Kuwo wonke umlando, ososayensi abaningi bebelokhu bephakamisa imibono ehlukahlukene mayelana nokwakheka kwamaplanethi, indawo yonke kanye nesimiso sonozungezilanga. Kulokhu, sizokhuluma ngethiyori yesimanje ye amaplanethi. Lolu uhlobo lwethiyori ephakamisa ukuthi amaplanethi akhiwe nge-nebula yegesi nothuli lwezinkanyezi.
Kulesi sihloko sizokutshela ngezici zethiyori yesimanje yamaplanethi, owayiphakamisa nokuthi ibe namiphi imiphumela emhlabeni wesayensi yezinkanyezi nesayensi.
Ithini inkolelo-mbono yamaplanethi?
Ithiyori ye-planetesimals iyinkolelo-mbono ezama ukuchaza ukuthi amaplanethi akhiwe kanjani ohlelweni lwethu sonozungezilanga nakwezinye izinhlelo zezinkanyezi. Ngokwalo mbono, amaplanethi avela efwini legesi nothuli elibizwa ngokuthi i-protoplanetary nebula.
Okokuqala, inkolelo-mbono ibeka ukuthi i-protoplanetary nebula iwumphumela wefu elikhulu lamangqamuzana eliwa ngaphansi kwethonya lamandla adonsela phansi. Njengoba ifu lifinyela, liqala ukuzungeza ngokushesha, okuholela ekwakhekeni kwe-accretion disk ezungeze inkanyezi esencane ebizwa ngokuthi i-progenitor star.
Ngaphakathi kwaleli diski lokwenyuka, izinhlayiya ezincane zothuli neqhwa, ezaziwa ngokuthi ama-planetesimals, ziqala ukungqubuzana futhi zinqwabelane ngenxa yamandla adonsela phansi. Lawa maplanethi ayisisekelo samaplanethi azayo. Njengoba ziqhubeka zikhula kusukela ekungqubuzaneni nasekuhlanganeni, amaplanethi aphenduka ama-protoplanet, akha imizimba yamaplanethi.
Esinye sezici eziyinhloko zama-planetesimals ubukhulu bawo. Lezi zinto zingaba ngosayizi ukusuka kumakhilomitha ambalwa ukuya emakhulwini amakhilomitha ububanzi. Ubukhulu bayo kanye nokwakheka nakho kungahluka, kuye ngendawo engaphakathi kwediski yokukhula kanye nezinto ezitholakalayo.
Ngaphezu kwalokho, inkolelo-mbono yama-planetesimals iyachaza Akhiwa kanjani amaplanethi anamadwala namaplanethi egesi?. Amaplanethi anamadwala, njengoMhlaba ne-Mars, akha eduze nenkanyezi engumzali, lapho amazinga okushisa ephakeme nezinto eziqinile. Amaplanethi egesi, njengeJupiter kanye neSaturn, akheka ezindaweni ezikude, lapho amazinga okushisa ebanda kakhulu futhi enegesi kanye nezinto ezineqhwa ziningi kakhulu.
Njengoba ama-protoplanet eqhubeka nokukhula, bangathwebula ukwaziswa okwengeziwe futhi ekugcineni babe amaplanethi avuthiwe. Ithiyori yePlanetesimal inikeza incazelo ehambisanayo yokuthi amaplanethi athola kanjani ubukhulu bawo, i-orbit, kanye nokwakheka kwawo.
Ubani ohlongoze lo mbono?
Ithiyori ye-planetesimals iye yathuthukiswa futhi yashintshwa ososayensi abahlukahlukene kuwo wonke umlando. Omunye wababambe iqhaza elikhulu kwaba yisazi sezinkanyezi saseFrance uPierre-Simon Laplace. Wazalwa ngo-1749. ULaplace wayaziwa ngomsebenzi wakhe kumakhenika asezulwini kanye nethiyori yamandla adonsela phansi. Izifundo zakhe mayelana nokwakheka kwesimiso sonozungezilanga kanye nokuzinza kwamaplanethi zabeka isisekelo semibono yakamuva kumaplanethi.
Omunye usosayensi obalulekile kulo mbono isazi sezinkanyezi saseSweden uVictor Safronov. Wazalwa ngo-1917, u-Safronov waqashelwa ngomsebenzi wakhe onamandla ekubunjweni nasekuziphendukeleni kwezinhlelo zamaplanethi. Uhlongoze i-planetesimal hypothesis futhi waveza ukubaluleka kwayo ekwakhekeni kwamaplanethi.
