So you thought your fridge magnet was pretty neat. You obviously haven't met the most powerful magnet known to man. Magnetars are neutron stars, left over from the death of a giant star. Their density and rapid rotation (several times per second) enormously increases the power of their magnetism. If you placed a magnetar where the Moon is, 400,000 kilometres away, it could still wipe your credit cards and rip spoons out of your pockets.