Astéroid

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Keur game arcad, tempo Asteroids (game komputer).

Astéroid, planét leutik, jeung planétoid mangrupakeun sinonim, sarta digunakeun keur nandaan golongan sagala rupa banda angkasa nu leutik nu kumalayang dina sistim tatasurya sarta ngorbit ka panonpoé. Astéroid (basa Yunani keur "siga-béntang") mangrupakeun kecap nu sering dipaké dina literatur basa Inggris keur planét leutik, mangrupakeun istilah nu dipilih ku International Astronomical Union; nu séjénna leuwih milih planétoid (basa Yunani: "siga-planét"). Dina Agustus 2006 ahir, IAU ngawanohkeun istilah banda-banda leutik dina sistim tatasurya ("small solar system bodies", SSSBs), nu ngawengku kalolobaan objék nu satuluyna diklasifikasikeun minangka planét leutik, saperti komét; aranjeunna ogé ngawanohkeun "planet katé" ("dwarf planet") keur objék siga itu nu panggedéna. Artikel Wikipedia ieu tetep nyebut planét leutik nu ngorbit dina sistim tatasurya beulah (kasarannana nepi ka orbit Yupiter), sarta anu mungkin miboga komposisi nu kalolobaanana "babatuan". Keur tipe objék nu séjén, saperti komét, objék Trans-Neptunian, jeung Centaur, tempo Small solar system body.

Dina sistim tatasurya, astéroid nu munggaran kanyahoan sarta panggedéna Ceres kiwari diklasifikasikeun minangka planét dwarf, sedengkeun kabéh sésana kiwari diklasifikasikeun minangka SSSBs. Kalolobaan astéroid kaasup kana beubeur astéroid utama, kalayan orbit éliptisna aya di antara Mars jeung Jupiter. Astéroid dipikirkeun minangka sésa protoplanetary disc, sarta dina wewengkon ieu kumpulan sésa protoplanetary nu jadi planét dilingkung kacona gravitasi nu gedé nu dipangaruhan ku Jupiter salila période diwangunna sistim tatasurya. Sababaraha astéroid miboga bulan atawa kapanggih minangka pasangan nu disebut sistim binér.

253 Mathilde, Astéroid tipe C.
253 Mathilde, Astéroid tipe C.

Daptar eusi

[édit] Astéroid dina sistim tatasurya

Ti kénca ka katuhu: 4 Vesta, 1 Ceres, Bulanna Bumi.
Ti kénca ka katuhu: 4 Vesta, 1 Ceres, Bulanna Bumi.

Ratusan rébu astéroid geus katimu dina sajeroeun sistim tatasurya sarta rarata panimuan kiwari nyaéta 5000 per bulan. Dina 27 Agustus, 2006, tina total 339.376 planét leutik nu kadaptar, 136.563 di antarana miboga orbit nu cukup dipikawanoh sahingga bisa dibéré nomer resmi nu permanén. Ti antara éta, 13.350[1] miboga ngaran resmi (trivia: kira-kira 650 di antara ngaran ieu merlukeun tanda pangwanoh). Nomer nu panghandapna tapi mangrupa planét leutik nu teu dingaranan nyaéta (3360) 1981 VA; planét leutik nu dingaranan kalayan nomer pangluhurna (salian ti planét dwarf 136199 Eris jeung 134340 Pluto) nyaéta 129342 Ependes [2].

Kiwari diperkirakeun yén astéroid nu diaméterna leuwih ti 1 km dina sistim tatasurya jumlah totalna aya antara 1.1 nepi ka 1.9 yuta[3]. Astéroid panglegana dina sistim tatasurya beulah jero nyaéta 1 Ceres, kalayan diaméter 900-1000 km. Dua astéroid beubeur sistim tatasurya beulah jero nyaéta 2 Pallas jeung 4 Vesta; duanan miboga diaméter ~500 km. Vesta mangrupakeun astéroid beubeur pangutamana nu kadang-kadnag katempo ku mata taranjang (dina sababaraha kajadian nu kacida jarangna, astéroid nu deukeut ka bumi bisa katempo tanpa bantuan téknis; tempo 99942 Apophis).

