To get people to notice, you're often looking for that one thing that boggles the mind. And sometimes, nature does that for you on a cosmic scale. Matt Strassler has one such example:
Visualize that if you can: objects a few dozen miles (kilometers) across, a few miles (kilometers) apart, each with the mass of the Sun or greater, orbiting each other 100 times each second.
All I can say is, wow.