DUTSEN SARARIN SAMANIYA DA DART TA SAKE SHIMFIƊA FUSKARSA

Lokacin da kumbon DART na NASA ya bugi Dimorphos a ranar 26 ga Satumba 2022, ya sauya kewayar wannan ƙaramin dutsen sararin samaniya (asteroid) a kewayen babban abokinsa, Didymos. Na’urorin hangen nesa da ƙaramin kumbon LICIACube sun kalli wani gajimaren tarkace yana tashi. Ƙarfin motsi (momentum) da aka miƙa da siffar wannan gajimare sun nuna cewa Dimorphos tarin tarkace (rubble pile) ne: tsibin manyan duwatsu da tsakuwa mara ƙarfi, wanda da ƙyar yake haɗe.

Duk da haka, cikin dutse iri-iri na iya dacewa da waɗannan abubuwan da aka lura. Wata tawaga daga Belgium da Romania ta tambayi ina tarkacen ya tafi daga baya, da abin da hakan ke nufi ga aikin Hera na Hukumar Sararin Samaniya ta Turai (European Space Agency), wanda zai isa wajen ma’auratan a ƙarshen 2026 don kammala gwajin DART.

Ƙwayoyi miliyan takwas da ƙwallo mai nauyin kilogram 580

Masu binciken sun yi amfani da manhajar smoothed particle hydrodynamics (SPH), wadda ke raba jiki zuwa miliyoyin ƙananan ƙwayoyi masu ɗauke da nauyi kuma suke tura juna — kusan miliyan 8 a kowane gwaji.

• DART ta zama ƙwallon aluminium mai nauyin kilogram 580 da ya buge a gudun 6.14 km/s, bisa hanyar da aka sake ginawa.
• Dimorphos ya zama siffar ƙwai (ellipsoid) mai kusan mita 177 × 151 × 116: manyan duwatsu masu kusurwoyi masu faɗin mita 2.2 zuwa 18, cushe a cikin tsakuwa wadda kashi 45% nata fanko ne.
• Sigar na biyu ta ƙara babban dutse mai faɗin mita 64 a tsakiya. Nauyin jikunan biyu kilogram biliyan 3.53 da 3.79 ne.
• An haɗa janyewar Didymos, mai nisan km 1.2, da juyawar ma’auratan. Kowane gwaji ya ɗauki awa shida, kusan rabin kewayar Dimorphos a kewayen Didymos.

Kashi goma sha uku sun tashi, kashi goma sha biyu sun dawo ƙasa

• Karon ya harba kusan kashi 13% na nauyin Dimorphos, galibi a gudun ’yan santimita a kowace daƙiƙa.
• Kusan 12% na nauyin dutsen ya sake sauka a kansa. Kusan 1% Didymos ya kama shi ko ya ci gaba da kasancewa a ɗaure da ma’auratan; kusan 0.2% kawai ya tsere daga tsarin.
• Kusan 80% na abin da ya dawo ya sauka cikin minti 30.

Maimakon rami mai siffar kwano (crater), karon ya bar wata lotsa mai shimfiɗaɗɗen ƙasa. Tarkacen da ya dawo ya rufe fuskar gaba ɗaya, amma ba daidai ba: zurfin fiye da mita 8 a kewayen bakin lotsar, ’yan goma-goma na santimita kawai kusa da antipode, wurin da ke daidai kishiyar wurin karon. A cikin irin wannan raunin ƙarfin janyewa, janyewar Didymos da juyawar ma’auratan suna lanƙwasa hanyoyin tarkace mai tafiyar hawainiya; ba tare da waɗannan tasirin ba, kwaikwayo na baya sun ba da bargo daidai wa daida.

Manyan duwatsu sun huda tarkacen da ke faɗowa, sun ci gaba da kasancewa a buɗe kuma sun kare ƙasar da ke bayansu. Babban dutsen tsakiya da ƙyar ya sauya tsarin gaba ɗaya: nesa da bakin lotsar da kuma manyan duwatsu, layukan tarkacen samfuran biyu galibi ba sa bambanta a kauri da fiye da mita ɗaya.

Hagu: yankan ciki na duwatsun sararin samaniya biyu da aka kwaikwaya kafin da bayan karon (layin ƙasa: da babban dutse a tsakiya). Dama: bargon tarkace na samfurin mai daidaito daga ɓangarori huɗu (rawaya: tarkacen da ya faɗo; shuɗi: ƙasa da cm 20). — Figure 1, Raducan et al. (2026), arXiv:2610.35718.