Massa sakabéh astéroid Beubeur Utama diperkirakeun kurang leuwih 3.0-3.6×1021 kg[4][5], atawa kurang leuwih 4% tina massa bulan. Tina ieu, 1 Ceres ngawengku 0.95×1021 kg, 32% tina totalna. Satuluyna nyaéta astéroid pangpadetna, 4 Vesta (9%), 2 Pallas (7%), jeung 10 Hygiea (3%), mawa gambaran ieu jadi 51%; tilu deui sanggeusna éta, 511 Davida (1.2%), 704 Interamnia (1.0%), jeung 3 Juno (0.9%), ukur nambah 3% kana massa totalna. Jumlah astéroid satuluyna nambah sacara éksponénsial sanajan massa masing-masingna turun ogé.

Tempo ogé Daptar astéroid nu kasohor dina Sistim Tatasurya urang, atawa Daptar astéroid dumasar runtuyannana.

[édit] Klasifikasi astéroid

Astéroid ilaharna digolongkeun jadi grup dumasar kana sipat orbitna sarta detil spéktrum sinar panonpoé anu dipantulkeunnana.

[édit] Kelompok orbit jeung kulawarga

Artikel utama: kulawarga astéroid

Loba astéroid geus digolongkeun kana kelompok jeung kulawarga dumasar kana karakteristik orbitna. Geus ilahar keur méré ngaran hiji kelompok astéroid sanggeus anggota munggaran tina grup éta tinemu. Kelompok rélatif miboga kakaitan nu leuwih longgar, sedengkeun kulawarga leuwih "raket" sarta mangrupakeun hasil tina rundayan astéroid indungna nu ancur jaman baheula.

Keur daptar lengkep ngeunaan kelompok jeung kulawarga astéroid nu kanyahoan, tempo planét leutik jeung kulawarga astéroid.

[édit] Klasifikasi spéktral

Gambar 433 Eros ieu nunjukkeun panempoan ti salasahiji tungtung astéroid across the gouge on its underside and toward the opposite end. Gambar nu leutikna 35 m ngalintang bisa katempo.
Gambar 433 Eros ieu nunjukkeun panempoan ti salasahiji tungtung astéroid across the gouge on its underside and toward the opposite end. Gambar nu leutikna 35 m ngalintang bisa katempo.

Dina taun 1975, sistim taksonomi astéroid dumasar kana warna, albedo, jeung wangun spéktral diwangun ku Clark R. Chapman, David Morrison, jeung Ben Zellner[6]. Sipat ieu ngarujuk kana komposisi bahan pabeungeutan astéroid. Asalna, aranjeunna ukur ngagolongkeun astéroid jadi tilu rupa:

  • Astéroid tipe C - ngandung karbon, 75% tina astéroid nu dipikawanoh
  • Astéroid tipe S - ngandung silika, 17% tina astéroid nu dipikawanoh
  • Astéroid tipe M - ngandung logam, kalolobaan astéroid sésana

Daptar ieu geus ngagedéan jadi ngawengku tipe-tipe astéroid séjénna. Jumlah tipena terus tumuwuh alatan leuwih lobana deui astéroid nu kaulik. Tempo Tipe spéktral astéroid keur leuwih detil atawa Kategori:Kelas spéktral astéroid pikeun daptarna.

Perlu dicatet yén perbandingan astéroid nu kanyahoan nu kabagi jadi mangrupa-rupa tipe spéktral henteu ngaréfléksikeun perbandingan sakabéh astéroid tipe nu kitu; sababaraha tipe leuwih gampang kanyahoan tibatan tipe lianna, nu akibatna ngabiaskeun total astéoid nu aya.

[édit] Masalah nu patali jeung klasifikasi spéktral

Satadina, rancangan spéktral dumasar kana kasimpulan-kasimpulan komposisi astéroid:[7]

  • C - ngandung karbon
  • S - ngandung silikat
  • M - Métalik

Tapi, hubungan antara kelas spéktral jeung komposisi téh henteu salawasna alus, katambah deui réa pisan ragem klasifikasi nu dipaké. Hal ieu geus nyababkeun kabingungan nu cukup serius. Kusabab astéroid dina klasifikasi spéktral nu béda téh sigana dijieun tina bahan nu béda ogé, jadina téh taya jaminan yén astéroid nu kelas taksonomina sarua dijieun tina bahan nu sarua ogé.

