Dr Kirsten Banks on Instagram: "What if the Sun exploded? Don’t panic — the Sun can’t go supernova and has about 4 billion years left. But hypothetically… what would happen to the Solar System? If a star like the Sun could explode, it would send out a blast of material moving at several per cent of the speed of light. At around 5% light speed, that blast would reach Earth in under three hours — and it would wipe out all life instantly. The planet itself, though? Earth’s rocky core might survive.