Tavsifi umumii jirmkhoi khurdi Sistemai oftoby

Asteroidkho (Sayyorakhoi khurd). Asteroidho (az kalimai yunony – manoyash sitoramonand) asosan ba sitoraho monandand. Madorhoyashon dar bayni madorkhoi Mirrikh va Mushtary joygir shudaand (rasmi 5.8.1). Masofai umumii onho az Oftob bo yorii formulai Titsius-Bode muayyan karda meshavad (nigared ba §5.3).

Tanho bazei onho hangomi az ruyi madorashon harakat kardan dar perigeliy ba madori sayyoraho nazdik meshavand. Masalan, Germes dar perigeliy (nazdiktarin masofa az ruyi mador nisbat ba Oftob) ba madori Zuhra nazdik meshavad. Sayyorai khurdi digar Ikar boshad, hatto madori Utoridro burida, dokhili on megardad.

YAke az sayyoraho Gidalgo az ruyi madori tulonii khud ba madori Zuhal to 5,7 vohidi astronomy nazdik meshavad.

Qarib 97% sayyorahoi khurd az Oftob dar hududi 2,2 va 3,6 vohidi astronomy mekhoband.

Avvalin shuda 1-umi yanvari soli 1801 astronomy itoliyovy Piagsi dar bayni sitoraho                     jirmi sitora monandrodar yoft kard, ki nisbati sitorahoi hamsoya harakati farkkunanda dosht. Dar natijai purra omukhta shudani harakati on malum gardid, ki vay az ruyi madori ellipsy dar atrofi Oftob kharakat mekunad. Ba on Tserera nom guzoshtand. Qutri on kalontarin buda, ba 950 km barobar ast. Dere naguzashta boz se sayyorai khurd – Pallada, Vesta va YUnona yoft shudand. Holi khozir karib 3000 sayyorakhoi khurd ba mo malumand.

Qutri khurdtarini asteroidkhoi                                                                           ba 1 km barobarast. On ba andozai jirmkhoe muvofikat mekunad, ki khangomi ba Zamin aftidanashon tanurai meteoritiro khosil kardaand.

 Mikdori ziyodi asteroidkho jirmkhoi shaklashon gunogun meboshand. Ekhtimol meravad, ki onkho dar natijai bo kham barkhurda, pora shudani jismkhoi kalon paydo shudaand. Lakhtaporakhoe, ki andozaashon az 1 km khurd ast mintakai meteorii changu guborro dar Sistemai oftoby khosil 220 kardaand. In mintaka dar natijai az on inikosshavy va parokandashavii nurhoi Oftob ba mo ravshan menamoyad. Rush- noii onro rushnoii zodiaky me- nomand. Rushnoii zodiakiro faslhoi bahoru tiramoh dar arzhoi chanubii Zamin badi gurub (furud) va pesh az tului (baromadi) Oftob mushohida kardan mumkin ast.

Vazi choygirshavii guruhi sayyorachaho taachchubovar ast. Gardishi onho dar atrofi Oftob ba masofae muvofik
Massai umumii asteroidho az hazor yak hissai massai Za- minro tashkil medihad. Dar kabati madorii asteroidho sayyorahoi hele hurd niz hastand.

To imruz ziyoda az 15-to hamin guna sayyorachaho yofta shudaand va ba onho nomhoi qahramononi changi Troyan dar YUnon (Ahilles, Patrokl, Gektor, Nestor, Odissey va gayra)-ro guzoshtaand. Az in sabab in sayyorachahoro holo dar astronomiya «Troyanho» meno- mand (rasmi 5.8.2).

Az «Troyanho» 9-to pesh az Mushtary va bokimonda az ka- foi on dar atrofi Oftob ha- rakat mekunand.

Masalan, navisandai Rim Pliniy (79 solshumorii mo) navishta bud: «…kometaho dahshatnokand, …mo medonem, ki dar jangi bayni Sezaru Pompey jy kadar hunreziho shud.., in sitorai hatarnok ast, vay bo muyhoi ravshanash dar Zamin hama jizro nobud mesozad». Tarikhshinosi Rim Svetoniy guftaast, ki hangomi paydoshavii jirmi dumdor shoh Neron ba gazab omada, hunreziho kardaast. Paydoishi kometaho guyo ba margi imperatori Rim Konstantin (s. 336), SHohi Faronsa Lyudovik (s. 837\” shohi Polsha Boleslav (s. 1024), shohi inglis Rijard I (s. 1189) va gayra sabab shuda boshad.

