Yini Enye Esemkhathini Ngaphandle Kwamaplanethi?

IPlanethi X. Isazi sezinkanyezi uPercival Lowell sayetha leli gama iplanethi eyayingabonakali esasicabanga ukuthi izungeza ngalé kweplanethi i-Neptune. Ukuthungatha kwaso iPlanethi X kwaqala ngo-1905 esikhungweni saso sokucwaninga eFlagstaff, e-Arizona. Nakuba uLowell ashona engakayitholi iPlanethi X, ucwaningo aluqala lwaqhubeka. Ekugcineni, ngo-1930, kuso isikhungo sokucwaninga sikaLowell, uClyde Tombaugh wathola iplanethi i-Pluto. Yayikhona ngempela iPlanethi X!

Ngokushesha izazi zezinkanyezi zaqala ukuzibuza, ‘Ingabe kungenzeka kutholakale enye iPlanethi X?’ Kwalandela iminyaka engamashumi ayisithupha yokucwaninga okunzulu, kanti eminyakeni yakamuva yalolu cwaningo, kwasetshenziswa ngisho nemikhumbi-mkhathi. Nakuba kwatholakala izinkulungwane zama-asteroid, izinkanyezi, imithala nama-nebula, awekho amaplanethi amasha atholakala.

Kodwa-ke, ucwaningo lwaqhubeka. Ososayensi baqala ukusebenzisa ubuchwepheshe obusha nezibona-kude ezinamandla ukuze bathungathe izindikimba ezizungeza emkhathini ezilufifi kakhulu ezingabonakali ngeso lenyama. Ekugcineni imizamo yabo yaba nemivuzo. Ngokumangalisayo, kuye kwatholakala amaplanethi amaningi amancane angalé kweplanethi i-Pluto!

Akuphi lawo maplanethi amancane? Mangaki amanye asazotholakala? Ingabe asemajukujukwini esimiso sethu sonozungezilanga?

Izindikimba Zasemkhathini Eziqhelile

Isimiso sonozungezilanga sinamaplanethi angu-9 azungeza ilanga. Ngaphezu kwalokho, kunezinkulungwane zama-asteroid angamadwala azungeza emkhathini, amaningi atholakala emzileni ophakathi kwe-Mars ne-Jupiter. Kuye kwatholakala nezinkanyezi ezinomsila ezingaba yinkulungwane.

Yiziphi kulezi zindikimba zasemkhathini eziqhele kakhulu elangeni? Eqinisweni, yizinkanyezi ezinomsila.

Igama elithi “comet [inkanyezi enomsila]” lisuselwa egameni lesiGreki elithi ko·meʹtes, elisho ukuthi “onezinwele ezinde”—libhekisela emisileni emide engemva kwezihloko zazo ezigqamile. Izinkanyezi ezinomsila ziye zaba isisekelo sezinkolelo-ze nokwesaba okukhulu. Abantu ababuka izinkanyezi ezinomsila basazibiza ngokuthi izithunzi. Lokhu kusekelwe ezinkolelweni zasendulo zokuthi zaziyimingcwi. Kungani zesatshwa kangaka? Esinye isizathu siwukuthi ngezinye izikhathi ukuvela kwazo kuye kwahambisana nezenzakalo eziyinhlekelele.

Izinkanyezi ezinomsila zisabangela isasasa. Ngo-March 1997, eCalifornia, e-U.S.A., amalungu angu-39 ehlelo okuthiwa i-Heaven’s Gate azibulala wonke lapho inkanyezi enomsila i-Hale-Bopp isondela elangeni. Ngani? Ngoba ayekholelwa ukuthi umkhumbi-mkhathi wabantu abavela emkhathini, okuthiwa wawuhamba ngemva kwaleyo nkanyezi, wawuzofika uzowalanda.

