MISSIONS TO NEPTUNE

Int.


Astronomical specifications:

Discovery 
Orbital characteristics:
Distance from Sun 4,498,252,900 km
Perihelion 4444.5 x (106 km)
Aphelion 4545.7 x (106 km)
Orbital Inclination 1.77 deg
Orbital Eccentricity 0.008
Orbital periode round Sun 164.791 years
Orbital Speed 5.477 km/s
Number of moons 13
Rings Yes
Physical characteristics:
Diameter 49,528 km
Surface area 7,700,000,000 km
Volume 6.254 x 1013 km
Mass 1.024 x 1026 kg
Density 1638 kg/cm
Equatorial gravity 11.0 m/s
Escape velocity 23.71 km/s
Rotation period 16.1 hours
Axial tilt 28.58 deg
Surface temperature -200 C (72 K)
Surface Pressure - bars
Atmospheric composition H2 He CH4

Picture of Neptune taken by Voyager 2 during August 16 and 17, 1989, showing off the Great Dark Spot which has since disappeared from the planet's surface.


Early history:

Space race:

Neptune missions:

Name Launch
Date
Launch rocket Weight
(kg)
Mission
Voyager 2 (USA) 20-Aug-77 Titan-Centaur 815 kg Voyager 2 flew by Jupiter on July 9, 1979, Saturn on August 26, 1981, Uranus on January 24, 1986, and Neptune on August 24, 1989. Returned pictures and data.


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