Ƙarfin janyewa da sababbin kumburi

Kafin karon, siffar dutsen ce ta ƙayyade tsarin ƙarfin janyewa a fuskarsa. Bayan haka, babban hoton da ƙyar ya motsa, amma sauye-sauye na wuri-wuri sun bayyana, har zuwa kusan milimita 0.004 a kowace daƙiƙa murabba’i (ana auna ƙarfin janyewa a matsayin gudun da abin da aka saki ke ƙarawa a kowace daƙiƙa) — kusan 10% na ƙarfin janyewa na wurin kafin karon. Sababbin kumburin galibi sun fito ne daga manyan duwatsu masu girman mita: ana jefar da su a hankali fiye da tsakuwa, don haka sukan ci gaba da zama a kan dutsen sararin samaniyar, kuma karon yana tono waɗanda ke binne ma.

Kuma ɓoyayyen babban dutse mai faɗin mita 64 fa? Yana ƙara ƙarfin janyewa ko’ina, kawai saboda jikin ya fi nauyi, amma ba ya barin wani tsari da ke tona shi — sai a wuri ɗaya. A cikin lotsar, tonon ya kawo fuskar kusan mita 20 kusa da shi. Idan aka kwatanta da jiki mai siffa iri ɗaya da yawan matsewa (density) daidai a ko’ina (wanda ake kira Bouguer anomaly), ƙarfin janyewa a can ya fi da kusan 10% — wani 10% daban da na sama, wanda ya kwatanta dutsen kafin da bayan karon — alamar da babu ita a samfurin mai daidaito.

Ƙarfin janyewa a fuska da aka kwaikwaya kafin (sama) da awa shida bayan karon (tsakiya), da sauyin (ƙasa), ba tare da (hagu) da kuma tare da (dama) babban dutse a tsakiya ba; alamar ƙetare tana nuna wurin karon. — Figure 3, Raducan et al. (2026), arXiv:2610.35718.

Abin da na’urorin Hera za su tarar

Hera za ta auna siffa da nauyin ma’auratan. Ƙaramin CubeSat ɗinta, Juventas, zai binciki Dimorphos da radar mai ƙarancin mita (low-frequency), JuRa, kuma, bayan sauka, zai auna ƙarfin janyewa na wurin da na’urar auna ƙarfin janyewa (gravimeter) GRASS. Na’urar ɗaukar hoto HyperScout-H za ta naɗi fuskar a cikin ƙunƙuntan zangon haske tsakanin micrometre 0.65 da 0.95.

• Launuka. Haske da ke dawowa daga fuska yana binciken ’yan micrometre na sama ne kawai (kashi dubu na milimita), kuma ko mafi siraran tarin da aka hasashe sun fi haka kauri: a launukan HyperScout-H, mafi yawan Dimorphos na iya bayyana kamar an sabunta fuskarsa yanzu, yana nuna tarkacen DART maimakon fuskar da take can a da. Tsohuwar fuskar ta fi yiwuwa ta tsira kusa da antipode da kuma gefen manyan duwatsu masu ba da kariya.
• Ƙarfin janyewa. Sauye-sauyen da aka hasashe sun fi abin da GRASS za ta iya ganowa girma da kusan ninki ɗari. Manyan duwatsu na kusa da tarkace mara daidaito na iya sauya ƙarfi da kuma alƙiblar janyewar da take aunawa.
• Zurfi. Cikin can ƙasa ya fi sauƙin ji a cikin lotsar. Amma wuri ɗaya ba lallai ne ya wakilci dutsen gaba ɗaya ba, kuma ƙarfin janyewa shi kaɗai ba zai iya raba manyan duwatsu na kusa da fuska da na can zurfi ba: radar, wadda ke duba ciki, dole ta cike wannan giɓi.

Awa shida, iyakoki biyu

Waɗannan sigogi biyu ne na Dimorphos a ƙarshen iyaka, ba na ainihi ba; dukansu sun fi nauyi fiye da wani ƙiyasi na baya-bayan nan da aka samo daga motsinsa, kusan kilogram biliyan 2.7. Kaurin sun ɗauka cewa yawan matsewar tsakuwar da ta faɗo ya ragu da kashi 20% idan aka kwatanta da na da; idan ta fi zama a sako-sako, layukan sun fi kauri fiye da yadda aka ruwaito. Kuma lokacin da kwaikwayon ya tsaya a awa shida, sauran 6% na ƙarshe na tarkacen har yanzu suna kewaya ma’auratan, a kan hanyoyin da za su iya ɗaukar kwanaki zuwa makonni kafin su ƙare.