When this first cropped up, I asked a few geologists and not even they know what a continent is. As near as I could tell, they preferred we stop using the term.

An 8 day week would actually alleviate the pressures of modern society. Give people another day of rest. We have had enough efficiency increases that the extra day of rest wouldn't 'break the efficiency bank' so to speak. This would probably be in lieu of a basic income. I'd much rather have more time than some baseline of economic necessities but that is IMHO.

There are actually two hypothesized planets orbiting beyond Neptune. Planet Nine is pretty well accepted as a reasonable theory in the scientific community, sufficient enough to dedicate millions of dollars worth of observing time on some of the biggest telescopes on Earth to try to look for it. Planet Nine is expected to be around 10 Earth masses and have an orbit that reaches out to several hundred times farther from the Sun than Earth (AUs). The evidence pointing to a "Planet 10" is not nearly as strong but intriguing nonetheless, it's hypothesized to be a roughly Earth mass planet (or less) orbiting only maybe 2-3x as far from the Sun as Neptune