Looks like there’s a lot more junk floating around in space than we knew about before.
For a good while I’ve complained about the “new” definition of planet that included the “clears local region” of debris. That’s the rule that got Pluto demoted to minor or dwarf planet. The big problem I’d seen was that this means planets can come and go as debris comes and goes. When our moon formed, we were not a planet, until the debris was “cleared” and then we were again. Then there’s the Trojans in the orbit of Jupiter. Asteroids that orbit in the same orbit as Jupiter, but before and after it at stable points. Not exactly “cleared”…
Well, now there’s a new problem. Seems Mercury and Venus both orbit inside a ring of debris. Dust and such. Likely originating from some bits of crap co-orbiting with them.
But doesn’t that mean they have not “cleared the nearby area” of debris? By the “new” definition, doesn’t that make Mercury and Venus no longer planets? Hmmm? (Hey, I didn’t make that daft rule. Heck, I even said it was daft as soon as I saw it…)
Things can be graviationally broken up at the Roche limit. Asteroids and comets fly all over the place and can cause a big chunk of “debris” to suddenly show up and than are you no longer a planet? We orbit through the debris field of Comet Encke (who’s arrival and breakup some 20,000 years or so ago likely resulted in the Younger Dryas impact event along with several other major Earth catastrophes) so are WE really clear of debris?
Hopefully this “issue” with Mercury & Venus will help get Pluto put back as a planet AND get some of the other KBO planet sized objects accepted as well.