太阳系SolarSystemsolarsystemconsistsoftheSunandtheothercelestialobjectsgravitationallyboundtoit:theeightplanets,their165knownmoons,[1]threedwarfplanets(Ceres,Pluto,andErisandtheirfourknownmoons),andbillionsofsmallbodies.Thislastcategoryincludesasteroids,Kuiperbeltobjects,comets,meteoroids,andinterplanetarydust.Inbroadterms,thechartedregionsoftheSolarSystemconsistoftheSun,fourterrestrialinnerplanets,anasteroidbeltcomposedofsmallrockybodies,fourgasgiantouterplanets,andasecondbelt,calledtheKuiperbelt,composedoficyobjects.BeyondtheKuiperbeltliesthescattereddisc,theheliopause,andultimatelythehypotheticalOortcloud.