The scattered disc, which overlaps the Kuiper belt but extends out to near 500 AU, is thought to be the source of short-period comets. Scattered-disc objects are believed to have been perturbed into erratic orbits by the gravitational influence of Neptune's early outward migration. Most scattered disc objects (SDOs) have perihelia within the Kuiper belt but aphelia far beyond it (some more than 150AU from the Sun). SDOs' orbits can also be inclined up to 46.8° from the ecliptic plane. [177] Some astronomers consider the scattered disc to be merely another region of the Kuiper belt and describe scattered-disc objects as "scattered Kuiper belt objects". [178] Some astronomers also classify centaurs as inward-scattered Kuiper belt objects along with the outward-scattered residents of the scattered disc. [179] Eris and Gonggong Phillips, J. P. (1965). "Kepler's Echinus". Isis. 56 (2): 196–200. doi: 10.1086/349957. ISSN 0021-1753. JSTOR 227915. S2CID 145268784. Main articles: Asteroid belt and Asteroid Linear map of the inner Solar System, showing many asteroid populations The Solar System". Nine Planets. Archived from the original on 17 October 2000 . Retrieved 15 February 2007. Tours of Model Solar Systems". University of Illinois. Archived from the original on 12 April 2011 . Retrieved 10 May 2012.

cos ⁡ ψ = cos ⁡ ( β g ) cos ⁡ ( β e ) cos ⁡ ( α g − α e ) + sin ⁡ ( β g ) sin ⁡ ( β e ) {\displaystyle \cos \psi =\cos(\beta _{g})\cos(\beta _{e})\cos(\alpha _{g}-\alpha _{e})+\sin(\beta _{g})\sin(\beta _{e})} Elkins-Tanton, L. T.; Smrekar, S. E.; Hess, P. C.; Parmentier, E. M. (March 2007). "Volcanism and volatile recycling on a one-plate planet: Applications to Venus". Journal of Geophysical Research. 112 (E4). Bibcode: 2007JGRE..112.4S06E. doi: 10.1029/2006JE002793. E04S06. Cassini Passes Through Asteroid Belt". NASA. 14 April 2000. Archived from the original on 25 January 2021 . Retrieved 1 March 2021.

Nakano, Syuichi (2001). "OAA computing section circular". Oriental Astronomical Association. Archived from the original on 21 September 2019 . Retrieved 15 May 2007. Asteroids in the asteroid belt are divided into asteroid groups and families based on their orbital characteristics. Kirkwood gaps are sharp dips in the distribution of asteroid orbits that correspond to orbital resonances with Jupiter. [124] Asteroid moons are asteroids that orbit larger asteroids. They are not as clearly distinguished as planetary moons, sometimes being almost as large as their partners (e.g. that of 90 Antiope). The asteroid belt includes main-belt comets, which may have been the source of Earth's water. [125] Mejías, Andrea; Minniti, Dante; Alonso-García, Javier; Beamín, Juan Carlos; Saito, Roberto K.; Solano, Enrique (2022). "VVVX near-IR photometry for 99 low-mass stars in the Gaia EDR3 Catalog of Nearby Stars". Astronomy & Astrophysics. 660: A131. arXiv: 2203.00786. Bibcode: 2022A&A...660A.131M. doi: 10.1051/0004-6361/202141759. S2CID 246842719. Quaoar (43.69AU average from the Sun) is the second-largest known object in the classical Kuiper belt, after Makemake. Its orbit is significantly less eccentric and inclined than those of Makemake or Haumea. [169] It possesses a ring system and one known moon, Weywot. [172] Ekers, Ron. "IAU Planet Definition Committee". International Astronomical Union. Archived from the original on 3 June 2009 . Retrieved 13 October 2008.

With a few exceptions, the farther a planet or belt is from the Sun, the larger the distance between its orbit and the orbit of the next nearest object to the Sun. For example, Venus is approximately 0.33 AU farther out from the Sun than Mercury, whereas Saturn is 4.3 AU out from Jupiter, and Neptune lies 10.5 AU out from Uranus. Attempts have been made to determine a relationship between these orbital distances, like the Titius–Bode law [57] and Johannes Kepler's model based on the Platonic solids, [58] but ongoing discoveries have invalidated these hypotheses. [59] Arnett, Bill (2006). "Mercury". Nine Planets. Archived from the original on 5 December 2003 . Retrieved 14 September 2006. Titan Has Liquid Lakes, Scientists Report in Nature". NASA/JPL. January 3, 2007. Archived from the original on May 23, 2013 . Retrieved January 8, 2007. Bi, S. L.; Li, T. D.; Li, L. H.; Yang, W. M. (2011). "Solar Models with Revised Abundance". The Astrophysical Journal. 731 (2): L42. arXiv: 1104.1032. Bibcode: 2011ApJ...731L..42B. doi: 10.1088/2041-8205/731/2/L42. S2CID 118681206. The four outer planets, also called giant planets or Jovian planets, collectively make up 99% of the mass known to orbit the Sun. [f] Jupiter and Saturn are together more than 400 times the mass of Earth and consist overwhelmingly of the gases hydrogen and helium, hence their designation as gas giants. [129] Uranus and Neptune are far less massive—less than 20 Earth masses ( M Earth) each—and are composed primarily of ice. For these reasons, some astronomers suggest they belong in their own category, ice giants. [130] All four giant planets have rings, although only Saturn's ring system is easily observed from Earth. The term superior planet designates planets outside Earth's orbit and thus includes both the outer planets and Mars. [89]Yi, Sukyoung; Demarque, Pierre; Kim, Yong-Cheol; Lee, Young-Wook; Ree, Chang H.; Lejeune, Thibault; Barnes, Sydney (2001). "Toward Better Age Estimates for Stellar Populations: The Y 2 Isochrones for Solar Mixture". Astrophysical Journal Supplement. 136 (2): 417–437. arXiv: astro-ph/0104292. Bibcode: 2001ApJS..136..417Y. doi: 10.1086/321795. S2CID 118940644. Shaviv, Nir J. (2003). "Towards a Solution to the Early Faint Sun Paradox: A Lower Cosmic Ray Flux from a Stronger Solar Wind". Journal of Geophysical Research. 108 (A12): 1437. arXiv: astroph/0306477. Bibcode: 2003JGRA..108.1437S. doi: 10.1029/2003JA009997. S2CID 11148141.

