February 8, 2022
The gas giant planet Neptune hosts a moon named Triton. This is the largest moon of Neptune, but it has the unusual characteristic of orbiting Neptune in the opposite direction of all the other moons. Moons typically orbit a planet in the same direction that the planet rotates – in this case counterclockwise. The fact that Triton orbits Neptune in a clockwise direction suggests that it was not created at the same time as Neptune, and instead was captured by the planet’s gravity after formation.
This is a composite image showing Neptune as it would look from the surface of it’s moon Triton. This image was created using images taken from the Voyager spacecraft. Image credit: NASA