Bo paydoshavii kometaho odamon ba vohima aftida, dumi kometahoro tavre medidand, ki guyo dar on shamsheri otashin, hanjari shulavar, sumi asp, ajdaho, sarhoi burida va gayra namoyon boshad. Odamon dar davrai tulony kometai dumdori kalon- ro dida, ba fikru hayol meraftand, holathoi dahshatnokro tasvir karda, bo tarsu haros az bemorihoi dil va fishori balandi hun nogahon mefavtidand.

Vale odamone ham budand, ki onho ba kometa hamjun yak jirmi muqarrarii osmon nazar mekardand. Doir ba in hodisa shohi Faronsa Lyudoviki XIV soli 1680 bo maksadi fahmidani hakikati hol ba olimon murojiat karda bud.

SHumorai ziyodi kometaho dar perigeliy ba Oftob Hgle nazdik shuda, dar afeliy (durtarin masofa az Oftob) to millionho km dur meshavand. YAdroi kometaho (kismi markazy) najandon kalon buda, az sadho m to yakjand km-ro dar bar megirad. Vay az gazhoi gunoguni zudbuhori yahshuda iborat ast, ki dar sharoiti mukarrary hatman ba holati gazy tabdil meyoband.

YAdroi kometa hangomi az ruyi madorash ba Oftob nazdik shudan garm meshavad. Dar lahzahoi nazdikshavy hodisai buhorshavii moddahoi gazmonandi noustuvori yadro sar meshavad. Dar natija dar tarafi ba Oftob nigaroni yadro abrjai gazi tumanmonand – koma hosil meshavad. YAdro va koma dar yakjoyagy sari kometaro tashkil medihand (rasmi 5.8.3).

Modome, ki koma az molekulahoi gazmonandi noustuvor paydo shudaast, pas, meboist yadro avval az moddahoi alokai molekulaviashon ziyodtar va bad az bughoi ob N₂0, metan SN^ ammiak MI₃, duoksidi karbon SO, va gayraho tashkil yofta boshad. Onho hamjun moddahoi tarkiby, dar haroraty past jismi sahti yahinro hosil mekunand va ba yadroi kometa, ki az moddahoi meteory – ohan, kalsiY, magniy, marganets, kremniY, nikel, alyuminiy va gaYra tashkil yoftaand, guyo jasponida shudaand.

Ba kometa hangomi ba Oftob nazdik shudanash garmii nuri rushnoy, «shamoli oftoby», fishori seli rushnoy va kuvvai jozibai Oftob tasir merasonand. Dar avval zarrachaho dar natijai tasiri nurhoi tafson az tarafi ba Oftob nigaroni kometa kanda shuda, dar tahti tasiri kuvvai joziba ba suyi Oftob harakat mekunand, vale dar oyanda «shamoli oftoby» ba harakati zarrachaho tasir karda, onhoro ba samti muqobil mepartoyad, ki dar natijai on dumi kometa hosil meshavad. Masohati didashavandai dumi kometa hangomi nazdikshavy ba Oftob meafzoyad (rasmi 5.8.4).

Zichii changu gubori dumi kometaho dar holatest, ki hdtto sitorai dar qafoi dum joygirshuda ba jashm namoyon meshavad (rasmi 5.8.5).

Se namudi dumhoro fark kardan mumkin ast (rasmi 5.8.3). Dumi namudi (tipi) I dar hati rosti pahnshavii «shamoli oftoby» hobida, mukobili Oftob nigaronida shudaast. Fishori radiatsiyai «shamoli oftoby» dar in holat nazar ba kuvvai joziba dahho marotiba ziyod ast. Dumi namudi II rost buda, az hati pahnshavii rushnoy dar tahti kunj kame hamida shudaast. Quvvai fishori «shamoli oftoby» az kuvvai joziba andake ziyod ast. Dumi namudi III shakli hele hamidashudaro doshta, ba on «shamoli oftoby» nazar ba kuvvai joziba kamtar tasir mekunad. Namudi I az atomhoi ionshudai N2, SO, va SN, namudi II az molekulahoi neytralii moddahoe, ki dar namudi I has- tand va namudi III az jangjahoi andozaashon gunogun tashkil yoftaand.

