Udindo wa Mphamvu Yokoka Pakupanga Mapulaneti
Mphamvu yokoka ndiye "wopanga zinthu" wamkulu amene amapanga dongosolo la dzuwa ndi mapulaneti ake. Mphamvu imeneyi imagwira ntchito mwakachetechete koma mosalekeza, kukoka zinthu kuchokera ku fumbi kupita ku miyala ikuluikulu pamodzi kukhala mapulaneti okhazikika ozungulira nyenyezi. Popanda mphamvu yokoka, mpweya wa cosmic ndi fumbi sizingagwirizane kukhala zinthu zazikulu; zikanakhalabe zomwazikana mwachisawawa mumlengalenga. Kuti timvetse momwe mapulaneti amapangikira, tiyenera kufufuza momwe mphamvu yokoka imagwirira ntchito kuyambira pachiyambi cha dongosolo la mapulaneti mpaka kukula kwake.
1. Mitambo ya mamolekyu ndi chiyambi cha kugwa kwa zinthu
Kupangidwa kwa mapulaneti kumayamba kale kwambiri mapulaneti asanakhalepo—ngakhale nyenyezi zisanakhalepo. Malo ozungulira nyenyezi ali ndi mitambo ya mamolekyulu, zosonkhanitsira mpweya (makamaka hydrogen ndi helium) ndi fumbi laling'ono kwambiri. Mitambo iyi ndi yozizira kwambiri komanso yofooka, komabe imatha kukhala yayikulu kwambiri. Nthawi ina, mtambo wa mamolekyulu ukhoza kukhala wosakhazikika. Zomwe zimayambitsa kusakhazikika zimatha kukhala zosiyanasiyana: mafunde ogwedezeka ochokera ku supernova yapafupi, kugundana pakati pa mitambo, kapena kusokonezeka kwa mphamvu yokoka komwe kumachitika chifukwa cha kudutsa kwa nyenyezi ina.
Pamene gawo la mtambo limakhala lolimba mokwanira, mphamvu yokoka imayamba "kupambana" mphamvu ya kutentha yomwe ikuyesera kufalitsa zinthuzo pakati. Kugwa kwa mphamvu yokoka kumachitika: zinthu zimakokedwa pakati, ndikupanga pakati pokhuthala kwambiri. Iyi ndi gawo loyamba la kupangidwa kwa nyenyezi yodziwika bwino—nyenyezi yamtsogolo—yomwe pamapeto pake idzakhala pakati pa dongosolo la mapulaneti.
2. Mphamvu yokoka ndi kupangika kwa ma disk a protoplanetary
Kugwako sikumachitika molunjika pakati ngati kugwa kosavuta. Mitambo ya mamolekyu nthawi zambiri imakhala ndi kuzungulira pang'ono. Zinthu zikagwa, kuzungulira kumeneku kumawonjezeka chifukwa cha kusunga mphamvu ya angular (monga momwe munthu wokwera skate akukokera manja ake kuti afulumizitse kuzungulira kwawo). Zotsatira zake, zinthu zomwe zikugwa sizimagunda pakati nthawi yomweyo koma zimafalikira kuti zipange kapangidwe kosalala, kozungulira: diski ya protoplanetary.
Apa ndi pomwe mphamvu yokoka imagwira ntchito ziwiri. Choyamba, mphamvu yokoka ya protostar imagwira zinthu zomwe zili mu disk pamodzi ndikuziletsa kuti zisatulukire mumlengalenga. Chachiwiri, mphamvu yokoka pakati pa tinthu tating'onoting'ono mkati mwa disk imathandiza kuti zinthuzo ziyambe kusonkhana pamodzi. Diski ya protoplanetary ndi "fakitale" ya mapulaneti, komwe mpweya ndi fumbi zimagwirira ntchito kwa zaka mamiliyoni ambiri.
3. Kuchokera ku fumbi kupita ku mapulaneti: mphamvu yokoka ngati guluu
Poyamba pa disk, tinthu ta fumbi timagundana ndi kumamatirana chifukwa cha mphamvu zamagetsi komanso "kumamatira" pamalo ooneka ngati ma microscopic. Komabe, kuti tipite patsogolo kuchoka pa fumbi kupita ku zinthu zazikulu, mphamvu yokoka imatenga malo ake. Pamene tinthu ta fumbi tili tokwanira (kuyambira mamita mpaka makilomita), kulemera kwawo kumawapatsa mphamvu yokoka. Zinthu zimenezi zimatchedwa planesitemasimals.