Kiwari mah, klasifikasi spéktral nu dumasar kana sababaraha survéy spéktroskopis résolusi garis badag dina taun 1990-an masih kénéh dijadikeun standar. Élmuwan henteu bisa nyaluyuan sistim taksonomi nu leuwih alus, alatan susahna manggihan pangukuran detil nu panceg keur sampel astéroid nu loba (contona spéktra résolusi nu leuwih alus, atawa data non-spéktral saperti kapadetan bakal kacida kapakéna).

[édit] Pamanggihan astéroid

243 Ida jeung bulanna, Dactyl, satelit astéroid munggaran nu kapanggih.
243 Ida jeung bulanna, Dactyl, satelit astéroid munggaran nu kapanggih.

[édit] Métode pamanggihan historis

Métoda manggihan astéroid geus dimekarkeun sacara drastis salila dua abad katukang.

Dina taun-taun terahir abad ka-18, Baron Franz Xaver von Zach ngorganisir 24 urang astronom pikeun maluruh "planét nu leungit" di langit nu diperkirakeun 2.8 AU ti Panonpoé dumasar aturan Titius-Bode, sabagiannana minangka balukar tina pamanggihan planét Uranus, ku Sir William Herschel taun 1781, dina jarak nu "diperkirakeun" ku hukum kasebut. Tugas ieu merlukeun disiapkeunnana peta langit nu digambar ku leungeun keur sakabéh béntang dina pita zodiac nu disatujuan sanggeus nepikeun ka wates kapusing. Dina peuting nu patuturut, langit digambar deui sarta objék-objék nu diharepkeun pindah ditandaan ku titik. Gerakan planét leungit nu diharepkeun harita mah 30 detik arc per jam, kakara bisa katempo ku panalungtik.

Ironisna, astéroid munggaran, 1 Ceres, henteu katimu ku anggota grup, tapi sacara henteu ngahaja dina taun 1801 ku Giuseppe Piazzi diréktur observatorium Palermo, di Sicilia. Anjeunna manggihan hiji objék nu siga béntang dina Taurus sarta anjeunna nuturkeun parobahan tempat objék ieu salila sababaraha peuting. Babaturannana, Carl Friedrich Gauss, migunakeun observasi ieu keur nangtukeun jarak pasti ti objék nu teu kanyahoan ieu nepi ka Bumi. Itungan Gauss nempatkeun objék ieu antara planét Mars jeung Yupiter. Piazzi ngaranan Ceres, déwa tatanén Romawi.

Tilu astéroid séjénna (2 Pallas, 3 Juno, 4 Vesta) kapanggih ngan sakeudeung, sababaraha taun sanggeusna, numana Vesta kapanggih taun 1807. Sanggeus dalapan taun deui maluruh tanpa hasil, kalolobaan astronom nganggep yén geus taya deui astéroid liann. Ku kituna, pamaluruhan satuuyna dibatalkeun.

Sanajan kitu, Karl Ludwig Hencke mah tetep maluruh astéroid séjénna, nu dimimitian dina taun 1830. Lima belas taun sanggeusna, anjeunna manggihan 5 Astraea, astéroid anyar munggaran salil 38 taun. Anjeunna ogé manggih 6 Hebe kurang tina dua taun satuluyna. Sanggeus ieu, astronom séjén milu dina panalungtikan ieu sahingga satuluyna mah saeutikna hiji astéroid anyar kapanggih sanggeus waktu harita (kajaba wanci perang taun 1945). Nu seneng moro astéroid nu kasohor dina jaman kiwari nyaéta J. R. Hind, Annibale de Gasparis, Robert Luther, H. M. S. Goldschmidt, Jean Chacornac, James Ferguson, Norman Robert Pogson, E. W. Tempel, J. C. Watson, C. H. F. Peters, A. Borrelly, J. Palisa, Paul Henry and Prosper Henry jeung Auguste Charlois.

