Triton is known to be unusual because it does not orbit towards the same direction that Neptune orbits. This means that while Neptune follows a certain direction, it can be expected that Triton is going the opposite direction. Its size and the way that it looks has fascinated a lot of astronomers for a long period of time.
There is just something about this moon that makes this interesting. It may be because of its hard surface or the fact that it is one of the coldest places in the solar system. Some people are still speculating whether this is a place that people can live in the future or not.