in Dataviz

Plotting Moons in a D3 Scatterplot

Ever wondered what is the relation between a moon’s orbital radius (around its parent planet) and its diameter? Well, here’s a very simple scatterplot that illustrates this astronomy themed task. Mouse-over events on each dot display a picture of the moon (if such a thing exists) and some more info, all sourced from Wikipedia.

Notice how smaller moons tend to cluster very far or very close to their planet, while the larger satellites are located at intermediate orbits. The exception seems to be Saturn’s Hyperion, which is a very odd looking moon by the way. Also, satellites with a diameter smaller than 300 km are oddly shaped, like space potatoes (insufficient mass/gravity to reach a more spherical shape I suppose). Conclusion: astronomy rocks!