Dina taun 1891, Max Wolf ngarintis dipigunakeunnana astrofotografi keur ngadetéksi asteroid, numana katémbong minangka corétan pondok dina pelat fotografis pencahayaan panjang (long-exposure). Hal ieu sacara drastis nambah rarata detéksi lamun dibandingkeun jeung métode visual saméméhna: Wolf sorangan manggih 248 asteroid, nu dimimitian ku 323 Brucia, padahal ukur saeutik leuwih ti 300 nu kapanggih nepi ka wanci digunakeunnana métodena Wolf. Deui, saabad sanggeusna, ukur sababaraha ratus asteroid nu kaidéntifikasi, dinomeran jeung dingaranan. Harita oge sabenerna kanyahoan yen loba keneh asteroid, tapi kalolobaan astronom henteu ngawaro, nyebutna oge "bentang leutik di langit".

[édit] Métode pamanggihan modéren

Nepi ka 1998, astéroid pinanggih dina prosés opat lengkah. Kahiji, hiji wewengkon langit difoto ku teleskop widang lega. Pasangan-pasangan foto dicokot, ilaharna béda sajam. Kumpulan pasangan-pasangan bisa dicokot ngaruntuy sababaraha poé. Kadua, duanana film dina wewengkon nu sarua ditempo make stéréoskop. Sababaraha banda dina orbit sabudeureun Sarangenge bakal pindah saeutik-saeutik antara pasangan film. Dina stereoskop, gambar banda bakal katempo ngambang saeutik dina saluhureun latar tukang béntang-béntang. Katilu, sakali waé hiji banda nu pindah téh kanyahoan, lokasina bisa diukur sacara présisi migunakeun mikroskop nu didigitalkeun. Lokasina bakal diukur rélatif kana lokasi béntang nu geus dipikanyaho[8].

Katilu léngkah tacan mangrupakeun pamanggihan astéroid: panalungtik ukur nimu kaahéngan, nu ukur meunang panangtuan samentara, nyieun taun pamanggihan, surat nu nunjukkeun minggu pamanggihan, sarta ahirna surat jeung nomer nu nunjukkeun nomer runtuy pamanggihan (conto: 1998 FJ74).

Léngkah pamungkas dina pamanggihan nyaéta ngirim lokasi jeung wanci observasi ka Brian Marsden di Puseur Planét Leutik. Dr. Marsden mibanda program komputer nu ngitung yén hiji kaahéngan sarua patalina jeung kaahéngan saméméhna jadi hiji orbit nu sarua. Panalungtik munggaran kalayan orbit nu geus diitung nu dianggep jadi pamanggihna, sarta manéhna meunang kahormatan pikeun ngaranan astéroid nu kapanggih tea (poko keur idin ti International Astronomical Union) sanggeus dinomeran.

[édit] Téhnologi panganyarna: ngadetéksi astéroid nu ngabahyakeun

2004 FH nyaéta titik puseur nu diturutan sacara ruruntuyan; objék nu reup bray dina klip nyaéta satelit.
2004 FH nyaéta titik puseur nu diturutan sacara ruruntuyan; objék nu reup bray dina klip nyaéta satelit.

Aya kahayang nu beuki gedé pikeun ngidéntifikasi astéroid nu orbitna meuntasan orbit Bumi, sarta bisa, tinggal nunggu wanci nu mustari, bisa tabrakan jeung Bumi (tempo astéroid nu meuntasan Bumi). Tilu grup astéroid nu deukeuteun Bumi pangpentingna nyaéta Apollo, Amor, jeung Aten. Rupa-rupa siasat pikeun méngkolkeun astéroid geus diusuulkeun.

Astéroid deukeuteun Bumi 433 Eros geus kapanggih ti saprak 1898, sarta dina 1930-an kungsi diributkeun deui ku ayana objék nu sarua. Runtuyan pamanggihannana, nyaéta: 1221 Amor, 1862 Apollo, 2101 Adonis, tur ahirna 69230 Hermes, nu jauhna ampir 0.005 AU ka Earth dina taun 1937. Ti harita astronom mimiti sadar ngeunaan tubrukan astéroid jeung Bumi.

