One kiss is all it takes, and that is perhaps the case with Pluto and its largest moon, Charon. Since the 1990s, scientists have propagated the belief that Charon formed in a way similar to Earth’s moon— An impact on the main body of the planet that splashed hot molten material into the planet’s orbit, which has aggregated into a natural satellite. However, recent computer simulations provide us with a heartwarming hypothesis. The simulations have suggested that Charon and Pluto formed a pair through a “kiss-and-capture” collision, in which the two bodies briefly came into contact before settling into their current positions.
Planetary scientist Adeene Denton of the Southwest Research Institute in Boulder, Colo., reported the results on January 6 in Nature Geoscience. “They kiss and they say, ‘Yeah, this is it. I want to build a system together with you.’ And then they do.”
Both Pluto and Charon are located in the Kuiper Belt, a ring of frigid celestial bodies at the Solar system’s edge, far from the Sun. According to the team of researchers who ran the simulation, two icy celestial bodies collided billions of years ago. However, the impact united them instead of annihilating one another, forming a spinning pair, a “cosmic snowman.” The bodies then separated quickly but were linked in an orbital system, creating the Pluto-Charon pair we see today.
“Because Pluto is rotating rapidly prior to the collision, and because Charon lies mostly outside of their corotation zone, it is able to ‘push’ Charon off, and Charon starts to slowly migrate out,” said Dr Adeene Denton.
Denton adds that small bodies like Pluto and its moon, Charon, might have collided slowly. The slow impact prevented the complete obliteration of the two celestial bodies; however, some material was exchanged before the two separated and formed a planetary system. Usually, most models consider the colliding parties like fluids and overlook material strength. “What that means is that, because they’re made of rock and ice, they respond the way those materials would under stress, and not like fluids,” said Denton.
The “kiss-and-capture” model can also shed some light upon the geological evolution of both Pluto and Charon— including whether they formed subsurface oceans or not. According to Denton, the impact resulted in heat generation, and as Charon moved further, it led to further heating. This could have possibly started a new geologic era, which we were able to observe through the space probe New Horizon in 2015. She adds that eight of the ten largest Kuiper Belt objects have large satellites like Charon. This indicates that the “kiss-and-capture” events were pretty prolific in the Kuiper Belt across the time of the formation of the Solar System.
Here is a video showing how Pluto’s largest moon, Charon, ended up as a natural satellite of the dwarf planet Pluto.
Copyright @smorescience. All rights reserved. Do not copy, cite, publish, or distribute this content without permission.
