Babban wuri mai duhu

Babban Dark Spot (wanda aka fi sani da **GDS-89**, don Babban Dark Spot, 1989) yana ɗaya daga cikin jerin wuraren duhu a kan Neptune mai kama da bayyanar Jupiter's Great Red Spot . A shekara ta 1989, GDS-89 shine **Babban wuri mai duhu** na farko a kan Neptune wanda NASA ta Voyager 2 ta binciken sararin samaniya za ta lura da shi. Kamar wurin Jupiter, manyan wuraren duhu sune guguwa masu tsayayya. Koyaya, abubuwan da ke ciki ba su da girgije, kuma ba kamar tabo na Jupiter ba, wanda ya daɗe na daruruwan shekaru, rayuwarsu ta zama ta fi guntu, suna samuwa da ɓace sau ɗaya a kowace 'yan shekaru ko haka. Dangane da abubuwan lura da aka ɗauka tare da Voyager 2 kuma tun daga wannan lokacin tare da Hubble Space Telescope, Neptune ya bayyana yana ciyar da fiye da rabin lokacinsa tare da Babban Dark Spot. Ba a san komai game da asalin, motsi, da kuma bacewar wuraren duhu da aka lura a duniyar tun 1989.

## Halaye
Cibiyar binciken sararin samaniya ta NASA ta Voyager 2 ta kame Great Dark Spot a kudancin Neptune. Duhun, wurin siffa mai siffa (tare da girman farko na 13,000 ta kilomita 6,600 (8,100 mi × 4,100 mi)), ya kai girmansa da Duniya, kuma yayi kama da kamanceceniya da Jupiter's Great Red Spot. Babban bambanci daya da Jupiter's Great Red Spot shi ne cewa Babban Dark Spot na Neptune ya nuna ikon juyawa arewa zuwa kudu a tsawon lokaci, yayin da Babban Red Spot ke gudanar da shi a cikin wannan yankin latitude ta hanyar igiyoyin iska na gabas-yamma na duniya.[1]. A gefen guguwar, an auna iskoki har zuwa kilomita 2,100 a cikin sa'a guda (1,300 hph), mafi sauri da aka rubuta a cikin Tsarin Rana. Babban Dark Spot ana tsammanin rami ne a cikin tudun girgijen methane na Neptune. An lura da wurin a lokuta daban-daban tare da girma da siffofi daban-daban.

Babban Dark Spot ya haifar da manyan fararen girgije a ko a ƙasa da layin tropopause mai kama da girgije mai tsawo da aka samu a Duniya. Ba kamar girgije a Duniya ba, duk da haka, wanda ya ƙunshi lu'ulu'u na kankara na ruwa, girgije na Neptune ya ƙunshi lu-lu'u na methane mai daskarewa. Wadannan girgije masu tsawo suna tsakanin 50-100   sama da babban girgije. Duk da yake girgije na cirrus yawanci suna samuwa sannan su warwatse a cikin 'yan sa'o'i kaɗan, girgije a cikin Babban Dark Spot har yanzu suna nan bayan sa'o-i 36, ko juyawa biyu na duniyar.

Ana zaton duhu na Neptune yana faruwa a cikin troposphere a ƙananan tsawo fiye da siffofin girgije na sama. Kamar yadda suke da siffofi masu ɗorewa waɗanda zasu iya ci gaba da watanni da yawa, ana zaton su ne tsarin vortex.

## Rashin

Lokacin da za a sake daukar hoton wurin a watan Nuwamba na shekara ta 1994 ta hanyar Hubble Space Telescope, ya ɓace gaba ɗaya, ya bar masu binciken taurari suyi imani cewa an rufe shi ko kuma ya ɓace. Ci gaba da girgije na aboki yana nuna cewa wasu tsoffin wuraren duhu na iya ci gaba da kasancewa a matsayin guguwa duk da cewa ba sa ganuwa a matsayin fasalin duhu. Yankunan duhu na iya ɓacewa lokacin da suka yi ƙaura kusa da ma'auni, ko kuma ta hanyar wasu hanyoyin da ba a sani ba.