Dua kajadian dina dasawarsa-dasawarsa terahir nambah tingkat alarm: beuki ditarimana téori Walter Alvarez ngeunaan punahna dinosaurus boa-boa alatan kajadian tubrukan, katambah ku observasi Komet Shoemaker-Levy 9 taun 1994 nu nabrak Jupiter. Militér AS ogé nyebutkeun informasi yén satelit militérna, nu diwangun keur ngadetéksi ngabeledugna nuklir, geus ngadetéksi ratusan tubrukan di saluhureun atmosfir ku objék ti pangliwatan hiji nepi ka sapuluh méter.

Sakabéh pertimbangan-pertimbangan ieu geus ngarojong digunakuennana sistim otomatis nu kacida éfisiénna nu ngandung kaméra Charge-Coupled Device (CCD) jeung komputer nu langsung dihubungkeun jeung teleskop. Ti 1998, kalolobaan astéroid geus kapanggih migunakeun sistim otomatis siga kieu. Daptar tim nu migunakeun sistim otomatis siga kieu nyaéta:[9]

  • Tim Lincoln Near-Earth Asteroid Research (LINEAR)
  • Tim Near-Earth Asteroid Tracking (NEAT)
  • Spacewatch
  • Tim Lowell Observatory Near-Earth-Object Search (LONEOS)
  • Tim Catalina Sky Survey (CSS)
  • Tim Campo Imperatore Near-Earth Objects Survey (CINEOS)
  • Tim Japanese Spaceguard Association
  • Tim Asiago-DLR Asteroid Survey (ADAS)

Sistim LINEAR nyorangan geus manggihan 67,820 astéroid nepi ka 13 Juni, 2006 [10]. Di antara sakabéh sistim otomatis, 4076 astéroid nu deukeuteun Bumi geus kapanggih [11] kaasup 600 leuwih nu diaméterna leuwih ti 1 km.

[édit] Ngaranan astéroid

[édit] Sawangan: format pangaranan

Astéroid nu kapanggih kiwari-kiwari ieu dingaranan samentara kalayan ngandung taun pamanggihan jeung kode alfanumeris (kawas 2002 AT4). Lamun hiji orbit geus dikonfirmasi, karék dibéré nomer, sarta saterusna dingaranan (contona 433 Eros). Konvénsi pangaranan resmi maké tanda kurung keur nomerna (contona (433) Eros), tapi miceun tanda kurung ogé mangrupakeun hal nu ilahar. Sacara teu resmi, ilahar ogé miceun nomer nu marengannana, atawa miceun nomer sanggeus disebutkeun sakali nalika ngaran ieu dibalikan sababaraha kali dina téks.

Astéroid nu geus dinomeran tapi tacan dingaranan bakal tetep maké panangtuan samentarana, contona. (29075) 1950 DA. Kusabab téhnik pamanggihan modéren kaida lobana manggihan astéroid anyar, beuki loba waé astéroid nu teu dingaranan. Astéroid munggaran tanpa ngaran nyaéta (3360) 1981 VA. Dina sababaraha kajadian, panetepan samentara hiji astéroid bisa dipaké minangka ngaranna sorangan: (15760) 1992 QB₁ mikeun ngaranna keur kelompok astéroid nu disebut cubewano.

Artikel ieu keur dikeureuyeuh, ditarjamahkeun tina basa Inggris.
Bantosanna diantos kanggo narjamahkeun.

[édit] Nganomeran astéroid

Asteroids are awarded with an official number once their orbits are confirmed. With the increasing rapidity of asteroid discovery, asteroids are currently being awarded six-figure numbers. The switch from five figures to six figures arrived with the publication of the Minor Planet Circular (MPC) of October 19, 2005, which saw the highest numbered asteroid jump from 99947 to 118161. This change caused a small "Y2k"-like crisis for various automated data services, since only five digits were allowed in most data formats for the asteroid number. Most services have now widened the asteroid number field. For those which did not, the problem has been addressed in some cases by having the leftmost digit (the ten-thousands place) use the alphabet as a digit extension. A=10, B=11,…, Z=35, a=36,…, z=61. A high number such as 120437 is thus cross-referenced as C0437 on some lists.

