This scatterplot compares Star Wars planets by their diameter and population, with each planet’s diameter also determining the size of its circular mark. The visualization uses D3 v5’s `scaleLinear` for the x- and y-axes and `scaleSqrt` for the radius encoding, rendering the SVG with circles. A size legend encodes the diameter scale, and data are loaded from `planets.json`. Axis tick labels are formatted using D3’s `format` function.