Akubona bonke abantu abaye babheka izinkanyezi ezinomsila ngendlela engenangqondo. Ekhulwini lesine leminyaka B.C.E., u-Aristotle waveza ukuthi izinkanyezi ezinomsila zazingamafu agqamile egesi esemkhathini. Emakhulwini eminyaka ambalwa kamuva, isazi sefilosofi esingumRoma uSeneca saveza ngokuqiniseka ukuthi izinkanyezi ezinomsila ziyizindikimba ezizungeza ezulwini.

Lapho kusungulwa izibona-kude futhi kutholakala nomthetho kaNewton wamandla adonsela phansi, ukucwaninga ngezinkanyezi ezinomsila kwaphishekelwa ngokugcwele. Ngo-1705, u-Edmond Halley wayesethole ukuthi izinkanyezi ezinomsila zizungeza ilanga emizileni emide, engashintshashintshi. Ngaphezu kwalokho, waphawula ukuthi izinkanyezi ezinomsila ezavela ngonyaka ka-1531, 1607 nango-1682 zazihamba emizileni efanayo futhi zishiyana ngezikhawu eziyiminyaka engaba ngu-75. UHalley wasikisela ngokunembile ukuthi ngasinye salezi zenzakalo sasiyinkanyezi efanayo ezungezayo, kamuva eyabizwa ngokuthi i-Halley’s Comet.

Abacwaningi sebeyazi ukuthi izinkanyezi ezinomsila zinesihloko, esingaba ikhilomitha elilodwa kuya kwangu-20 ubude. Lesi sihloko singachazwa kahle ngokuthi inguzunga yeqhwa elinsundu nelingcolile, elinamanzi nothuli. Izithombe ezikhulisiwe ze-Halley’s Comet ezathathwa umkhumbi-mkhathi i-Giotto ngo-1986 zibonisa ukuthi le nkanyezi enomsila yayikhipha igesi nothuli okutshuzayo. Lokhu kwakha isihloko esigqamile senkanyezi kanye nomsila wayo okubonakala lapho umuntu esemhlabeni.

Amaqoqo Ezinkanyezi Ezinomsila

Kunamaqoqo amabili ezinkanyezi ezinomsila ezizungeza ilanga. Isigaba inkanyezi enomsila engena ngaphansi kwaso sisekelwe enkathini yayo yokuzungeza, noma ekutheni ithatha isikhathi eside kangakanani lapho ijikeleza umhlaba. Izinkanyezi zenkathi emfushane, noma zezikhathi ezithile—njenge-Halley’s Comet—zithatha iminyaka engaphansi kuka-200 ukuzungeza ilanga. Imizila ezihamba kuyo isondelene ne-ecliptic, indawo esemkhathini lapho umhlaba namanye amaplanethi ezungeza khona ilanga. Kungenzeka ukuthi kunezinkanyezi zezikhathi ezithile eziyizigidi eziyinkulungwane, eziningi zazo ezihamba emizileni engalé kweplanethi i-Neptune ne-Pluto, ebangeni elingamakhilomitha ayizigidi zezinkulungwane kusuka elangeni. Ngezinye izikhathi, ezinye zalezi zinkanyezi, njenge-Encke’s Comet, zinemizila esondele elangeni ngenxa yokuhamba kwazo eduze kwamaplanethi.

Kuthiwani ngemizila yezinkanyezi zenkathi ende? Ngokungafani nezinkanyezi zenkathi emfushane, izinkanyezi zenkathi ende zizungeza ilanga zivela nxazonke. Zihlanganisa izinkanyezi ezinomsila i-Hyakutake ne-Hale-Bopp, ebeziwumbukwane lapho zibonakala muva nje. Nokho, kulindeleke ukuba zivele ngemva kwezinkulungwane zeminyaka!

