Order in Space: A Design Source Book

Product Information

Williams, David R. (7 September 2006). "Saturn Fact Sheet". NASA. Archived from the original on 4 August 2011 . Retrieved 31 July 2007. Main article: Scattered disc The orbital eccentricities and inclinations of the scattered disc population compared to the classical and resonant Kuiper belt objects 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})} Dyches, Preston; Chou, Felcia (7 April 2015). "The Solar System and Beyond is Awash in Water". NASA . Retrieved 8 April 2015. The astronomical unit [AU] (150,000,000km; 93,000,000mi) would be the distance from the Earth to the Sun if the planet's orbit were perfectly circular. [54] For comparison, the radius of the Sun is 0.0047AU (700,000km; 400,000mi). [55] Thus, the Sun occupies 0.00001% (10 −5%) of the volume of a sphere with a radius the size of Earth's orbit, whereas Earth's volume is roughly one millionth (10 −6) that of the Sun. Jupiter, the largest planet, is 5.2 astronomical units (780,000,000km; 480,000,000mi) from the Sun and has a radius of 71,000km (0.00047AU; 44,000mi), whereas the most distant planet, Neptune, is 30AU (4.5 ×10 9km; 2.8 ×10 9mi) from the Sun. [48] [56]

Discussion". Space Policy. 14 (1): 6. 1998-02-01. Bibcode: 1998SpPol..14....5.. doi: 10.1016/S0265-9646(97)00038-6. 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. Barucci, M. A.; Kruikshank, D. P.; Mottola, S.; Lazzarin, M. (2002). "Physical Properties of Trojan and Centaur Asteroids". Asteroids III. Tucson, Arizona: University of Arizona Press. pp.273–287. Sheppard, Scott S.; Jewitt, David; Kleyna, Jan (2004). "A Survey for Outer Satellites of Mars: Limits to Completeness" (PDF). Astronomical Journal. Archived (PDF) from the original on 3 March 2016 . Retrieved 26 December 2006. NASA launches Kepler Mission: Search for Earth-like worlds". Spacechornology.com. Archived from the original on 22 January 2011 . Retrieved 4 August 2017.The dwarf planet Pluto (with an average orbit of 39AU (5.8billionkm; 3.6billionmi) from the Sun) is the largest known object in the Kuiper belt. When discovered in 1930, it was considered to be the ninth planet; this changed in 2006 with the adoption of a formal definition of planet. Pluto has a relatively eccentric orbit inclined 17 degrees to the ecliptic plane and ranging from 29.7AU (4.44billionkm; 2.76billionmi) from the Sun at perihelion (within the orbit of Neptune) to 49.5AU (7.41billionkm; 4.60billionmi) at aphelion. Pluto has a 2:3 resonance with Neptune, meaning that Pluto orbits twice round the Sun for every three Neptunian orbits. Kuiper belt objects whose orbits share this resonance are called plutinos. [162] If the Sun–Neptune distance is scaled to 100 metres (330ft), then the Sun would be about 3cm (1.2in) in diameter (roughly two-thirds the diameter of a golf ball), the giant planets would be all smaller than about 3mm (0.12in), and Earth's diameter along with that of the other terrestrial planets would be smaller than a flea (0.3mm or 0.012in) at this scale. [63] Interplanetary environment The zodiacal light, caused by interplanetary dust Inner Solar System". NASA Science: Share the Science. Archived from the original on 10 April 2022 . Retrieved 2 April 2022.

million years, and is thought to be the date of the formation of the first solid material in the collapsing nebula. [9]a b Krasinsky, G. A.; Pitjeva, E. V.; Vasilyev, M. V.; Yagudina, E. I. (July 2002). "Hidden Mass in the Asteroid Belt". Icarus. 158 (1): 98–105. Bibcode: 2002Icar..158...98K. doi: 10.1006/icar.2002.6837. The Sun is composed of roughly 98% hydrogen and helium, [46] as are Jupiter and Saturn. [47] [48] A composition gradient exists in the Solar System, created by heat and light pressure from the early Sun; those objects closer to the Sun, which are more affected by heat and light pressure, are composed of elements with high melting points. Objects farther from the Sun are composed largely of materials with lower melting points. [49] The boundary in the Solar System beyond which those volatile substances could coalesce is known as the frost line, and it lies at roughly five times the Earth's distance from the Sun. [3]

The Solar System lies well outside the star-crowded environs of the Galactic Center. Near the center, gravitational tugs from nearby stars could perturb bodies in the Oort cloud and send many comets into the inner Solar System, producing collisions with potentially catastrophic implications for life on Earth. The intense radiation of the Galactic Center could also interfere with the development of complex life. [232] Stellar flybys that pass within 0.8 light-years of the Sun occur roughly once every 100,000years. The closest well-measured approach was Scholz's Star, which approached to 52 +23 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. van Albada, T.S.; Baker, Norman (1973). "On the Two Oosterhoff Groups of Globular Clusters". The Astrophysical Journal. 185: 477–498. Bibcode: 1973ApJ...185..477V. doi: 10.1086/152434.IAU Planet Definition Committee". International Astronomical Union. 2006. Archived from the original on 3 June 2009 . Retrieved 1 March 2009. Ekers, Ron. "IAU Planet Definition Committee". International Astronomical Union. Archived from the original on 3 June 2009 . Retrieved 13 October 2008. 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. Batygin, Konstantin; Brown, Michael E. (20 June 2010). "Early Dynamical Evolution of the Solar System: Pinning Down the Initial Conditions of the Nice Model". The Astrophysical Journal. 716 (2): 1323–1331. arXiv: 1004.5414. Bibcode: 2010ApJ...716.1323B. doi: 10.1088/0004-637X/716/2/1323. S2CID 7609851.