## Sauran wuraren duhu da aka lura

Bayan Babban Dark Spot, an lura da wasu wurare masu duhu da yawa. A shekara ta 1989, lokacin da Voyager 2 ta lura da Babban Dark Spot (GDS), an sami wuri mai duhu na biyu, Dark Spot 2 (DS2). Dark Spot 2 ya ɓace gaba ɗaya kafin shekara ta 1994. Da farko a cikin 1994, Hubble ya zama kawai wurin aiki don gano kasancewar da lura da wuraren duhu a kan Neptune kuma har yanzu ana amfani dashi har zuwa yau. Hubble yana iya kallon hotuna a tsawo mai launin shudi, wanda shine kawai hanyar da ake gani. A cikin 1994, an kafa wani wuri mai duhu na Arewa (NGDS-1994) a arewacin arewa kuma ya ɓace tsakanin 1998 da 2000. Guguwar ta tsawon lokacin ta nuna cewa tana da kwanciyar hankali a latitude.  A cikin shekara ta 1996, an kafa wani wuri mai duhu na Arewa (NGDS-1996) kuma an kiyaye shi har sai ya ɓace, wanda ya faru kafin 1998. Hakazalika da duhu mai duhu da ya gabata, wannan ya nuna kadan ko babu wani meridional drift.  A cikin 2015, shirin Hubble Outer Planet Atmosphere Legacy (OPAL) ya gano Kudancin Dark Spot (SDS).  Kudancin Dark Spot ya nuna raguwa zuwa pole kafin ya ɓace a cikin 2017. A cikin 2016, wani wuri kusan iri ɗaya kamar Great Dark Spot (GDS) ya fito a arewacin Neptune. Wannan sabon wuri, wanda ake kira Northern Great Dark Spot (NGDS), ya kasance a bayyane na shekaru da yawa. Ba a san ko wannan wuri har yanzu yana nan a duniyar ba, saboda abubuwan lura ta amfani da Hubble telescope suna da iyaka.

Kwanan nan, a cikin 2018, an gano sabon babban wuri mai duhu da karamin wuri mai duhu kuma an yi nazari. Wannan binciken duhu a arewacin Neptune ya kasance abin tunawa saboda shi ne wuri na farko mai duhu wanda Hubble Telescope ya iya rubutawa tun daga haihuwa. Guguwar ta fi karami idan aka kwatanta da wanda NASA ta Voyager 2 ta gano, amma an gano ta fi girma a diamita fiye da Tekun Atlantika a kusan kilomita 4,600 a fadin. A watan Agustan 2020, sabon Babban Dark Spot ba zato ba tsammani ya dakatar da motsi zuwa kudu kuma ya juya, sabanin tsinkaye cewa guguwar za ta ci gaba zuwa ma'auni, inda za ta hadu da yiwuwar mutuwarsa. An yi imanin cewa guguwar ta kasance mai ɗorewa a arewacin arewa saboda tasirin sojojin Coriolis. Koyaya, yayin da guguwar ta motsa zuwa ga ma'auni, sojojin Coriolis sun raunana, suna sa guguwar za ta ɓace.

A lokaci guda, an sami karamin "Dark Spot Jr". kusa da babbar guguwa, kafin ya ɓace daga baya. Dark Spot Jr. kamar yadda sunan ya nuna ya fi karami fiye da duhu na baya, kawai yana auna mil 3,900 a diamita. Bayyanar wannan guguwar ta sa masu binciken sararin samaniya suyi imani da cewa juyin juya halin guguwar da ta gabata na iya kasancewa da alaƙa da haihuwar ƙaramin guguwar.

Duk da yake har yanzu ana gudanar da bincike kan yadda aka samu guguwar, an kammala shi daga abubuwan lura game da Kudancin Dark Spot (SDS-2015) da Arewacin Babban Dark Spot (NGDS-2018) cewa asalin su ya riga ya wuce ta hanyar karuwar ayyukan girgije a yankin da aka ba shi shekaru 2-3 kafin ya zama bayyane. Guguwar daga 1989 zuwa 2018 ta nuna alamu daban-daban na motsi kuma galibi ana iya ganinsu ne kawai na 'yan shekaru. Bugu da ƙari, ɓacewar wuraren duhu ciki har da Southern Dark Spot ana iya danganta su da girgije na aboki da ke kaiwa tsakiyar guguwar kuma yana toshe ra'ayi na blue wavelengths waɗanda ake amfani da su don bin diddigin vortex, kafin ɓacewar su.

## Ayyukan da aka tsara
An gabatar da ra'ayoyi biyu na manufa ga NASA don ziyartar Neptune a cikin shekaru masu zuwa. An gabatar da Trident a cikin 2021 a matsayin aikin ganowa don ziyartar Neptune da wata Triton a cikin shekara, amma an zaɓi manufofi biyu zuwa Venus (DAVINCI+ + da VERITAS) akan shi. Neptune Odyssey wani manufa ne mai suna orbiter tare da irin wannan manufa kamar Trident kuma an yi niyya ne don ranar kaddamarwa ta 2033. Wadannan manufofi suna da babban mayar da hankali kan ƙarin koyo game da wata mafi girma na Neptune Triton, amma kuma suna da niyyar samun ƙarin bayani game da yanayin Neptune. An buga wani bincike game da aikin nukiliya da wutan lantarki zuwa Neptune ta Hukumar Kula da Sararin samaniya ta kasar Sin.

## Dubi kuma
 

* Dragon Storm (astronomy) 
* Guguwa ta waje
* Babban Red Spot, irin wannan guguwa a kan Jupiter
* Babban White Spot, irin wannan guguwa a kan Saturn
* Hypercane
* Oval BA
* Ƙananan Ƙarƙashin Duhu

## Manazarta
 
## Haɗin waje

* Babban Dark Spot na Neptune na 1989, *Windows zuwa sararin samaniya*
* Neptune's Great Dark Spot: Ya tafi amma Ba a manta da shi ba, Hoton Astronomy na Ranar, Mayu 8, 1996