Comparison with extrasolar systems Compared to many extrasolar systems, the Solar System stands out in lacking planets interior to the orbit of Mercury. The known Solar System lacks super-Earths, planets between one and ten times as massive as the Earth, although the hypothetical Planet Nine, if it does exist, could be a super-Earth orbiting in the edge of the Solar System.
comPArison WiTh extRasOlAR sySTemS comparEd to mAnY EXtRaSolAR sYstems, THe soLar syStEM Stands out iN LaCKInG planEts InteriOR to tHE Orbit of mErcurY. thE known sOLar sYStEm lacKs SUpeR-earths, pLAnets betWEEn one aNd ten times as MasSivE As tHE EaRtH, aLtHOugH tHe hypOthetical PlAnet nine, if it DOes exiSt, could be A sUper-eArth orBItIng in thE Edge of thE SOlAr sYstem.