Naiad, the last satellite discovered, is about 54 kilometers (33 miles) in diameter and orbits Neptune every 7 hours and 6 minutes about 23,200 kilometers (14,400 miles) above the clouds. It is irregularly shaped and shows no sign of any geological modification. Naiad circles the planet in the same direction as Neptune rotates, and remains close to Neptune's equatorial plane. The above image has been smeared so that Naiad appears highly elongated.
Discovered by Voyager 2
Date of discovery 1989
Mass (kg) ?
Equatorial radius (km) 29
Equatorial radius (Earth = 1) 4.5469e-03
Mean density (gm/cm^3) ?
Mean distance from Neptune (km) 48,000
Rotational period (days) ?
Orbital period (days) 0.294396
Mean orbital velocity (km/sec) 11.86
Orbital eccentricity 0.0003
Orbital inclination (degrees) 4.74
Visual geometric albedo 0.06
Magnitude (Vo) 24.7