Sayari : Tofauti kati ya masahihisho
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Mstari 7:
==Ufafanuzi wa sayari==
[[Wataalamu]] wa [[Umoja wa kimataifa wa astronomia]] (IAU) walikubaliana mwaka [[2006]] kuhusu ufafanuzi wa sayari. Gimba la angani linahesabiwa kuwa sayari kama linatimiza masharti matatu:<ref>[http://www.iau.org/news/pressreleases/detail/iau0603 Azimio 5A ya IAU ya 2006] "The IAU members gathered at the 2006 General Assembly agreed that a "planet" is defined as a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit." Tangazo kwenye Tovuti ya IAU, IAU 2006 General Assembly: Result of the IAU Resolution votes, iliangaliwa Mei 2016 </ref>
*(a) kama linazunguka jua kwenye [[obiti]] yake
*(b) kama [[masi]] na [[graviti]] yake zinatosha kufikia [[umbo]] linalofanana na [[tufe]] *(c) kama ni gimba tawala ya obiti yake na hivyo limeondoa magimba mengine kwenye obiti kwa graviti yake.
Ufafanuzi huo uliamuliwa kwa [[kura]] hata kama wanaastronomia wengine hawakukubali. Azimio hili liliondoa hadhi ya sayari kwa [[Pluto]] <ref> Pia na magimba mengine kama vile Ceres, [[2 Pallas|Pallas]], [[3 Juno|Juno]] na [[4 Vesta|Vesta]]. Hizi nne zilitazamwa kuwa sayari tangu kutambuliwa mnamo [[1801]] hadi kuitwa “asteroidi” kwenye [[miaka ya 1850]]. [http://aa.usno.navy.mil/faq/docs/minorplanets.php When did the asteroids become minor planets? ], Hilton, James L. kwenye tovuti ya U.S. Naval Observatory, iliangaliwa mwaka 2008</ref> iliyowahi kutazamwa kuwa sayari katika miaka iliyopita.
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