We've come a long way, baby
Checking out some of the recent images from the Astronomy Picture of the Day website, I was struck by this plot of known objects in the inner solar system. First of all, I love a graph with a ton of data in it (thank you, Edward Tufte). But second, I'm gobsmacked by the sheer amount of knowledge that this graph summarizes. Especially when you compare it to the state of knowledge in Copernicus's drawing below.
Credit & Copyright: MPC,CBAT,Harvard CfA,IAU