Neptune II
Nereid [NEER-ee-ed] was discovered in 1949 by astronomer Gerard Kuiper. Nereid is about 340 kilometers (210 miles) in diameter and is so far from Neptune that it requires 360 days to make one orbit. Voyager's best photos of Nereid were taken from about 4.7 million kilometers (2.9 million miles), and show that its surface reflects about 14 percent of the sunlight that strikes it, making it somewhat more reflective than Earth's Moon, and more than twice as reflective as Proteus. Nereid's orbit is the most eccentric in the solar system. Its distance to Neptune ranges from about 1,353,600 km (841,100 miles) to 9,623,700 km (5,980,200 mi).
Discovered by ................................. Gerard Kuiper Date of discovery ...................................... 1949 Mass (kg) ................................................. ? Equatorial radius (km) .................................. 170 Equatorial radius (Earth = 1) .................... 2.6654e-02 Mean density (gm/cm^3) .................................... ? Mean distance from Neptune (km) ................... 5,513,400 Rotational period (days) .................................. ? Orbital period (days) .............................. 360.1362 Mean orbital velocity (km/sec) ......................... 1.12 Orbital eccentricity ................................. 0.7512 Orbital inclination .................................... 27.6° Visual geometric albedo ................................ 0.14 Magnitude (Vo) ......................................... 18.7
Neptune
Triton