According to a compositional analysis, the dwarf planet Pluto and its largest moon, Triton, may have had a common ancestor before splitting apart. Both Pluto and Triton are ice moons that are smaller than Earth's, have comparable densities, and seem to have formerly had subterranean oceans.
Triton is the only huge moon in the solar system to orbit in the opposite direction from its planet, which is unusual given that it is around 50% more massive than Pluto. Because moons that formed with Neptune should mirror its spin, this has led to speculation that it may have come from the Kuiper belt, a region of ice objects like Pluto that exist beyond Neptune.
Now, Kathleen Mandt and her colleagues at NASA's Goddard Space Flight Center in Maryland have gone one step further and proposed that Pluto and Triton formed near one another before the solar system calmed down. Mandt explains, "They most likely developed in the same location, which would have been either closer or farther away from where the Kuiper belt is presently."
According to the team's analysis of earlier data on the two bodies, they both contain significant levels of nitrogen as well as trace amounts of carbon monoxide and methane, which may have collected in the outer parts of the early nebula that surrounded our sun 4.5 billion years ago.
This implies that they both originated in nitrogen-rich, cold outer regions of the early solar system. However, like several known icy comets like comet C/2016 R2 (PanSTARRS), which may have originated from a comparable area, they too have low water contents. According to Mandt, "they had to have originated beyond the water-ice line," which is the distance from the sun at which water would turn into snow or ice.
where Jupiter is today, and Triton, far left, and Pluto contain comparable concentrations of several essential elements. According to her, based on their similar compositions and dynamical modeling of the solar system, the two bodies would have formed no more than 30 astronomical units (AU) from the sun and within 1 to 5 AU, or sun-Earth distances, of one another. Then, for some reason, Triton was expelled from this area and caught in Neptune's grasp. One theory is that early in the solar system's first 10o million years or more, the massive planets shifted closer to the sun, potentially upsetting the orbits of some things like Triton.
Paul Schenk of the Lunar and Planetary Institute in Texas argues that determining the origins of Triton and Pluto could help us understand the formation of our solar system. He claims that "there is an evidence there was more than one Pluto." "Other bodies of comparable size and makeup were probably lost as well.
@ Bhautik Thummar