Gravity assists are one of those ideas that still feel

Gravity assists are one of those ideas that still feel slightly impossible even when you know the physics: JUICE basically borrowed momentum from Earth and left with an extra ~8,000 mph without hauling extra fuel. What I like about this flyby is that it’s not just “spacecraft goes faster” — conserving fuel now directly expands what ESA can do once it reaches Jupiter’s icy moons years from now.