Kuneqoqo elikhulu lezinkanyezi ezinomsila zenkathi ende elizungeza emaphethelweni esimiso sonozungezilanga. Leli qoqo kuthiwa i-Oort, lethiwa ngesazi sezinkanyezi esingumDashi okuyisona esasikisela kuqala ukuthi likhona ngo-1950. Zingaki izinkanyezi ezinomsila ezikuleli qoqo? Izazi zezinkanyezi zilinganisela ukuthi zingaphezu kwezigidi eziyisigidi! Ezinye zalezi zinkanyezi zifinyelela ebangeni eliyi-light-year noma ngaphezulu ukusuka elangeni.a Uma zikude kangako, kungathatha iminyaka engaphezu kwezigidi eziyishumi ukuba zizungeze ilanga kanye kuphela!

Inqwaba Yamaplanethi Amancane

Amaplanethi amancane asanda kutholakala okukhulunywe ngawo ekuqaleni asendaweni eyodwa nezinkanyezi ezinomsila zenkathi emfushane ezingalé kweplanethi i-Pluto. Kusukela ngo-1992, izazi zezinkanyezi ziye zathola lezi zindikimba ezincane, ezinjengamaplanethi ezingaba ngu-80. Kungenzeka kunezinye ezingamashumi ezinkulungwane ezingaphezu kwamakhilomitha ayikhulu ubukhulu. La maplanethi amancane akha umzila i-Kuiper, owaqanjwa ngososayensi owasikisela ukuthi akhona eminyakeni engaba ngu-50 edlule. Izindikimba zomzila i-Kuiper ngokunokwenzeka ziyinhlanganisela yedwala neqhwa.

Ingabe ukutholakala kwala maplanethi amancane muva nje kuye kwayishintsha indlela isimiso sonozungezilanga esibhekwa ngayo? Yebo! Manje iplanethi i-Pluto, inyanga yayo i-Charon, nenyanga yeplanethi i-Neptune, i-Triton, kanye nezinye izindikimba zeqhwa ezisesimisweni sonozungezilanga kucatshangwa ukuthi zivela emzileni i-Kuiper. Ezinye izazi zezinkanyezi zicabanga ngisho nokuthi iplanethi i-Pluto akusafanele ibhekwe njengeplanethi enkulu ezimele!

Zavelaphi?

Kwenzeka kanjani ukuba izinkanyezi ezinomsila namaplanethi amancane kube kuningi kangaka emzileni i-Kuiper? Izazi zezinkanyezi zisikisela ukuthi lezi zindikimba zakhiwa yinqwaba yothuli neqhwa, okwahlangana kwaba yizindikimba ezinkulu. Nokho, lezi zindikimba zazisakazeke kakhulu ukuba zingaqhubeka zihlangana zize zibe amaplanethi amakhulu.

Izinkanyezi ezinomsila zenkathi ende nazo ziyingxenye enkulu yesimiso sonozungezilanga. Sezizonke, lezi zinkanyezi zinesisindo esiphinda esomhlaba izikhathi ezingu-40. Eziningi kucatshangwa ukuthi zavela kudala esimisweni sonozungezilanga endaweni esemkhathini yamaplanethi amakhulu anegesi.

Yini eyabangela ukuba lezi zinkanyezi zifike emizileni yamanje ekude kangaka nelanga? Kubonakala sengathi amaplanethi amakhulu, njenge-Jupiter, ayeba njengozibuthe abadonsa noma yiziphi izinkanyezi ezinomsila ezisondela kuwo.

Ukuhlola Izinkanyezi Ezinomsila

Izinkanyezi ezinomsila zakhiwa yizinto eziyisisekelo ezitholakala esimisweni sonozungezilanga. Lezi zindikimba ezithakazelisayo zingahlolwa kanjani kabanzi? Ukusondela kwezinye zazo ngezinye izikhathi esimisweni sonozungezilanga kuvula ithuba lokuba zihlolisiswe. Izinhlangano ezihlukahlukene ezihlola umkhathi zihlela ukuthumela imikhumbi-mkhathi ukuyohlola izinkanyezi ezinomsila kule minyaka embalwa ezayo.