Plutoid chosen as name for Solar System objects like Pluto". Paris: International Astronomical Union. 11 June 2008. Archived from the original on 13 June 2008 . Retrieved 11 June 2008. ESA scientist discovers a way to shortlist stars that might have planets". ESA Science and Technology. 2003. Archived from the original on 2 May 2013 . Retrieved 3 February 2007. Timeline of Solar System exploration – A comprehensive list of events in the exploration of the Solar System. Foust, Jeff (24 November 2015). "Blue Origin Flies — and Lands — New Shepard Suborbital Spacecraft". Space News . Retrieved 1 December 2015. We're going to take that same exact architecture that was demonstrated and use it on our the booster stage of our orbital vehicleMakemake (45.79AU average from the Sun), although smaller than Pluto, is the largest known object in the classical Kuiper belt (that is, a Kuiper belt object not in a confirmed resonance with Neptune). Makemake is the brightest object in the Kuiper belt after Pluto. Discovered in 2005, it was officially named in 2009. [166] Its orbit is far more inclined than Pluto's, at 29°. [167] It has one known moon. [168] IAU Planet Definition Committee". International Astronomical Union. 2006. Archived from the original on 3 June 2009 . Retrieved 1 March 2009. Wendel, JoAnna (8 January 2022). "When will the Sun die?". Space.com. Archived from the original on 9 March 2022 . Retrieved 10 March 2022. Perlerin, Vincent (26 September 2017). "Definitions of terms in meteor astronomy (IAU)". International Meteor Organization. Archived from the original on 23 January 2018 . Retrieved 10 April 2022.

Chang, Kenneth (2017-09-14). "Cassini Vanishes Into Saturn, Its Mission Celebrated and Mourned". The New York Times. ISSN 0362-4331 . Retrieved 2023-02-04. Earth's magnetic field also stops its atmosphere from being stripped away by the solar wind. [74] Venus and Mars do not have magnetic fields, and as a result the solar wind causes their atmospheres to gradually bleed away into space. [75]

A Short History of the Solar System:

Woolfson, M. (2000). "The origin and evolution of the solar system". Astronomy & Geophysics. 41 (1): 1.12–1.19. Bibcode: 2000A&G....41a..12W. doi: 10.1046/j.1468-4004.2000.00012.x. Pentreath, R. J. (2021). Radioecology: Sources and Consequences of Ionising Radiation in the Environment. Cambridge University Press. pp.94–97. ISBN 978-1009040334. Archived from the original on 20 April 2022 . Retrieved 12 April 2022. Stofan, E. R.; Elachi, C.; Lunine, Jonathan I.; Lorenz, R. D.; Stiles, B.; Mitchell, K. L.; Ostro, S.; Soderblom, L.; etal. (2007). "The lakes of Titan". Nature. 445 (1): 61–64. Bibcode: 2007Natur.445...61S. doi: 10.1038/nature05438. PMID 17203056. S2CID 4370622. The Local Bubble is a small superbubble compared to the neighboring wider Radcliffe Wave and Split linear structures (formerly Gould Belt), each of which are some thousands of light-years in length. [216] All these structures are part of the Orion Arm, which contains most of the stars in the Milky Way that are visible to the unaided eye. The density of all matter in the local neighborhood is 0.097 ±0.013 M ☉·pc −3. [217] The Solar System formed 4.568billion years ago from the gravitational collapse of a region within a large molecular cloud. [e] This initial cloud was likely several light-years across and probably birthed several stars. [10] As is typical of molecular clouds, this one consisted mostly of hydrogen, with some helium, and small amounts of heavier elements fused by previous generations of stars. As the region that would become the Solar System, known as the pre-solar nebula, [11] collapsed, conservation of angular momentum caused it to rotate faster. The center, where most of the mass collected, became increasingly hotter than the surrounding disc. [10] As the contracting nebula rotated faster, it began to flatten into a protoplanetary disc with a diameter of roughly 200AU (30billionkm; 19billionmi) [10] and a hot, dense protostar at the center. [12] [13] The planets formed by accretion from this disc, [14] in which dust and gas gravitationally attracted each other, coalescing to form ever larger bodies. Hundreds of protoplanets may have existed in the early Solar System, but they either merged or were destroyed or ejected, leaving the planets, dwarf planets, and leftover minor bodies. [15] [16] Diagram of the early Solar System's protoplanetary disk, out of which Earth and other Solar System bodies formed