Dumi kometaho hangomi az Oftob dur shudan hurd shuda, rafta-rafta nest meshavad (rasmi 5.8.4).

Dar davomi harakat az ruyi mador moddahoi yadrogii kome- ta, ki az hisobi buhorshaviashon dumro hosil mekunand, dar

Kome gahoe, ki dar onho davri gardish az ruyi mador dar atrofi Oftob takror meyobad, kometakhoi davry nomida meshavand. Kometai Galley bori okhir soli 1986 mushohida shudaast. Davri gardishi on ba 76 sol muvofik meoyad. Pesh az in kometai G alleyro soli 1910 niz mushohida karda budand. Harakati davrii on az ruyi mador dar rasmi 5.8.7 tasvir yoftaast.

Soli 1908 dar nazdi daryoi Podkamennaya Tunguska (Rossiya) chirmi osmony ba suyi Zamin parvozkunon omada va ba on narasida, ba tarkish duchor shudaast. Dar kutri 60 km tamomi darakhtoni changalzor ba Zamin yakson shudaand (rasmi 5.8.6). In chirmi osmoniro meteoriti Tunguska nomidand. Moddakhoi meteoritro tashkilkunanda to ba imruz oshkor nigirdidiist. Gumon ast, ki vay iz lundai yakhin iborat buda, dar natichai ba soish ii muqovimati havo duchor shudan nihoyat tafson meshavad ii dar rafti parvozash ba Zamin narasida, metarkad.gubor abady memonand. Hangomi ba Zamin barkhurdani kometa hodisahoi kharobiovar rukh medihand. Vale boyad kayd kard, ki massai on az massai Zamin millionkho marotiba khurd ast.

SHumorai ziyodi kometaho binobar sababi madorhoi ellipsii durodur kasholyoftaashon hamagi yak bor mushohida shudaand. Davri kaloni gardishi onho millionho so pro tashkil medihad.
Kometahoe, ki davri gardishashon az 3 to 200 sol barobar ast, kometahoi kutokhdavr nomida meshavand. Hurdtarin davry gardish ba kometai Enke (3 sol) muvofik meoyad.

Kometaho bo soli kashfshaviashon yo bo nomi kashfkunanda nomguzori meshavand, masalan, Biela 1851 III, kometai 1811-1, Kometai 1811 II, Holms 1892 III, SHvasman-Vahman 1927 II, Vesta 19761Uva1ayra.

Meteor va meteoritkho. Meteor gufta, hodisai parvozi kutohmuddati (3-4 soniya) kurai durahshonro dar atmosferai Zamin menomand. Boqimondai chismi meteorii ba Zamin aftodaro meteo- rit menomand. Jismi meteorI ba kabathoi zichi agmosferai Zamin bo surati dahho km/s dohil shuda, ba soish va mukovimati kaloni atmosfera duchor gardida metafsad va dar naticha gudozishu buhorshavii on ba amal meoyad. In hodisa dar balandihoi 100-120 km az sathi Zamin sar shuda, dar balandii 80 km anchom meyobad. Jarayoni shadidi havo az sathi meteorit poraho va zarrahoi hurdu kaloni gazi moddahoro ba kafo mepartoyad. Dar baze lahzaho chirmi meteorI ba atmosferai Zamin vorid shuda, hodisai ba amal meorad, ki dar natichai on sadohoi galogula, gulduros va hushtak ba gush merasad. Holati parvozi kurai otashiyai dumdorro, ki on ba parvozi meteor hos ast. bolid menomand. Bolid chun kurai durahshon dar lahzai parvoz dar kafoi hud paIi suhtai dummonandro hosil mekunad. Onho aksaran ando- zai nazarrase dorand va az in ru, bazei onho ruzona ham mushohida meshavand.