[édit] Sumber keur ngaran

Artikel utama: Harti ngaran astéroid

The first few asteroids were named after figures from Graeco-Roman mythology, but as such names started to run out, others were used —famous people, literary characters, the names of the discoverer's wives, children, and even television characters.

The first asteroid to be given a non-mythological name was 20 Massalia, named after the city of Marseilles. For some time only female (or feminized) names were used; Alexander von Humboldt was the first man to have an asteroid named after him, but his name was feminized to 54 Alexandra. This unspoken tradition lasted until 334 Chicago was named; even then, oddly feminised names show up in the list for years afterward.

As the number of asteroids began to run into the hundreds, and eventually the thousands, discoverers began to give them increasingly frivolous names. The first hints of this were 482 Petrina and 483 Seppina, named after the discoverer's pet dogs. However, there was little controversy about this until 1971, upon the naming of 2309 Mr. Spock (which was not even named after the Star Trek character, but after the discoverer's cat who supposedly bore a resemblance to him). Although the IAU subsequently banned pet names as sources, eccentric asteroid names are still being proposed and accepted, such as 6042 Cheshirecat, 9007 James Bond, or 26858 Misterrogers.

[édit] Aturan pangaranan husus

Kangaranan astéroid henteu malulu bébas keur sakabéhna: aya sababaraha rupa astéroid nu aturan-aturannana geus dikembangkeun ngeunaan sumber ngaranna. Contona Centaur (astéroid nu ngorbit antara Saturnus jeung Néptunus) dingaranan dumasar centaur mitologis, Trojan dumasar kana pahlawan ti Perang Trojan, sarta objék trans-Néptunian dumasar sumanget di dunya.

Another well-established rule is that comets are named after their discoverer(s), whereas asteroids are not. One way to "circumvent" this rule has been for astronomers to exchange the courtesy of naming their discoveries after each other. A particular exception to this rule is 96747 Crespodasilva, which was named after its discoverer, Lucy d'Escoffier Crespo da Silva, because she sadly died shortly after the discovery, at age 22 [12] [13].

[édit] Lambang astéroid

The first few asteroids discovered were assigned symbols like the ones traditionally used to designate Earth, the Moon, the Sun and planets. The symbols quickly became ungainly, hard to draw and recognise. By the end of 1851 there were 15 known asteroids, each (except one) with its own symbol. The first four's main variants are shown here:

1 Ceres Old planetary symbol of Ceres Variant symbol of Ceres Sickle variant symbol of Ceres Other sickle variant symbol of Ceres
2 Pallas Old symbol of Pallas Variant symbol of Pallas
3 Juno Old symbol of Juno Other symbol of Juno
4 Vesta Old symbol of Vesta Modern astrological symbol of Vesta

Johann Franz Encke made a major change in the Berliner Astronomisches Jahrbuch (BAJ, "Berlin Astronomical Yearbook") for 1854. He introduced encircled numbers instead of symbols, although his numbering began with Astraea, the first four asteroids continuing to be denoted by their traditional symbols. This symbolic innovation was adopted very quickly by the astronomical community. The following year (1855), Astraea's number was bumped up to 5, but Ceres through Vesta would be listed by their numbers only in the 1867 edition. A few more asteroids (28 Bellona, 35 Leukothea, and 37 Fides) would be given symbols as well as using the numbering scheme.

The circle would become a pair of parentheses, and the parentheses sometimes omitted altogether over the next few decades.[14]

[édit] Éksplorasi astéroid

Nepi ka jaman perjalanan angkasa, astéroid ukur mangrupa titik cahya leutik sanajan migunakeun teleskop panggedéna ogé sarta wangun jeung daérahna tetep ngajadikeun misteri.

