Unlike the commonly accepted explanation for how the Earth’s moon came to be billions of years ago, Pluto and its largest moon, Charon, seem to have a far less tumultuous origin.

Recent computational simulations indicate that the dwarf planet and the object that impacted it underwent a distinctive kind of cosmic interaction. Normally, planetary collisions are classified as either “hit-and-runs,” where one celestial body merely brushes against another and continues its trajectory, or “graze-and-merges,” in which two bodies collide and fuse into a single entity. Nevertheless, a new research led by Adeene Denton, a NASA postdoctoral fellow at the Southwestern Research Institute, posits an alternative scenario: a “kiss-and-capture” event.

The research suggests that during their collision, Pluto and Charon likely adhered together for a time, rotating as a singular mass through the cosmos. Ultimately, they separated, with Charon achieving a stable orbit around Pluto. Notably, this mechanism would have retained much of the primordial material from both bodies.

This impact might have produced sufficient heat to generate a subterranean ocean on Pluto, according to Denton, as reported by *Mashable*. This discovery corroborates earlier theories proposing that Pluto could conceal liquid water beneath its icy exterior. The study was published in the journal *Nature Geoscience*.

### A Fresh Insight on Pluto and Charon

Since NASA’s *New Horizons* craft passed by Pluto nearly a decade ago, researchers have developed a heightened understanding of the dwarf planet’s intricacies. Once perceived as a frigid, desolate rock at the solar system’s boundary, Pluto has emerged as a geologically rich world, showcasing mountains, ice sheets, pits, cliffs, cracks, and valleys.

Discovered in 1978 by the U.S. Naval Observatory, Charon, Pluto’s largest moon, spans about 750 miles in diameter, making it particularly large relative to its parent planet, being approximately half the size of Pluto.

Earlier models proposed that Charon originated in a manner akin to that of Earth’s moon. In that hypothesis, a Mars-sized object collided with a young Earth, ejecting debris that eventually formed the moon. However, instead of creating a debris disk, Pluto and its impactor may have briefly produced two fluid-like masses that exchanged material prior to Charon being ejected into orbit.

### Enhanced Simulations Illuminate New Findings

Denton’s team utilized advanced computational simulations to consider the structural integrity of rock and ice, the main constituents of Pluto and other Kuiper Belt objects. This method demonstrated that Pluto and its impactor did not merge, shed considerable material, or turn into fluid masses, as previous theories indicated. Instead, the “kiss-and-capture” scenario surfaced as a viable explanation for the formation of Charon.

These findings hold broader significance for the Kuiper Belt, a region beyond Neptune teeming with comets and icy celestial bodies. Researchers now theorize that other objects in this cold expanse may have undergone similar kiss-and-capture encounters. The relatively large dimensions of moons and moonlets in this area, in contrast to other solar system regions, bolster this notion. Additionally, such collisions could produce enough heat to foster underground oceans, suggesting that other distant entities may also possess concealed pools of liquid water.

“Eighty percent of the largest Kuiper Belt objects have a sizable satellite akin to Charon,” Denton commented in an email. “This mechanism might have been prevalent throughout the outer solar system in its early stages.”

### A Glimpse into the Outer Solar System

These findings not only question conventional models of moon formation but also pave the way for new insights into the dynamics of the outer solar system. If kiss-and-capture events were commonplace, they could elucidate the distinctive traits seen in many Kuiper Belt objects and their satellites. Furthermore, the potential existence of underground oceans on these remote worlds presents thrilling opportunities for upcoming exploration and the quest for extraterrestrial life.