Because the dust in the images is so fine it was impossible to track any individual grains. Instead, they used the top of the dust cloud as their marker. Tracking the movement of the dust cloud clearly shows characteristic rooster tails and not the simple parabolic arc of a dust cloud we would see produced by a rover driving through, say, dust on Earth. This specific rooster tail shape is contingent on the lunar environment: the initial velocity of dust particles based on the rover’s speed, the gravitational field strength that is one-sixth what we have on Earth, and the complete lack of air resistance because the Moon has no appreciable atmosphere. Turning this visual data in to formulas allowed Hsu and Horányi to plot the movement of dust on a graph, turning the Grand Prix’s rooster tails into a mathematical visualization.