Snapchat’s Friend Solar System is a Snapchat+ feature that shows your position among someone’s Best Friends using planets.
The order runs from Mercury to Neptune, with Mercury representing the first position and Neptune the eighth.
For a straightforward explanation of the planet meanings and their order, https://snapchatplanets.co.uk/ provides a useful reference.
The ranking reflects Snapchat interaction rather than necessarily measuring the strength of a real-life friendship.
Have you found the planet system helpful for understanding your Snapchat connections?