Nettuniu (pianeta)

Nettuniu hè l'ottava pianeta in u sistemu sulare. Hè a quarta pianeta più larga per via di u diamitru.

Nettuniu Astronomical symbol for Neptune.
Neptune from Voyager 2
Nettuniu da Voyager 2 incù Great Dark Spot à manca è Small Dark Spot à dritta.
Discovery
Scuparta da
Data di scuparta23 Sittembre di u 1846[1]
Designations
PronunciaTemplate:IPAc-en[2]
AdjectiveNettunianu
Orbital characteristics[7][8]
Epoch J2000
Aphelion4,553,946,490 km
30.44125206 AU
Perihelion4,452,940,833 km
29.76607095 AU
Acchisi mezu maggiore4,503,443,661 km
30.10366151 AU
Eccentricità0.011214269
Periodu orbitale60,190.03[3] days
164.79 years
89,666 Neptune solar days[4]
Periodu sinodicu367.49 day[5]
Vitezza orbitale5.43 km/s[5]
Anumalia media267.767281°
Inclinazione1.767975° to Ecliptic
6.43° to Sun’s equator
0.72° to Invariable plane[6]
Longitudine di u nodu ascindente131.794310°
Argument of perihelion265.646853°
Satelliti13
Physical characteristics
Radiu Equatoriale24,764 ± 15 km[9][10]
3.883 Earths
Polar radiu24,341 ± 30 km[9][10]
3.829 Earths
Flattening0.0171 ± 0.0013
Surface area7.6183×10Template:Val/delimitnum km2[3][10]
14.98 Earths
Volume6.254×10Template:Val/delimitnum km3[5][10]
57.74 Earths
Massa1.0243×1026 kg[5]
17.147 Earths
5.15×10Template:Val/delimitnum Suns
Densità media1.638 g/cm3[5][10]
Equatorial surface gravity11.15 m/s2[5][10]
1.14 g
Escape velocity23.5 km/s[5][10]
Periodu di rotazione siderale0.6713 day[5]
16 h 6 min 36 s
Vitezza di rotazione equatoriale2.68 km/s
9,660 km/h
Axial tilt28.32°[5]
Polu Nordu ascensione drittaTemplate:RA[9]
299.3°
Polu nordu declinazione42.950°[9]
Albedo0.290 (bond)
0.41 (geom.)[5]
Surface temp. min mean max
1 bar level 72 K[5]
Template:Convert/barTemplate:Convert/test/Aon 55 K[5]
magnitude apparente8.02 to 7.78[5][11]
Diamitru angulare2.2–2.4[5][11]
Atmosphere[5]
Scale height19.7 ± 0.6 km
Composizione
80±3.2%hydrogen (H2)
19±3.2%helium (He)
1.5±0.5%methane (CH4)
~0.019%hydrogen deuteride (HD)
~0.00015%ethane (C2H6)

Ices:

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Da vede dinùMudificà

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  1. Hamilton, Calvin J. (4 Aostu di u 2001). "Nettuniu". Views of the Solar System. Retrieved 13 Aostu di u 2007. Check date values in: |accessdate=, |date= (help)
  2. Walter, Elizabeth (21 Aprile di u 2003). Cambridge Advanced Learner's Dictionary (2nd ed.). Cambridge University Press. ISBN 978-0-521-53106-1. Check date values in: |date= (help)
  3. 3,0 3,1 Munsell, K.; Smith, H.; Harvey, S. (13 November 2007). "Neptune: Facts & Figures". NASA. Retrieved 14 August 2007.
  4. Seligman, Courtney. "Rotation Period and Day Length". Retrieved 13 August 2009.
  5. 5,00 5,01 5,02 5,03 5,04 5,05 5,06 5,07 5,08 5,09 5,10 5,11 5,12 5,13 5,14 Williams, David R. (1 Sittebmre di u 2004). "Neptune Fact Sheet". NASA. Retrieved 14 August 2007. Check date values in: |date= (help)
  6. "The MeanPlane (Invariable plane) of the Solar System passing through the barycenter". 3 April 2009. Retrieved 10 April 2009. (produced with Solex 10 written by Aldo Vitagliano; see also Invariable plane)
  7. Yeomans, Donald K. "HORIZONS Web-Interface for Neptune Barycenter (Major Body=8)". JPL Horizons On-Line Ephemeris System. Retrieved 8 August 2007. At the site, go to the "web interface" then select "Ephemeris Type: Elements", "Target Body: Neptune Barycenter" and "Center: Sun".
  8. Orbital elements refer to the barycentre of the Neptune system, and are the instantaneous osculating values at the precise J2000 epoch. Barycentre quantities are given because, in contrast to the planetary centre, they do not experience appreciable changes on a day-to-day basis from the motion of the moons.
  9. 9,0 9,1 9,2 9,3 Seidelmann, P. Kenneth; Archinal, Brent A.; A'Hearn, Michael F.; et al. (2007). Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements: 2006. Celestial Mechanics and Dynamical Astronomy. pp. 155–80. Bibcode:2007CeMDA..98..155S. doi:10.1007/s10569-007-9072-y.
  10. 10,0 10,1 10,2 10,3 10,4 10,5 10,6 Refers to the level of Template:Convert/barTemplate:Convert/test/A atmospheric pressure
  11. 11,0 11,1 Espenak, Fred (20 July 2005). "Twelve Year Planetary Ephemeris: 1995–2006". NASA. Retrieved 1 March 2008.