strengthened the case that immense, energy-harvesting structures orbiting their host stars could exist in principle in distant stellar systems. With the right engineering precautions, calculations published in Monthly Notices of the Royal Astronomical Society, carried out by Colin McInnes at the University of Glasgow, show that both stellar engines and Dyson bubbles can become gravitationally stable, allowing them to tap into the vast amounts of energy emitted by their host stars.