Nā hōkūhele dwarf i ka ʻike honua hou
He mea maʻalahi ke ʻano o ka huaʻōlelo honua dwarf—me he mea lā ʻo ia hoʻi he "honua liʻiliʻi." Akā, i ka ʻike honua hou, he ʻano ʻepekema ka honua dwarf me ka wehewehe ʻana i hānau ʻia mai ka hoʻopaʻapaʻa lōʻihi, nā holomua i ka ʻenehana nānā ʻana, a me nā loli i ke ʻano o ke kanaka e palapala ai i ka ʻōnaehana lā. Mai ka hoʻomaka ʻana o ke kenekulia 21, ua lilo nā honua dwarf i hoʻokahi o nā manaʻo hoihoi loa no ka mea aia lākou i loko o kēlā wahi "ma waena": ʻaʻole he honua nui e like me ka Honua, akā ʻaʻole hoʻi he pōhaku liʻiliʻi e like me ka hapa nui o nā asteroids. Kōkua ko lākou ola ʻana i nā kānaka ʻepekema e hoʻomaopopo i ka mōʻaukala o ka hoʻokumu ʻia ʻana o ka ʻōnaehana lā , ka neʻe ʻana o nā honua nunui, a me ke ʻano o nā kino hau ma nā ʻaoʻao o kā mākou ʻōnaehana.
Mai ka "honua" a i ka "honua dwarf": kahi hoʻololi i ka wehewehena
I nā kenekulia i hala iho nei, ua ulu pū ka wehewehe ʻana o kahi honua me ka ʻike kanaka. ʻO Pluto, no ka laʻana, ua manaʻo ʻia ʻo ia ka honua ʻeiwa mai kona ʻike ʻia ʻana i ka makahiki 1930. Eia nō naʻe, i nā makahiki 1990 a me ka hoʻomaka ʻana o nā makahiki 2000, ua hoʻomaka nā telescope ikaika a me nā ana ʻōnaehana lani e ʻike i nā mea like me Pluto he nui ma ke Kuiper Belt—ka ʻāina ma ʻō aku o Neptune i waiwai i nā kino hau. ʻO ka ʻike ʻia ʻana o nā mea e like me Quaoar, Sedna, a ʻoi aku hoʻi ʻo Eris (nona ka nui e like me a ʻoi aku paha ka nui ma mua o Pluto) ua hāpai i kahi nīnau kumu: inā he honua ʻo Pluto , pono anei e kapa ʻia nā mea like a pau he mau honua?
I ka makahiki 2006, ua hoʻokumu ka International Astronomical Union (IAU) i kahi wehewehe kūhelu o kahi honua. Wahi a kēia wehewehe ʻana, pono i kahi honua: (1) kaapuni i ka Lā, (2) loaʻa ka nui kūpono e mālama i kahi ʻano poepoe kokoke (hydrostatic equilibrium), a (3) "hoʻomaʻemaʻe i kona kaiāulu orbital" mai nā mea like. Hoʻokō ʻo Pluto i nā koi mua ʻelua, akā ʻaʻole i hoʻokō i ke koi ʻekolu no ka mea ua piha kona ʻāpana orbital i nā mea Kuiper Belt a ua hoʻopilikia ʻia e ka umekaumaha o Neptune. No laila, ua hoʻokaʻawale hou ʻia ʻo Pluto ma ke ʻano he honua dwarf.
He aha ka honua dwarf?
Wahi a ka IAU, he kino lani ka honua dwarf e:
1. Ke kaapuni nei i ka Lā.
2. He ʻano poepoe kona ma muli o kona umekaumaha ponoʻī.
3. ʻAʻole i "hoʻomaʻemaʻe" i kona wahi hoʻopuni.
4. ʻAʻole ia he satelite (ʻaʻole ia he mahina o kekahi honua ʻē aʻe).
ʻO ke kumu o ka "hoʻomaʻemaʻe ʻana i ke kaiapuni orbital" kahi ʻokoʻa koʻikoʻi. ʻO nā hōkūhele nui e like me ka Honua a i ʻole ʻo Jupiter e hoʻomalu ana i ko lākou mau orbits me ka umekaumaha: wehe lākou, hopu, a hoʻopuehu paha i nā mea ʻē aʻe, e waiho ana i ka ʻāina a puni e "maopopo." Ma ka ʻaoʻao ʻē aʻe, kaʻana like nā hōkūhele dwarf i ko lākou wahi me nā kino liʻiliʻi ʻē aʻe. ʻAʻole kēia he mea nui wale nō, akā, ʻo ke kuleana o ka dynamics orbital.
Nā hiʻohiʻona o nā hōkūhele dwarf i ʻike ʻia
A hiki i kēia lā, ua ʻike ka IAU i kekahi mau hōkūhele dwarf nui, ʻoiai ke hoʻomau nei ka papa inoa o nā moho me nā ʻike hou.
