This map shows the orbits of more than 18000 asteroids in the solar system. This includes everything we know of that’s over 10km in diameter - about 10000 asteroids - as well as 8000 randomized objects of unknown size. Each asteroid is shown at its position on New Years’ Eve 1999, colored by type of asteroid. I've open-sourced all the code here in a tutorial that explains how to recreate the design.
All of the data for this map is shared by NASA and open to the public. However, the data is stored in several different databases so I had to do a decent amount of data cleaning. I’ve explained all of the steps in detail in my open-source code, but a basic data flowchart and a few initial sketches are shown below:
So one of the biggest changes I made to this data was to re-project my map from a linear scale that showed true distance, to a radial logarithmic scale. This perspective gives a lot of emphasis to the first billion kilometers from the sun, which is where most of the asteroids are in the main asteroid belt. But, it still includes the entire rest of the solar system, which means that I could include large band of Kuiper belt asteroids near the very edge of our solar system.
I also used a separate logarithmic scale to visualize the diameter of each asteroid. The sketch below shows the difference between a linear scale (on the left) and a logarithmic scale (on the right). Both are scaled so that the smallest asteroids are visible on the screen.
Instead of making each asteroid orbit the same length, I set the orbit paths to 40 years, but clipped shorter to a quarter of the orbit for the inner asteroids This helped visualize the asteroids in the outer solar system, while still keeping the inner solar system legible.
There wasn’t enough space to label every single asteroid, so I manually compiled a list of interesting asteroids, and plotted each of these in Python alongside the asteroid itself and a label line. Then I moved all of the asteroid labels by hand in Illustrator.