Mphamvu yokoka ya Planetesimal imagwira ntchito ngati guluu wa cosmic: imawonjezera mwayi woti kugundana kukhale "kowonjezera" (kuwonjezera kulemera) m'malo mogundana kapena kuwonongeka. Kuphatikiza apo, pali zotsatira zofunika kwambiri zotchedwa gravitational focus: kukoka kwa mphamvu yokoka kumakulitsa "gawo logwira ntchito bwino la chinthu," zomwe zimapangitsa kuti chigwire zinthu zina zomwe zikudutsa pafupi.
4. Kuthamanga kwa accretion: kubadwa kwa mwana wosabadwayo wapadziko lapansi
Pambuyo pa mapangidwe a mapulaneti, njira yokulira imatha kulowa mu gawo la kukula kosasunthika. Chinthu chachikulu pang'ono chimakhala ndi mphamvu yokoka, zomwe zimapangitsa kuti chigwire zinthu zambiri ndikukula kwambiri. Kusiyana pang'ono kwa kulemera kumatha kukhala kwakukulu mwachangu. Izi zimabala mazira a mapulaneti, kapena ma protoplaneti, zinthu zazikulu ngati Mwezi kapena Mars zomwe zimapitiliza kusesa zinthu zomwe zili panjira yawo.
Komabe, kukula sikupitirira mofulumira kwambiri. Pamene ma protoplaneti akuyamba kulamulira madera awo ozungulira, kuchuluka kwa kugundana kumawonjezeka ndipo zinthu zomwe zilipo zimachepa. Gawoli limasintha kukhala kukula kwa oligarchic: ma protoplaneti akuluakulu angapo ("oligarchs") amakula pamodzi, akukhudzana mwamphamvu ndikulamulira madera awo.
5. Mphamvu yokoka imapanga kapangidwe ka kuzungulira
Mapulaneti samangokhudza kulemera kokha, komanso kuzungulira. Mphamvu yokoka ya nyenyezi imapangitsa kuti mapulaneti azizungulira, pomwe kuyanjana kwa mphamvu yokoka pakati pa ma protoplaneti ndi mapulaneti ena kumatsimikizira ngati njira zozungulirazo zili zokhazikika kapena zosokonezeka.
Pakapangidwa, ma protoplaneti nthawi zambiri amakumana ndi kukoka kwa mpweya ndi mphamvu kuchokera ku disk. Izi zingayambitse kusamuka, kusintha kwa mayendedwe awo mkati kapena kunja. Kusamuka kumachitika chifukwa cha kusinthana kwa mphamvu ya angular pakati pa dziko lapansi ndi disk ya gasi, yomwe kwenikweni ndi mphamvu yokoka. Ma system ambiri opezeka a exoplanetary amasonyeza mapulaneti akuluakulu omwe ali pafupi kwambiri ndi nyenyezi zawo (hot Jupiters), omwe akukayikiridwa kuti adapanga patsogolo kenako nkusamukira mkati.
Kupatula kusamuka, mphamvu yokoka imathanso kugwira mapulaneti mu ma resonance a orbital, omwe ndi ma pattern ozungulira nthawi, monga 2:1 kapena 3:2, pomwe mapulaneti awiri "amatseka" mphamvu yokoka ya wina ndi mnzake, ndikukhazikitsa ma round awo mu chiŵerengero china. Ma resonance awa amapezeka m'ma system angapo a mwezi wa Jupiter komanso m'ma system osiyanasiyana a exoplanetary.
6. Mphamvu yokoka ndi kusiyana pakati pa mapulaneti amiyala ndi zimphona za mpweya
N’chifukwa chiyani pali mapulaneti ang’onoang’ono, okhala ndi miyala (monga Dziko Lapansi ndi Mars) ndi magesi akuluakulu (monga Jupiter ndi Saturn)? Mphamvu yokoka imagwira ntchito, limodzi ndi kutentha ndi kufalikira kwa zinthu mu diski.
Mu diski yamkati, pafupi ndi nyenyezi, kutentha kwambiri kumapangitsa kuti zikhale zovuta kuti zinthu zosinthasintha (monga madzi, methane, ammonia) ziume. Patsala miyala yochepa ndi zitsulo kuti zipange mapulaneti. Chifukwa chake, ma protoplaneti m'derali nthawi zambiri samakhala akuluakulu mokwanira kuti akoke ndikusunga mlengalenga wokhuthala kwambiri wa mpweya.
