▁de void ▁of ▁any ▁form ▁of ▁life . ▁They ▁will ▁continue ▁to ▁orbit ▁their ▁star , ▁their ▁speed ▁slow ed ▁due ▁to ▁their ▁increased ▁distance ▁from ▁the ▁Sun ▁and ▁the ▁Sun ' s ▁reduced ▁gravity . ▁Two ▁billion ▁years ▁later , ▁when ▁the ▁Sun ▁has ▁co o led ▁to ▁the ▁ 6 0 0 0 – 8 0 0 0 K ▁range , ▁the ▁carbon ▁and ▁o xygen ▁in ▁the ▁Sun ' s ▁core ▁will ▁free ze , ▁with ▁over ▁ 9 0 % ▁of ▁its ▁remaining ▁mass ▁assuming ▁a ▁cry st all ine ▁structure . ▁Event ually , ▁after ▁roughly ▁ 1 ▁quadr ill ion ▁years , ▁the ▁Sun ▁will ▁finally ▁ce ase ▁to ▁sh ine ▁altogether , ▁becoming ▁a ▁black ▁d war f . ▁ ▁Gal actic ▁interaction ▁ ▁The ▁Sol ar ▁System ▁travel s ▁alone ▁through ▁the ▁Mil ky ▁Way ▁in ▁a ▁circular ▁orbit ▁approximately ▁ 3 0 , 0 0 0   light ▁years ▁from ▁the ▁Gal actic ▁Centre . ▁Its ▁speed ▁is ▁about ▁ 2 2 0   km / s . ▁The ▁period ▁required ▁for ▁the ▁Sol ar ▁System ▁to ▁complete ▁one ▁revolution ▁around ▁the ▁Gal actic ▁Centre , ▁the ▁gal actic ▁year , ▁is ▁in ▁the ▁range ▁of ▁ 2 2 0 – 2 5 0 ▁million ▁years . ▁Since ▁its ▁formation , ▁the ▁Sol ar ▁System ▁has ▁completed ▁at ▁least ▁ 2 0 ▁such ▁revolution s . ▁ ▁Vari ous ▁scient ists ▁have ▁spec ulated ▁that ▁the ▁Sol ar ▁System ' s ▁path ▁through ▁the