Triton is the largest of Neptune's 13 moons. It is unusual because it is the only large moon in our solar system that orbits in the opposite direction of its planet's rotation―a retrograde orbit. A global color mosaic of Triton taken in 1989 by Voyager 2 during its flyby of the Neptune system. #nature #astronomy #nasa

<p><br></p><p><b>Discovery</b></p><p>Triton was discovered on Oct. 10, 1846 by British astronomer William Lassell, just 17 days after Neptune itself was...See more