Ubani owaziyo ukuthi yini esengatholakala esimisweni sethu sonozungezilanga? Izinto ezintsha ezisanda kutholwa nezaziwayo ngokuphathelene nezindikimba ezikude ezizungeza ilanga zigcizelela ubuqiniso bombhalo weBhayibheli olotshwe ku-Isaya 40:26: “Phakamiselani amehlo enu phezulu, nibone. Ngubani odalile lezo zinto na? Nguye okhipha ibandla lazo ngezibalo, abize zonke ngamagama.”

[Umbhalo waphansi]

[Ibhokisi ekhasini 27]

IZINKANYEZI EZINOMSILA NETHALA LEZINKANYEZI EZITSHUZAYO

Lapho ubuka inkanyezi etshuzayo inqamula emkhathini, ingabe uyazibuza ukuthi ivela enkanyezini enomsila yini? Kungenzeka kunjalo. Lapho inkanyezi enomsila isondela elangeni, isihloko sayo seqhwa siqala ukuncibilika, sikhiphe izingcezu zamadwala, noma ama-meteoroid. La madwala ayasinda kunothuli olusemsileni wenkanyezi, futhi ngenxa yalokho awasakazeki emkhathini. Kunalokho, akha ibhande lemfucumfucu elizungeza ilanga emzileni wenkanyezi avela kuyo.

Unyaka ngamunye, umhlaba ungqubuzana nedlanzana lama-meteoroid. Ithala lezinkanyezi ezitshuzayo i-Leonid elivela phakathi no-November libangelwa yimfucumfucu yenkanyezi enomsila i-Tempel-Tuttle. Leli thala livela libe umbukwane omkhulu njalo ngemva kweminyaka engu-33. Abahloli bezinkanyezi ababona ithala i-Leonid ngo-1966 babika ukuthi babona izinkanyezi ezitshuzayo ezingaphezu kuka-2 000 ngomzuzu—zaziyithala ngempela! Njengoba leli thala lakhipha izinkanyezi ezikhazimulayo ngo-1998, kumelwe ukuthi liyoba umbukwane ngempela ngo-November nonyaka.

[Umdwebo/Izithombe ekhasini 24-6]

1. Inkanyezi enomsila i-Hale-Bopp ngo-1997

2. U-Edmond Halley

3. UPercival Lowell

4. I-Halley’s Comet ngo-1985

5. I-Halley’s Comet ngo-1910

6. I-Halley’s Comet ikhipha igesi nothuli okutshuzayo

[Imithombo]

1) Tony and Daphne Hallas/Astro Photo; 2) Culver Pictures; 3) Courtesy Lowell Observatory/Dictionary of American Portraits/Dover

4) Courtesy of Anglo-Australian Observatory, photograph by David Malin; 5) National Optical Astronomy Observatories; 6) the Giotto Project, HMC principal investigator Dr. Horst Uwe Keller, the Canada-France-Hawaii telescope

[Umdwebo]

(Ukuze ubone ukuthi indaba ihlelwe kanjani, bheka encwadini)

7. Imizila yezinkanyezi ezinomsila ezihlukahlukene

I-Comet Kohoutek

I-Halley’s Comet

Ilanga

UMhlaba

I-Encke’s Comet

I-Jupiter

[Izithombe]

8. Ngaphambi kokuba ishayisane neplanethi i-Jupiter ngo-1994, inkanyezi enomsila i-Shoemaker-Levy 9 yahlukana yaba izingcezu ezingu-21

9. Iplanethi i-Pluto

10. I-Comet Kohoutek, ngo-1974

11. I-“asteroid” i-Ida nenyanga yayo i-Dactyl

[Imithombo]

8) Dr. Hal Weaver and T. Ed Smith (STScI), and NASA; 9) A. Stern (SwRI), M. Buie (Lowell Obs.), NASA, ESA; 10) NASA photo; 11) NASA/JPL/Caltech