Dar rafti parvoz bazei onho energiyai hudro talaf doda, ba havo duchor meshavand va surati kaIhonii hudro gum karda, ba Zamin meaftand.

Dar natichai porashavii yadroi kometaho va hatto asteroidhoi ba falokat duchorshuda kabathoi meteorI paIdo shudaand. Solhoi ohir yak kator selhoi meteorI ba kaId girifta shudand, ki onho dar hakikat ba kometaho vobastagI dorand.

Jirmhoi meteorii in kabatho va Zamin dar atrofi Oftob davrI gardishi doimI dorand.

Az hamin sabab Zamin dar ruzhoi muaIyani sol az ruIi madori hud harakat karda, ba kabati meteorI dohil meshavad (rasmi 5.8.8).

Dar zeri tasiri kuvvai choziba, chismhoi meteorI ba suIi Zamin parvoz karda, seli meteorI yo hud boroni sitoragiro ba vuchud meorand. Tarzi porashavii onho dar rasmi 5.8.9 nishon doda shudaast.

Harakati har kadomi onho ba suIi Zamin nisbat ba yakdigarashon parallel mushohida karda meshavad. Vale dar hakikat in tavr nest. 2

Hathoe, ki ba mUK^O^tsh parvozi har yak meteor guzaronida meshavavd, yakkdigrro dar kadom yak nnkkaa mebbravd, ki onro radianti meteor menomand (rasmi 5.8.10).

Seli meteori ba nomi burje guzoshta meshavad, ki agar radi- anti on az hamon burj baromada boshad.

DaR okhiri aprel seli amal- kunandai meteory dar burji

Lira (Liridho) va dar mohi avgust dar burji Persey (Perseidho) mushohida karda meshavad.

H,ar shabonaruz karib 2000 meteoritho (vazni miyonaashon 100 kg) ba Zamin meaftand, vale az onho dar yak sol hamagy kkchandto yoft meshavandu halos.

Az meteorithoi yoftashuda kalontarinash Goba (janubu garbii Afriqo) meboshad, ki vaznash 500 tonna ast.

Meteoritho az jihati soht va tarkibi kimiyoiashon ohanin (4% az meteorithoi yoftashuda), sangin (92%) va ohaninu sangin (4%) meshavand.

Tarkibi meteorithoi ohdnin az 85% ohdn, 12% nikel va 3% kobalt, oltingugird, fosfor va digar elementho iborat ast.

Hdngomi tahkiki meteoriti Sihote-Alinsk, ki vazni porahoi jamshudaash 23 tonna bud, bori avval tillo va platina yoftand.
Tahkikotho nishon medihand,

haroboti dahshatnok dar zamoni hud shahodat medihad.

Agar sathi Moh ob medosht, on binobar harorati baland, kamii kuvvai choziba, shitobi aftishi ozod va surati az sath kandashavii hurd doshtanash ba buhorshavI duchor shuda, kaIho hushk meshud. In ast, ki Moh abru atmosfera nadorad.

SLVOLHO BAROI TAKROR————————————————-

1. CHiro asteroidho menomand? Asteroidkhoi kalonro nombar ku- ned va onkho chy tavr paydo shudaand?
2. Paydoishi changu gubori mintakai sayyorakhoi khurdro sharkh dikhed.
3. Kometakho chy guna sokht dorand?
4. Paydoishi kometakho va charayongirii tarsu kharosro nisbat ba onkho sharkh dikhed. Oyo paydoishi kometakho ba khodisakhoi tabiy va vokeakhoi tarikhy bois shuda metavonad?
5. YAdroi kometakho va sababkhoi paydoishi dumi onkhoro sharkh dikhed. Koma gufta, chiro menomand?
6. Aftishi kometa ba Zamin boisi vokeai nokhush shudanash mum- kin ast yo ne? Misol biyored.
7. Kometakhoi davry gufta, chiro meguyand? Kadom kometakhoi dav- riro medoned?
8. Bolid gufta, chiro menomand?
9. Kabatkhoi meteory va boroni meteoriro fakhmoned.