Futhi izazi zezinkanyezi UGerald Kuiper noGeorge Wetherill, yaba negalelo elikhulu embonweni wamaplanethi. UGerald Kuiper, owazalwa ngo-1905, wayeyisazi sezinkanyezi esaziwa ngocwaningo lwakhe mayelana nesimiso sonozungezilanga kanye nokwakheka kwamaplanethi. Umsebenzi wakhe waba nesandla ekuqondeni izinto zebhande le-Kuiper kanye nobudlelwano bazo namaplanethi.
Ngakolunye uhlangothi, uGeorge Wetherill wayeyisazi sezinkanyezi saseMelika owazalwa ngo-1925, futhi waphumelela emkhakheni wesayensi yeplanethi kanye ne-cosmogony. Wenza ucwaningo oluyisisekelo mayelana nokushayisana nokunqwabelana kwamaplanethi, futhi wenza amamodeli ezinombolo ukuze alingise ukuziphendukela kwawo kanye nokwakheka kweplanethi.
Ukubaluleka kwethiyori ye-planetesimals ku-astronomy
Ithiyori yamaplanethi ibaluleke kakhulu emkhakheni wesayensi nesayensi yezinkanyezi ngenxa yemithelela yayo eminingi kanye negalelo layo. Lo mbono unikeze isisekelo esiqinile sokuqonda inqubo yokwakheka kweplanethi esimisweni sethu sonozungezilanga futhi uye wabeka isisekelo sokucwaninga ukwakheka kwamaplanethi kwezinye izinhlelo zezinkanyezi. Lezi yizizathu eziyinhloko zokubaluleka kwe-planetesimal theory ku-astronomy:
- Umsuka wesistimu sonozungezilanga: Ithiyori yamaplanethi yenze kwaba nokwenzeka ukuchaza ukuthi isimiso sethu sonozungezilanga senziwa kanjani sisuka kuyi-protoplanetary nebula. Kuyasiza ukuqonda ukuthi amaplanethi, kuhlanganise nowethu, avela kanjani ezinhlayiyeni ezincane nokuthi avela kanjani ngokuhamba kwesikhathi.
- Ukwakhiwa kwamaplanethi e-extrasolar: Lo mbono awusebenzi nje kuphela esimisweni sethu sonozungezilanga, kodwa futhi ube yisisekelo ekutadisheni nasekuqondeni ukwakheka kwamaplanethi kwezinye izinhlelo zezinkanyezi. Ngokubheka nokuhlaziya amadiski e-protoplanetary azungeze izinkanyezi ezincane, izazi zezinkanyezi zithole ubufakazi bokuba khona kwamaplanethi futhi ziye zakwazi ukusho ukuthi amaplanethi akheka kanjani kulezi zifunda.
- Ukwakheka kanye nokuziphendukela kweplanethi: Ithiyori ye-planetesimals isisiza ukuba siqonde ukuthi ukwakheka nokwakheka kwamaplanethi kutholakala kanjani. Ukungqubuzana nokunqwabelana kwamaplanethi omhlaba ngesikhathi sokwakheka kwamaplanethi kudlala indima ebalulekile ekunqumeni ukwakheka kwangaphakathi nangaphandle kwamaplanethi, kanye nasekuguqukeni komkhathi nezindawo zawo.
- Ukusatshalaliswa kwamaplanethi nezinhlelo zamaplanethi: Lo mbono ube nomthelela ekuqondeni ukusatshalaliswa nokuhlukahluka kwezinhlelo zamaplanethi endaweni yonke. Kusisiza siqonde ukuthi kungani ezinye izinhlelo zezinkanyezi zineplanethi enamadwala eduze nenkanyezi yazo, kuyilapho ezinye zinemidondoshiya yegesi kude nawo. Ngaphezu kwalokho, inikeza ulwazi mayelana nokwakheka kwezinyanga nezinye izinto zasezulwini emzileni ozungeza amaplanethi.
Njengoba ubona, lolu hlobo lwethiyori lungenye yezinto ezisekelwa kakhulu emhlabeni wesayensi futhi ngenxa yalo sikuqonda kangcono ukwakheka kwamaplanethi. Ngithemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana nethiyori yamaplanethi nokubaluleka kwayo.