Usoro nhazi nke Ecliptic

. Na igwe, usoro nchikota eklips bụ usoro nhazi nke mmadụ nke a na-ama ihe eme ihe maka radichite anya ngosipụta ike ìhè, orbits, na pole orientation nke ihe Sistemụ akwụkwọ .  N'ihi na ọtụtụ mbara ala (ma e wezụga Mercury ) na ọtụtụ obere Solar Sistemu ozu nwere orbits na nanị nta ike na ekliptik, iji ya dị ka isi ụgbọ elu adaba.  Sistemu si nwe ike ịbụ etiti nke ma isi ma ọ bụ ike, isi ya bụ ikepụta vernal (March) equinox, na o nwere a aka nri nri .  Enwere ike ụgbọala ya na ndekọ ma ọ bụ anɔ.
. Explanatory Supplement (1961), pp. 20, 28 The Bo equator na ecliptic ji nri na-akpụ akpụ n'ihi perturbing agha na ike, Ya mere, nghazi nke isi direction, ha intersection na Northern Hemisphere vernal equinox, na-acha ọkụ.  Ntu ụzọ dị si nke axis nke ụwa, nke mbụ, na-eme ka nhazi ahụ ji na-enye na-aga n'ihu n'ebe e nwere ike inyere okporo osisi nke eklips, na-emecha otu sekit n'ihe dị ka afọ 26,000.  .  Ekwadoro na nke a bụ obere mgbanwe nke eklips, na obere oscillation nke ụwa axis, nutation .