Foto close-up objék nu siga astéroid munggaran dicokot dina taun 1971 nalika Mariner 9 mariksa Phobos jeung Deimos nu kagambarkeun, nyaéta dua bulan leutik bogana Mars, nu meureun nangkep astéroid. Gambar ieu muka wangun astéroid nu teu tangtu tur siga kentang, These images revealed the irregular, potato-like shapes of most asteroids, as did subsequent images from the Voyager probes of the small moons of the gas giants. The first true asteroid to be photographed in close-up was 951 Gaspra in 1991, followed in 1993 by 243 Ida and its moon Dactyl, all of which were imaged by the Galileo probe en route to Jupiter.

The first dedicated asteroid probe was NEAR Shoemaker, which photographed 253 Mathilde in 1997, before entering into orbit around 433 Eros, finally landing on its surface in 2001.

Other asteroids briefly visited by spacecraft en route to other destinations include 9969 Braille (by Deep Space 1 in 1999), and 5535 Annefrank (by Stardust in 2002).

In September 2005, the Japanese Hayabusa probe started studying 25143 Itokawa in detail and will return samples of its surface to earth. Following that, the next asteroid encounters will involve the European Rosetta probe (launched in 2004), which will study 2867 Šteins and 21 Lutetia in 2008 and 2010.

NASA is planning to launch the Dawn Mission in 2007, which will orbit 1 Ceres and 4 Vesta in 2011-2015, with its mission possibly then extended to 2 Pallas.

It has been suggested that asteroids might be used in the future as a source of materials which may be rare or exhausted on earth (asteroid mining).

[édit] Astéroid dina fiksi

Artikel utama: Astéroid dina fiksi

A common depiction of asteroids (and less often, of Comets) in fiction is as a threat, whose impact on Earth could result with incalculable damage and loss of life[15][16]. This has a basis in scientific hypotheses regarding such impacts in the distant past as responsible for the extinction of the Dinosaurs and other past catastrophes —though, as they seem to occur within tens of millions of years of each other, there is no special reason (other than creating a dramatic story line) to expect a new such impact at any close millennium.

Another way in which asteroids could be considered a source of danger is by depicting them as a hazard to navigation, especially threatening to ships travelling from Earth to the outer parts of the Solar System and thus needing to pass the Asteroid Belt (or make a time- and fuel-consuming detour around it). Asteroids in this context provide to space travel stories a space equivalent of reefs and underwater rocks in the older genre of sea-faring adventures stories[17]. And like reefs and rocks in the ocean, asteroids as navigation hazards can also be used by bold outlaws to avoid pursuit. Representations of the Asteroid Belt in film tend to make it unrealistically cluttered with dangerous rocks. In reality asteroids, even in the main belt, are spaced extremely far apart.

Before colonization of the asteroids became an attractive possibility, a main interest in them was theories as to their origin - specifically, the theory that the asteroids are remnants of an exploded planet. This naturally leads to SF plotlines dealing with the possibility that the planet had been inhabited, and if so - that the inhabitants caused its destruction themselves, by war or gross environmental mismanagement. A further extension is from the past of the existing asteroids to the possible future destruction of Earth or other planets and their rendering into new asteroids.[18][19]

When the theme of interplanetary colonization first entered SF, the Asteroid Belt was quite low on the list of desirable real estate, far behind such planets as Mars and Venus (often conceived as a kind of paradise planet, until probes in the 1960s revealed the appalling temperatures and conditions under its clouds). Thus, in many stories and books the Asteroid Belt, if not a positive hazard, is still a rarely-visited backwater in a colonized Solar System.[20]

The prospects of colonizing the Solar System planets became more dim with increasing discoveries about conditions on them. Conversely, the potential value of the asteroids increased, as a vast accumulation of mineral wealth, accessible in conditions of minimal gravity, and supplementing Earth's dwindling resources. Stories of asteroid mining became more and more numerous since the late 1940s, with the next logical step being depictions of a society on terraformed asteroids —in some cases dug under the surface, in others having dome colonies and in still others provided with an atmosphere which is kept in place by an artificial gravity. An image developed and was carried from writer to writer, of "Belters" or "Rock Rats" as rugged and independent-minded individuals, resentful of all Authority (in some books and stories of the military and political power of Earth-bound nation states, in others of the corporate power of huge companies)[21]. As such, this sub-genre proved naturally attractive to writers with Libertarian tendencies[22]. Moreover, depictions of the Asteroid Belt as The New Frontier clearly draw (sometimes explicitly) on the considerable literature of the Nineteenth-Century Frontier and the Wild West.

