planets.md

• The indentation is inconsistent (2, 3, 7 spaces...)
• The names of classes are inconsistent (camelCase, snake_case, Firstletteruppercased, ...)
• There is commented-out code that could be removed
• The comments are useless as they try to describe how the code works...
  • ...and misleading, because sorted returns a sorted list, it does not sort in-place