" The seventh of eight satellites of its parent planet, it is the only one that is regularly shaped and the largest as well.
Though discovered by William Lassell in 1846, little was known of it until August 25, 1989, when Voyager 2 flew within 24,000 miles of it. It revolves so slowly that each of its seasons lasts 40 years, and its unique landscape was created by a phenomenon termed "icy volcanism." The seventh of eight satellites of its parent planet, it is the only one that is regularly shaped and the largest as well. In addition, it is the largest solar system satellite that moves in a retrograde orbit. FTP, identify this largest moon of Neptune.
Though discovered by William Lassell in 1846, little was known of it until August 25, 1989, when Voyager 2 flew within 24,000 miles of it.
Triton