Astéroid

Ti Wikipédia, énsiklopédi bébas

Keur game arcad, tempo Asteroids (game komputer).

Astéroid, planét leutik, jeung planétoid mangrupakeun sinonim, sarta digunakeun keur nandaan golongan sagala rupa banda angasa 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.

[édit] Astéroid dina sistim tatasurya

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.

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.

[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.

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

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. He discovered a new star-like object in Taurus and followed the displacement of this object during several nights. His colleague, Carl Friedrich Gauss, used these observations to determine the exact distance from this unknown object to the Earth. Gauss' calculations placed the object between the planets Mars and Jupiter. Piazzi named it after Ceres, the Roman goddess of agriculture.

Three other asteroids (2 Pallas, 3 Juno, 4 Vesta) were discovered over the next few years, with Vesta found in 1807. After eight more years of fruitless searches, most astronomers assumed that there were no more and abandoned any further searches.

However, Karl Ludwig Hencke persisted, and began searching for more asteroids in 1830. Fifteen years later, he found 5 Astraea, the first new asteroid in 38 years. He also found 6 Hebe less than two years later. After this, other astronomers joined in the search and at least one new asteroid was discovered every year after that (except the wartime year 1945). Notable asteroid hunters of this early era were 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 and Auguste Charlois.

In 1891, however, Max Wolf pioneered the use of astrophotography to detect asteroids, which appeared as short streaks on long-exposure photographic plates. This drastically increased the rate of detection compared with previous visual methods: Wolf alone discovered 248 asteroids, beginning with 323 Brucia, whereas only slightly more than 300 had been discovered up to that point. Still, a century later, only a few thousand asteroids were identified, numbered and named. It was known that there were many more, but most astronomers did not bother with them, calling them "vermin of the skies".

[édit] Métode pamanggihan modéren

Until 1998, asteroids were discovered by a four-step process. First, a region of the sky was photographed by a wide-field telescope. Pairs of photographs were taken, typically one hour apart. Multiple pairs could be taken over a series of days. Second, the two films of the same region were viewed under a stereoscope. Any body in orbit around the Sun would move slightly between the pair of films. Under the stereoscope, the image of the body would appear to float slightly above the background of stars. Third, once a moving body was identified, its location would be measured precisely using a digitizing microscope. The location would be measured relative to known star locations^[8].

These first three steps do not constitute asteroid discovery: the observer has only found an apparition, which gets a provisional designation, made up of the year of discovery, a letter representing the week of discovery, and finally a letter and a number indicating the discovery's sequential number (example: Citakan:Mp).

The final step of discovery is to send the locations and time of observations to Brian Marsden of the Minor Planet Center. Dr. Marsden has computer programs that compute whether an apparition ties together previous apparitions into a single orbit. If so, the object gets a number. The observer of the first apparition with a calculated orbit is declared the discoverer, and he gets the honour of naming the asteroid (subject to the approval of the International Astronomical Union) once it is numbered.

[édit] Téhnologi panganyarna: ngadetéksi astéroid nu ngabahyakeun

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

There is increasing interest in identifying asteroids whose orbits cross Earth's orbit, and that could, given enough time, collide with Earth (see Earth-crosser asteroids). The three most important groups of near-Earth asteroids are the Apollos, Amors, and the Atens. Various asteroid deflection strategies have been proposed.

The near-Earth asteroid 433 Eros had been discovered as long ago as 1898, and the 1930s brought a flurry of similar objects. In order of discovery, these were: 1221 Amor, 1862 Apollo, 2101 Adonis, and finally 69230 Hermes, which approached within 0.005 AU of the Earth in 1937. Astronomers began to realize the possibilities of Earth impact.

Two events in later decades increased the level of alarm: the increasing acceptance of Walter Alvarez' theory of dinosaur extinction being due to an impact event, and the 1994 observation of Comet Shoemaker-Levy 9 crashing into Jupiter. The U.S. military also declassified the information that its military satellites, built to detect nuclear explosions, had detected hundreds of upper-atmosphere impacts by objects ranging from one to 10 metres across.

All of these considerations helped spur the launch of highly efficient automated systems that consist of Charge-Coupled Device (CCD) cameras and computers directly connected to telescopes. Since 1998, a large majority of the asteroids have been discovered by such automated systems. A list of teams using such automated systems includes:^[9]

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

The LINEAR system alone has discovered 67,820 asteroids as of June 13, 2006 ^[10]. Between all of the automated systems, 4076 near-Earth asteroids have been discovered ^[11] including over 600 more than 1 km in diameter.

[édit] Ngaranan astéroid

[édit] Sawangan: format pangaranan

A newly discovered asteroid is given a provisional designation consisting of the year of discovery and an alphanumeric code (such as 2002 AT4). Once its orbit has been confirmed, it is given a number, and later may also be given a name (e.g. 433 Eros). The formal naming convention uses parentheses around the number (e.g. (433) Eros), but dropping the parentheses is quite common. Informally, it is common to drop the number altogether, or to drop it after the first mention when a name is repeated in running text.

Asteroids that have been given a number but not a name keep their provisional designation, e.g. (29075) 1950 DA. As modern discovery techniques are discovering vast numbers of new asteroids, they are increasingly being left unnamed. The first asteroid to be left unnamed was (3360) 1981 VA. On rare occasions, an asteroid's provisional designation may become used as a name in itself: the still unnamed (15760) 1992 QB₁ gave its name to a group of asteroids which became known as cubewanos.

[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

Asteroid naming is not always a free-for-all: there are some types of asteroid for which rules have developed about the sources of names. For instance Cgentaurs (asteroids orbiting between Saturn and Neptune) are all named after mythological centaurs, Trojans after heroes from the Trojan War, and trans-Neptunian objects after underworld spirits.

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

2 Pallas

3 Juno

4 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. Retrieved on 2006-09-14.
2. ↑ Discovery Circumstances: Numbered Minor Planets (125001)-(130000). Retrieved on 2006-07-12.
3. ↑ New study reveals twice as many asteroids as previously believed. Retrieved on 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. Retrieved on 2003-06-23.
9. ↑ Near Earth Object Program. Retrieved on 2004-06-23.
10. ↑ Minor Planet Discover Sites. Retrieved on 2006-07-12.
11. ↑ Unusual Minor Planets. Retrieved on 2006-07-14.
12. ↑ Citation from MPC 55988. Retrieved on 2006-06-05.
13. ↑ MIT News Office: Lucy Crespo da Silva, 22, a senior, dies in fall. Retrieved on 2006-06-05.
14. ↑ When Did the Asteroids Become Minor Planets. James L. Hilton. Retrieved on 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

Wikimedia Commons mibanda média séjénna ngeunaan

'''''Astéroid'''''

• Known Asteroid Impacts & Their Effects
• Alphabetical list of minor planet names (ASCII) (Minor Planet Center)
• Alphabetical and numerical lists of minor planet names (Unicode) (Institute of Applied Astronomy)
• Near Earth Objects Dynamic Site
• Asteroids Dynamic Site Up-to date osculating orbital elements and proper orbital elements
• Asteroid naming statistics
• Near Earth Asteroid Tracking (NEAT)
• Everything you wanted to know about comets and asteroids — Provided by New Scientist.
• Spaceguard UK
• When Did the Asteroids Become Minor Planets?
• Large amount of information on asteroid groups collected by Gérard Faure, translation Richard Miles.
• Asteroid Simulator with Moon and Earth