1. Pluto
ʻO Pluto ka honua dwarf kaulana loa. Aia ia ma ke Kuiper Belt a he ʻōpuni elliptical i hoʻohālikelike ʻia me ka mokulele orbital o nā honua ʻē aʻe. Loaʻa iā Pluto kahi ʻōnaehana satelite paʻakikī, me Charon, ʻoi aku ka nui ma mua o Pluto—a hiki i ka manawa i manaʻo pinepine ʻia ai he ʻōnaehana "honua pālua". Ua hōʻike ka misionari New Horizons (2015) i ka ʻili honua o Pluto, me nā pāpū naikokene hau a me nā kaha o nā kaʻina hana e like me ke ʻano o ka honua hau o ka "glaciation."
2. Nā Ceres
He honua dwarf ʻo Ceres ma ke kāʻei Asteroid ma waena o Mars lāua ʻo Jupiter. He mea kū hoʻokahi ia no ka mea ʻoi aku kona kokoke ma mua o nā hōkūhele dwarf ʻē aʻe, ʻo ka hapa nui o ia mau mea aia ma ʻō aku o Neptune. Ua loaʻa i ka misionari Dawn a NASA nā hōʻike o ka paʻakai, ka hau, a me ka hana cryovolcanic hiki (he ʻano "lua pele hau") i ka wā ma mua. Hāʻawi ʻo Ceres i nā hōʻailona koʻikoʻi ʻaʻole i hana wale ʻia ke kāʻei Asteroid me ka pōhaku maloʻo, akā aia pū kekahi i ka wai a me nā hui volatile.
3.Eris
Aia ʻo Eris ma ʻō aku o Neptune a he kumu nui ia i ka wehewehe hou ʻana o ka honua. Ua aneane like kona nui me Pluto, akā ʻoi aku ka mamao a me ka eccentric o kona kaapuni. He mahina ko Eris i kapa ʻia ʻo Dysnomia. Ma muli o kona mamao loa, ua kaupalena ʻia ka ʻike kikoʻī e pili ana i kona ʻili, akā ua manaʻo ʻia he waiwai ia i nā hau e like me ka methane a me ka naikokene.
4. Haumea
Ua kaulana ʻo Haumea no kona ʻano lōʻihi, i manaʻo ʻia ma muli o kona wili wikiwiki loa. Loaʻa iā ia nā apo lahilahi a me kekahi mau mahina. Hōʻike ʻo Haumea hiki i nā hōkūhele dwarf ke loaʻa nā ʻano kino ʻaʻole "pōʻai pololei," akā e hoʻokō mau ana i nā koi no ke kaulike hydrostatic i loko o kekahi mau palena.
5. Makemake
Aia nō hoʻi ʻo Makemake ma ke kāʻei Kuiper. He mea hoihoi kēia mea no ka mea he ʻālohilohi loa kona ʻili, e hōʻike ana i ka nui o ka hau. Loaʻa iā Makemake ma ka liʻiliʻi hoʻokahi satelite i ʻike ʻia, e kōkua ana i nā kānaka ʻepekema e koho i kona nuipa.
No ke aha he mea nui nā hōkūhele dwarf i ka ʻike hōkū o kēia au?
Ua manaʻo pinepine ʻia nā hōkūhele dwarf he "koena" mai ka hoʻokumu ʻia ʻana o ka hōkūhele—nā poloka kūkulu i lilo ʻole i mau hōkūhele piha. Akā ʻo ia ke kumu i waiwai nui ai lākou. Noho ka nui o nā hōkūhele dwarf i nā wahi "mālama" anuanu, e ʻae ana i kā lākou mau mea i hoʻokumu ʻia e mālama i ka ʻike kemika a me ke kino mai ka ʻōnaehana Solar mua.
Eia kekahi, kōkua nā haʻawina honua dwarf i ka hoʻāʻo ʻana i nā hiʻohiʻona o ka neʻe ʻana o ka honua nui. Manaʻo ke kumumanaʻo hou ua hoʻololi paha ʻo Jupiter, Saturn, Uranus, a me Neptune i nā kūlana ma ke ao holoʻokoʻa mua, e hoʻoulu ana i ka Asteroid Belt a me ka Kuiper Belt. ʻO ka hoʻolaha ʻana o nā orbits o ka honua dwarf—nā ʻano like ʻole, nā resonances, a me nā eccentricities—hiki ke hāʻawi i kahi "kapuaʻi" o kēia hanana neʻe ʻana.
Hoʻopiʻi pū nā hōkūhele dwarf i ka manaʻo he "make" mau nā kino liʻiliʻi ma ke ʻano geological. Hōʻike ʻo Pluto lāua ʻo Ceres i nā hōʻailona o ka hana, inā paha ma muli o ka hoʻomehana kūloko, nā pilina kai , a i ʻole ke kemika hau paʻakikī. I nā huaʻōlelo ʻē aʻe, he mau keʻena hoʻokolohua kūlohelohe nā hōkūhele dwarf no ke aʻo ʻana i ka geology o nā honua hau a me ka hiki ke loaʻa nā wahi e kākoʻo ana i nā mea olaola.
