Our solar system is chock-full of moons besides the one that orbits our own planet, and perhaps one of the most intriguing of them all is Neptune’s moon Triton.
Given just how far away we are from Neptune, it should come as no surprise to anyone that we know little about Triton. In fact, the last time we got anywhere close to it was when NASA’s Voyager 2 spacecraft flew past it almost three decades ago.
Triton is particularly intriguing to planetary scientists because it’s the only known moon in the solar system is an irregular orbit. Triton orbits clockwise around Neptune at a 183-degree angle to the ecliptic of Neptune, on the other hand, its orbital eccentricity is almost zero, as Triton orbits Neptune in a near-perfect circle.
The bizarre circumstances surrounding Triton have caused some scientists to suggest that the moon didn’t form naturally alongside Neptune, but instead that Neptune’s immense gravity captured it from outer space as it drifted too close.
Triton is larger than the dwarf planet Pluto, and it’s worth noting that the two objects share a similar composition. With that in mind, it’s thought that Triton may have once been a Kuiper Belt Object (KBO) before being captured by Neptune at some point in the distant past.