This scatter plot visualizes the diameters of planets and their moons, with each dot colored by its base planet name and labeled with an emoji on the x-axis. The visualization uses D3.js v7 to load CSV data from a GitHub gist, render an SVG with d3.scaleBand and d3.scaleLinear axes, and display tooltips showing type, diameter, and moon count. Hovering over a dot reduces its opacity to highlight the data point.