itan ) ▁orbit ing ▁H IP ▁ 5 7 0 5 0 ▁b . ▁While ▁it ▁is ▁not ▁out ▁of ▁the ▁question ▁that ▁H IP ▁ 5 7 0 5 0 ▁b ▁could ▁har bor ▁a ▁moon , ▁and ▁that ▁moon ▁would ▁thus ▁be ▁in ▁the ▁liquid ▁water ▁H Z ▁of ▁the ▁parent ▁star , ▁an ▁object ▁with ▁only ▁ 1 / 5 th ▁of ▁the ▁mass ▁of ▁Mars ▁in ▁the ▁liquid ▁water ▁H Z ▁is ▁probably ▁not ▁a ▁particularly ▁good ▁prospect ▁for ▁habit ability ▁from ▁various ▁stand points . ▁In ▁any ▁case , ▁direct ▁detection ▁of ▁such ▁a ▁moon ▁would ▁be ▁extremely ▁challeng ing ." ▁ ▁Paul ▁Gil ster ▁of ▁the ▁T au ▁Zero ▁Foundation ▁has ▁commented : ▁" B ased ▁on ▁our ▁knowledge ▁of ▁the ▁gas ▁gi ants ▁in ▁our ▁own ▁Sol ar ▁System , ▁it ’ s ▁a ▁natural ▁supp osition ▁that ▁this ▁is ▁a ▁world ▁with ▁mo ons , ▁and ▁if ▁so , ▁their ▁location ▁in ▁the ▁habit able ▁zone ▁draw s ▁in ev itable ▁compar isons ▁with ▁fict ional ▁world s ▁like ▁P and ora ." ▁ ▁Gil ster ▁suggested ▁that ▁an ▁Earth - s ized ▁moon ▁could ▁exist ▁around ▁the ▁planet ▁if ▁it ▁were ▁captured ▁after ▁forming ▁independently . ▁ ▁A ▁second ▁planet ▁was ▁sus pected ▁based ▁on ▁additional ▁radial ▁velocity ▁measurements ▁made ▁at ▁W . ▁M . ▁Ke ck ▁Observ atory , ▁this ▁was ▁confirmed ▁by ▁measurements ▁taken ▁at ▁Cal ar ▁Al to ▁Observ atory . ▁ ▁References ▁ ▁Category : M - type ▁main -