Vazhinji vanopokana kuti misiyano iripo pakati pemapuraneti makuru echando nemapuraneti makuru egasi inosvika pakuumbwa kwawo. Solar System inofungidzirwa kuti yakaumbwa kubva kubhora hombe rinotenderera regasi neguruva rinozivikanwa se presolar nebula. Zvizhinji zvegasi re nebula, kunyanya hydrogen ne helium, zvakaumba Zuva, uye zviyo zveguruva zvakaunganidzwa pamwechete kuti zviumbe mapuraneti ekutanga. Sezvo mapuraneti akakura, mamwe acho akazounganidza zvinhu zvakakwana kuti giravhiti yavo ibate gasi rakasara re nebula. Gasi rakawanda ravakabata, rakawedzera kukura; zvakakura zvavakava, rakawedzera gasi kusvikira vasvika padanho rakakosha, uye saizi yavo yakatanga kuwedzera exponentially. Mapuraneti makuru echando, aine mashoma mashoma epasi yegasi nebula, haana kumbobvira asvika padanho rakakosha.
hofori dzeaizi dzakaumbwa dziri pedyo neZuva kudarika nzvimbo dzadzo dzazvino