minus-squareAkt0@reddthat.comtoscience@lemmy.world•'Planet Y' theory hints at hidden Earth-size world lurking in the solar system — and it could be much closer to us than 'Planet Nine'linkfedilinkEnglisharrow-up14·9 days agoIt seems as though Planet Y is an alternate theory to Planet X, which are both hypothetical 9th planets. The headline makes it sound like they theorize 10 planets already. linkfedilink
minus-squareAkt0@reddthat.comtoscience@lemmy.world•'Planet Y' theory hints at hidden Earth-size world lurking in the solar system — and it could be much closer to us than 'Planet Nine'linkfedilinkEnglisharrow-up8·edit-29 days agoUranus is the 7th planet, followed by Neptune. Wikipedia on Planet 9 edit: added Planet 9 article linkfedilink
It seems as though Planet Y is an alternate theory to Planet X, which are both hypothetical 9th planets. The headline makes it sound like they theorize 10 planets already.