Planet Neptune Data

Orbital Elements

Semimajor Axis: 30.0699 AU

Eccentricity: 0.00859

Inclination: 1.7700°

Argument of Perifocus: 273.2°

Longitude of Ascending Node: 131.784°

Mean Motion: 0.0060200767° per day

Time of Periapsis: 2046 Nov 13

Orbital Period: 163.72321 years

Mass: 17.204 M_E

Equatorial Radius (1 bar): 3.8830 R_E

Rotational Inclination: 29.56°

Rotational Period: 17 hours

Satellites

Satellite Name	Orbital Semimajor Axis (km)	Orbital Period (days)	Mass (kg)	Discovery
Satellite Name	Orbital Semimajor Axis (km)	Orbital Period (days)	Mass (kg)	Discoverer Name	Announcement Date
Naiad	4.8227·10⁴	0.294396	~1.9·10¹⁷	Voyager 2 Team	1989
Thalassa	5.0075·10⁴	0.311485	~3.5·10¹⁷	R. Terrile	1989
Despina	5.2526·10⁴	0.334655	~2.1·10¹⁸	S. Synnott and the Voyager 2 Team	1989
Galatea	6.1953·10⁴	0.428745	2.12·10¹⁸	S. Synnott and the Voyager 2 Team	1989
Larissa	7.3548·10⁴	0.554654	~4.2·10¹⁸	H. Reitsema, et al.	1989
Proteus	1.17647·10⁵	1.122315	~5·10¹⁹	S. Synnott and the Voyager 2 Team	1989
Triton	3.5476·10⁵	5.876854	2.147·10²²	W. Lassell	1846
Nereid	5.5134·10⁶	360.13619	~3.1·10¹⁹	G. P. Kuiper	1949
Halimede	1.5728·10⁷	1879.7	~9·10¹⁶	J. J. Kavelaars, et al.	2003 Jan 13
Sao	2.2422·10⁷	2914.1	~9·10¹⁶	J. J. Kavelaars, et al.	2003 Jan 13
Laomedeia	2.3571·10⁷	3167.9	~9·10¹⁶	J. J. Kavelaars, et al.	2003 Jan 13
Psamathe	4.6695·10⁷	9115.9	~1.5·10¹⁶	M. Holman, et al.	2003 Sep 3
Neso	4.8387·10⁷	9374.0	~9·10¹⁶	M. Holman, et al.	2003 Sep 30

1 AU = 1.49597870691·10¹¹ m 1 year = 365.25 days = 31557600 s
1 M_E = 5.9742·10²⁴ kg 1 R_E = 6.378136·10⁶ m

The URL of this page is: http://www.princeton.edu/~willman/planetary_systems/Sol/Neptune

This page was last updated: 2007 January 30

You may contact Alex at: willman@Princeton.EDU

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