Nereid is Neptune's outermost known moon. Nereid's orbit is about 3.4 million miles from Neptune and has a diameter of 211 miles. The name Nereid comes from any one of the sea nymphs, who are the 50 daughters of Nereus and Doris. Nereid was discovered by Kuiper in 1949. Nereid has the most eccentric orbit of any planet or moon in our solar system. Its distance from Neptune ranges from 841,000 miles to 5.8 million miles. The cause of this may be that it is a captured asteroid.