Infographics and interactives abound to show you just show BIG space really is—and how small the things that inhabit it are. Relatively speaking, of course. But almost none of us have any real frame of reference to help us understand objects at this scale. Often, the planets and moons of the solar system are put into scale with sports equipment analogies: If the Earth were the size of a basketball, the Moon would be the size of a tennis ball!
Over at xkcd, cartoonist Randall Munroe came up with an eye-opening way to represent many of the medium-sized objects in our solar system. Reproduced above, Munroe's map flattens out the Earth and the Moon, along with a host of other planets and moons, easily showing how they really compare. It's surprising to see that Ganymede, the largest moon in the solar system (one of Jupiter's), is about the same size as Europe and Africa. Mars and Mercury, meanwhile, are surprisingly close in size.
Even here, though, the complexities of representing the vast range of sizes of things in the solar system is apparent. While all of these planets and moons are nicely stitched side-by-side, they'd be little more than a speck on Jupiter's flattened face.