Nā honua dwarf a me ka hoʻomohala ʻenehana
ʻO nā holomua i ka ʻike honua o kēia au—mai nā kāmela CCD koʻikoʻi a i nā ana ʻakomi a hiki i nā telescope lewa—ke hoʻolilo nei i ka ʻike ʻana i nā hōkūhele dwarf i mea hiki ke loaʻa. ʻO nā ana e like me Pan-STARRS a me nā papahana huli mea trans-Neptunian ke kōkua nei i ka ʻike ʻana i nā moho hou ma nā wahi o waho o ka Solar System.
I ka nānā ʻana i mua, ua manaʻo ʻia ka Vera C. Rubin Observatory (me kāna Legacy Survey of Space and Time/LSST) e hoʻololi i ka ʻimi ʻana i nā mea liʻiliʻi a mamao. Ua wānana ka nui o nā mea kilo hōkū e ulu nui ana ka nui o nā hōkūhele dwarf moho, ʻoiai ma ka Kuiper Belt a me nā wahi disk i hoʻopuehu ʻia. Ua wehe pū kēia i ka hiki ke loaʻa kahi "Planet Nine" - ʻaʻole he hōkūhele dwarf, akā he hōkūhele nui i ʻike ʻole ʻia - nona ke ola ʻana i manaʻo ʻia mai nā ʻano orbital o nā mea mamao. Inā pololei kēia kumumanaʻo, ʻo kahi hōkūhele dwarf me kahi orbit loa ke kī i ka hōʻoia ʻana i ke kumu.
ʻO ka hoʻopaʻapaʻa a me ka wā e hiki mai ana o ka hoʻokaʻawale ʻana
ʻOiai ke kōkua nei ka wehewehe ʻana o ka IAU i ka hoʻomaʻamaʻa ʻana i ka hoʻokaʻawale ʻana, ʻaʻole i hoʻoholo piha ʻia ka hoʻopaʻapaʻa. Ke paio nei kekahi poʻe ʻepekema ʻo ka wehewehe ʻana o "ka hoʻomaʻemaʻe ʻana i kahi orbit" he mea hilinaʻi nui ia i ka wahi (no ka laʻana, ma ke Kuiper Belt, e ʻoi aku ka paʻakikī o ka "hoʻomaʻemaʻe ʻana i kahi orbit" ma muli o ka nui o nā mea). Aia kekahi hoʻopaʻapaʻa e pili ana i ka pono o ka wehewehe ʻana o kahi honua e pili wale i nā mea e hoʻopuni ana i ka Lā, ʻoiai ua ʻike ʻia he mau tausani o nā exoplanets e hoʻopuni ana i nā hōkū ʻē aʻe.
ʻOiai ke kūkākūkā ʻana i nā huaʻōlelo, ua lilo nā hōkūhele dwarf i māhele i hoʻokumu maikaʻi ʻia a huahua. Hoʻopili lākou i ke aʻo ʻana i nā hōkūhele, nā asteroids, nā comets, a me nā mea trans-Neptunian i loko o hoʻokahi ʻōnaehana no ka hoʻomaopopo ʻana i ka ulu ʻana o ka Solar System.
Pani
ʻOi aku nā hōkūhele dwarf i ka ʻike honua hou ma mua o nā "flops nui." He mau waihona lākou o ka mōʻaukala cosmic, nā honua kū hoʻokahi me nā apo, nā mahina, nā lewa lahilahi, a me nā hana geological hiki. Mai Ceres ma ke kāʻei Asteroid a i Pluto lāua ʻo Eris ma ka lihi o ka Solar System , hoʻonui nā hōkūhele dwarf i ke ʻano o ko mākou noʻonoʻo ʻana i ka "honua" a hōʻoia i ka ʻokoʻa loa o ka Solar System ma mua o ka mea i manaʻo ʻia i ke kenekulia 20. Me nā hanauna hou o nā telescopes a me nā misionari lewa e hiki mai ana, e hoʻomau nā hōkūhele dwarf i ke kukui—e kōkua ana i ka pane ʻana i nā nīnau nui e pili ana i ke kumu, ka dynamics, a me ke ʻano like ʻole o nā honua a puni ka Lā.
Inā makemake ʻoe, hiki iaʻu ke hoʻohui i kahi ʻāpana "papa inoa o nā hōkūhele dwarf a me ko lākou mau ʻano" ma ke ʻano papa, a i ʻole e kākau i kahi mana kaulana o ka ʻatikala no nā haumāna kula kiʻekiʻe.