[édit] Tempo ogé

  • Beubeur astéroid
  • Kategori:Kelompok jeung kulawarga astéroid
  • Kategori:Astéroid
  • Daptar astéroid
  • Daptar astéroid nu dingaranan jalma penting
  • Daptar astéroid nu dingaranan tempat
  • Daptar astéroid penting
  • Harti ngaran astéroid
  • Planét leutik
  • Puseur planét leutik
  • Objék deukeuteun bumi
  • Kajadian tabrakan
  • Pangecapan ngaran astéroid

[édit] Référénsi

  1. Minor Planet Names. Dicutat 2006-09-14.
  2. Discovery Circumstances: Numbered Minor Planets (125001)-(130000). Dicutat 2006-07-12.
  3. New study reveals twice as many asteroids as previously believed. Dicutat 2006-03-28.
  4. Krasinsky, G. A.; Pitjeva, E. V.; Vasilyev, M. V.; Yagudina, E. I. (2002). "Hidden Mass in the Asteroid Belt". Icarus 158: 98-105.
  5. Pitjeva, E. V. (2005). "High-Precision Ephemerides of Planets - EPM and Determination of Some Astronomical Constants". Solar System Research 39: 176.
  6. Chapman, C. R., Morrison, D., & Zellner, B. (1975). "Surface properties of asteroids: A synthesis of polarimetry, radiometry, and spectrophotometry". Icarus 25: 104-130.
  7. McSween Jr., Harry Y.. Meteorites and Their Parent Planets. ISBN 0-521-58751-4.
  8. Carolyn Shoemaker. Dicutat 2003-06-23.
  9. Near Earth Object Program. Dicutat 2004-06-23.
  10. Minor Planet Discover Sites. Dicutat 2006-07-12.
  11. Unusual Minor Planets. Dicutat 2006-07-14.
  12. Citation from MPC 55988. Dicutat 2006-06-05.
  13. MIT News Office: Lucy Crespo da Silva, 22, a senior, dies in fall. Dicutat 2006-06-05.
  14. When Did the Asteroids Become Minor Planets. James L. Hilton. Dicutat 2006-03-26.
  15. Clarke, Arthur C. (1993). The Hammer of God.
  16. Niven, Larry (1977). Lucifer's Hammer.
  17. Asimov, Isaac (1953). Lucky Starr and the Pirates of the Asteroids.
  18. Hogan, James P. (1977). Inherit the Stars.
  19. Heinlein, Robert (1948). Space Cadet.
  20. Isaac Asimov (March 1939). "Marooned off Vesta". Amazing Stories.
  21. Williamson, Jack (1950). Seetee Ship.
  22. Smith, L. Neil (1993). Pallas.

[édit] Tumbu kaluar

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(navigator astéroid) | Astéroid munggaran | ...
 a·s·é 
Small Solar System bodies
Vulcanoid | Astéroid deukeuteun bumi | Beubeur utama | Jupiter Trojans | Centaur | Damocloid | Komét | Trans-Neptunian (Beubeur Kuiper · Scattered disc · Awan Oort)
Keur objék jeung wewengkon séjén, tempo: golongan jeung kulawarga astéroid, astéroid binér, bulan astéroid jeung sistim tatasurya
Keur daptar lengkep, tempo: Daptar astéroid. Tempo ogé Pangucapan ngaran astéroid jeung Harti ngaran astéroid.
Tata Surya
Panonpoé - Mérkurius - Vénus - Marcapada (Bulan) - Mars - Beubeur astéroid - Jupiter
Saturnus - Uranus - Néptunus - Pluto - Beubeur Kuiper - Scattered disc - Awan Oort
Baca ogé objék astronomi jeung daptar objék tata surya, disusun dumasar radius atawa massana.