Kupitirira malire awa kuli "mzere wa chipale chofewa," malire omwe kutentha kwake kumakhala kotsika mokwanira kuti ayezi apange. Ayezi amawonjezera kuchuluka kwa thunthu lolimba lomwe likupezeka. Pakati pa dziko lapansi pakhoza kukula mofulumira, kufika pa thunthu lofunika kwambiri pomwe mphamvu yake yokoka imatha kukoka mpweya wambiri wa haidrojeni ndi heliamu kuchokera mu diski. Ichi ndiye chinsinsi cha kubadwa kwa gasi wamkulu: mphamvu yokoka ya pakati imalola kuti gasi achuluke mwachangu mpweya wa disk usanathe.
7. Kugundana kwakukulu ndi kutha kwa kupangidwa kwa mapulaneti
Mu magawo omaliza, pamene mpweya wa disk uchepa ndipo gawo lalikulu la solid mass likhala ma protoplanets, dongosololi silinakhazikikebe "mokhazikika." Mphamvu yokoka pakati pa ma protoplanets ingayambitse kuti mayendedwe awo adutse, zomwe zimayambitsa kugundana kwakukulu. Kugundana kumeneku kumakhulupirira kuti kwapanga zinthu zambiri zofunika: mwachitsanzo, lingaliro la giant impact limafotokoza chiyambi cha Mwezi, pamene chinthu chachikulu ngati Mars (chomwe nthawi zambiri chimatchedwa Theia) chinagundana ndi Dziko Lapansi laling'ono, zinyalala zake zikupanga disk ndipo pamapeto pake zinalumikizana ndi Mwezi.
Kugundana kwakukulu kungapangitse mapulaneti kukhala ndi ma cores osiyanasiyana, kuzungulira mofulumira, kupendekeka kwakukulu kwa axial, kapena kuchotsa malo a dziko lapansi. Apanso, zonse zimadalira mphamvu yokoka: mphamvu yomwe imalamulira njira, liwiro la kugundana, ndi kuthekera kwa zinyalala kuyanjananso.
8. Mphamvu yokoka pambuyo pa kupangidwa kwa dziko lapansi: kuyeretsa ndi kukhazikika
Dziko lapansi "lopangidwa" silimangosiya kukula; limachotsanso kayendedwe kake. Likakhala ndi kulemera kokwanira, dziko lapansi lidzachotsa ma planetesimal otsala m'njira zitatu: kugundana nawo, kuwatulutsa m'dongosolo, kapena kusintha kayendedwe kake kuti asadutsenso. Ichi ndi chimodzi mwa zifukwa zomwe tanthauzo lamakono la dziko lapansi limagogomezera kuthekera "kochotsa dera lozungulira."
M'kupita kwa nthawi, kukhazikika kwa dongosolo la mapulaneti kumatsimikiziridwa ndi mphamvu yokoka. Kuyanjana pang'ono kumatha kusonkhana kwa zaka mamiliyoni kapena mabiliyoni, nthawi zina kusintha kusinthasintha kwa kayendedwe ka mpweya ndi kupendekera, kapena kuyambitsa kusakhazikika komwe kumapangitsa mapulaneti kutuluka. M'machitidwe ambiri, makamaka omwe ali ndi mapulaneti oyandikana kwambiri, kulinganiza kofewa kwa mphamvu yokoka kumatsimikizira ngati dongosololi lipulumuka kapena kugwa.
Mapeto
Mphamvu yokoka ndiyo mphamvu yaikulu yomwe imasintha zinthu zakuthambo zogawanika kukhala mapulaneti okonzedwa. Imayambitsa kugwa kwa mitambo ya mamolekyu, kupanga ma disk a protoplanetary, kulola fumbi ndi miyala kugwirizana kukhala mapulaneti, kufulumizitsa kukwerana kukhala mapulaneti a protoplaneti, kuwongolera kusamuka kwa orbital ndi resonance, ndikutsimikiza ngati pulaneti ikhoza kukhala giant gasi kapena kukhalabe miyala. Ngakhale mapulaneti atapangidwa, mphamvu yokoka imapitirizabe kusintha kusintha kwa dongosololi kudzera mu kugundana, kuyera kwa orbital, ndi kusintha kwa nthawi yayitali.
Mwa kuyankhula kwina, pulaneti iliyonse ndi yopangidwa ndi mphamvu yokoka—mphamvu yosavuta yomwe, pakapita nthawi komanso mogwirizana ndi zovuta, yapanga mitundu yosiyanasiyana ya maiko m'chilengedwe chonse.
