TAGWAYEN KUMBUNA, ƘADDARORI BIYU DABAN-DABAN

A watan Agusta 2012, wasu kumbunan sararin samaniya biyu iri ɗaya sun bar Duniya tare: Kumbunan Van Allen (Van Allen Probes), A da B, waɗanda aka gina don nazarin ɗamarar radiation da ke kewaye da duniyarmu. Suna da siffa ɗaya mai kusurwa takwas, fanelin hasken rana huɗu iri ɗaya, kewaye ɗaya mai tsayi ƙwarai da ya karkata da digiri 10.2. Bayan aikinsu na kimiyya ya ƙare, an kashe Kumbo B a ranar 19 ga Yuli 2019, Kumbo A kuma a ranar 18 ga Oktoba 2019. A cewar hasashen da aka yi kafin aikin, dukansu ya kamata su ci gaba da zama a kewaye har 2034.

Ba abin da ya faru ke nan ba. Kumbo A ya sake shiga sararin iska a ranar 11 ga Maris 2026. Kumbo B har yanzu yana kewaye — ko da yake an kashe shi ’yan watanni kafin ɗayan. Ta yaya tagwaye biyu, da aka harba a kewaye ɗaya kuma aka wanke su da yanayin sararin samaniya iri ɗaya, za su ƙare da tsawon rai mai bambanci haka?

An sake gina kewayen shekaru takwas

Ayisha Ashruf da abokan aikinta a Vikram Sarabhai Space Centre da Indian Institute of Space Science and Technology, dukansu a Thiruvananthapuram, Indiya, sun sake gina hanyar kowane kumbo daga bayanan kewaye na jama’a, wuri ɗaya a kowace daƙiƙa 15. Ga kowane wuri, wani samfurin sararin iska ya kiyasta yawan iskar mara kauri a can sama — thermosphere — bisa ga ayyukan Rana da na filin maganadisu na Duniya a lokacin.

A ƙasan kewayensu masu tsayi, kusa da wurin da ya fi kusa da Duniya da ake kira perigee, kumbunan suna ratsawa ta cikin wannan iskar mara kauri. Kowace wucewa tana ɗan rage musu sauri. Wannan shi ne ja da baya na sararin iska (atmospheric drag), babban ƙarfin da ke saukar da taurarin ɗan Adam.

Ƙaramin giɓi da ke ci gaba da girma

Har zuwa 2022, kumbunan biyu sun ci gaba tare. Amma daga 2021, perigee nasu sun fara rabuwa. Abin mamaki, Kumbo B ne ya fara nutsewa ƙasa da farko — kusan kilomita 180 idan aka kwatanta da 200 na A — amma Kumbo A ya daɗe a ƙasa na tsawon lokaci: perigee nasa ya yi jinkiri kusa da ƙasan kowane zagaye.

Sama: girman kewayen Kumbo A (ja mai duhu) da B (shuɗi) da bambancinsu (ruwan hoda). Ƙasa: tsayin perigee nasu. Ɗamarori masu inuwa: matakan da giɓin ke tsalle; layin lemu: guguwar Mayu 2024. — Hoto na 1, Ashruf da sauransu (2026), arXiv:2610.05372.

Daga ƙarshen 2022, giɓin ya bayyana sarai. Perigee na Kumbo A ya sauka ƙasa da kusan kilomita 190 yayin da na B ya ci gaba da kasancewa sama. Tsakanin tsakiyar 2023 da 2025, A ya sauka zuwa kusan kilomita 160, B zuwa kusan 180. A cewar rubutun, zuwa 2025 Kumbo A ya shafe kusan ƙarin awa 39 fiye da tagwansa ƙasa da kilomita 263.

Ko a tsayi ɗaya, kumbunan biyu ba su sake haɗuwa da iska ɗaya ba: yanzu suna ratsa ƙasan sararin iska a latitude, longitude da lokutan rana daban-daban. Rana ɗaya, guguwa ɗaya, amma ba sararin iska ɗaya ba.

Zagaye mai muni na ja da baya

Iska tana ƙara kauri da sauri ƙwarai yayin da ake sauka ƙasa. Ɗan ƙarin lokaci a ƙasa yana nufin ƙarin ja da baya mai yawa. Ƙarin ja da baya yana saukar da kewaye, wanda ke kawo kumbon ƙasa ma fiye da haka, inda iska ta fi kauri. Marubutan sun bayyana wannan martani mai ƙara kansa (amplifying feedback) a matsayin zuciyar labarin: ƙaramin bambanci na farko da ke ciyar da kansa.

Guguwa a matsayin masu hanzartawa

Yanayin sararin samaniya ya tura ta hanya ɗaya:

• A Oktoba 2022, wani jerin ƙananan guguwar maganadisun ƙasa (geomagnetic storms) ya zo daidai da tsallen farko bayyananne a giɓin. A lokacin, Kumbo A ya riga ya kusa kilomita 180, B kuma sama da 200. Marubutan sun tuno cewa wata matsakaiciyar guguwa a Fabrairu 2022 ta riga ta jawo asarar taurarin ɗan Adam na Starlink 38 ta hanyar kumbura iska kusa da kilomita 200.
• Guguwa masu ƙarfi a Disamba 2023, sannan a Maris da Agusta 2024, kowacce ta zo daidai da sabon faɗaɗa giɓin.
• A lokacin guguwar “Gannon” ta Mayu 2024, kamar farfaɗowar Kumbo A ce ta yi jinkiri, ba ta B ba. Kumbunan biyu a lokacin suna wucewa a lokuta daban-daban na yamma, wanda zai iya zama da muhimmanci.
• A baya, Rana tana farkawa: fitar hasken ultraviolet ɗinta yana ƙaruwa tun 2019 tare da sabon zagayen Rana, yana ƙara kaurin sararin iska na sama kuma yana sa kowane ɗan bambanci a kewaye ya fi tsada.

Darussa ga kewaye-kewaye masu cunkoso

Babu guguwa ɗaya da ke bayyana shi: rabuwar ta samo asali ne daga ƙananan bambance-bambance a kewaye, waɗanda guguwa da saurin ƙaruwar yawan iska da zurfi ke ƙara girmansu akai-akai. Marubutan sun yarda da iyakokin kayan aikinsu — samfurin sararin iska na matsakaici da ke rage girman guguwa, bayanan kewaye da ke dusashewa yayin faɗuwar ƙarshe, da asarar makamashi da aka lissafa wadda dole aka rage ta sau goma don ta dace da wadda aka gani. Duk da haka sun kammala cewa kumbunan sararin samaniya biyu a kan kewaye kusan iri ɗaya za su iya ƙarewa da tsawon rai mai bambanci ƙwarai ƙarƙashin sararin sama ɗaya — darasi ne don hasashen lokacin da taurarin ɗan Adam da tarkacen sararin samaniya za su faɗo.