All the science included on our project was reviewed first by Emily Lakdawalla, Senior Editor at The Planetary Society. In many cases, some of this information was almost common knowledge for someone with Emily’s background. But even something as simple as size sometimes required double-checking for bodies recently explored such as Pluto or Ceres.
The interiors side of the blocks is where we are breaking some new ground. To gather this data required going to several sources for the most recent theories. I would even go out on a limb and say this set of blocks may be the only source where you can find up-to-date information on the interiors of all the major planetary bodies of our Solar System.
For an amazing deep dive into how all this information was gathered look at Emily’s post on her amazing Planetary Blog from May 1. Everything is outlined including scientific sources, how we selected the missions featured, and even how we chose these twenty bodies as the best representatives of the Solar System. She even reviews what the set might look like if it included 40 worlds!