Planetary Notes:

Venus, Uranus: anti-clockwise rotation

Venus spins on its axis from east to west, while Uranus is tilted so far over, it's virtually spinning on its side. ... But Venus and Uranus are the exceptions: they have what's known as retrograde rotation, spinning counter to the rotation of the Sun.

Neptune, the blue planet

Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar ... Traces of methane in the outermost regions in part account for the planet's blue appearance. In contrast to the hazy, relatively featureless ..

Triton orbits Neptune in what is known as a retrograde orbit. This means that it orbits Neptune a direction opposite the planet's rotation. It is the only large moon in the Solar System to do this. Astronomers are not quite sure of the reason for this retrograde orbit.

Son of Poseidon
The planet Neptune is surrounded by a system of 8 moons. Most of these are tiny, with diameters of less than 500 miles. One of these moons, however, is quite large and warrants further investigation. This is the moon Triton. It was named after the Greek god Triton, who was the son of Poseidon (Neptune). He is usually portrayed as having the head and body of a man and the tail of a fish. This moon of Neptune was discovered by the British astronomer William Lassell in 1846. Since then it has been visited by only one spacecraft, Voyager 2, in 1989. http://www.seasky.org/solar-system/neptune-triton.html

The Backwards Moon
Triton orbits Neptune in what is known as a retrograde orbit. This means that it orbits Neptune a direction opposite the planet's rotation. It is the only large moon in the Solar System to do this. Astronomers are not quite sure of the reason for this retrograde orbit. Some believe that it condensed this way from the original material of the early solar system. Others think that Triton may have been formed elsewhere and then captured by Neptune's gravity. In fact, many astronomers have noticed that the surface features of Triton, as well as its size, are very similar to what they believe the planet Pluto to look like. Some even wonder if there is some connection between Triton's features and the fact that Pluto actually crosses Neptune's orbit from time to time. Just what that connection might be is anyone's guess at this point.

It's not Pluto, the one with the greatest radius, nor Eris, the one with the greatest mass. Instead, Triton — the largest moon of Neptune — has them both beat. https://www.forbes.com/sites/startswithabang/2018/11/30/triton-not-pluto-or-eris-is-the-kuiper-belts-largest-world/#508b726a630c

Only Earth's Moon, Saturn's Titan, and the four Galilean moons of Jupiter surpassing it.