Astronomers have long debated how Pluto acquired its large moon Charon. Now, new research suggests that the two bodies formed through a rare “kiss and capture” collision about 4 billion years ago. The study’s lead author, Adeene Denton, says that Pluto and Charon are distinct from other celestial bodies in terms of their composition and structure.
Unlike Earth’s moon, which is thought to have formed after a Mars-size object collided with our planet, the Pluto-Charon system likely remained intact during the impact. Instead, the two bodies spun together to form a single object before separating into their current binary system.
The researchers used advanced simulations to model the collision and determine the impact momentum exchanged between Pluto and Charon. They found that both bodies remained largely intact due to their composition, sticking together to form a “snowman-like” figure before separating and rotating as one body.
This new type of celestial collision sheds light on how planets form and evolve, particularly in the outer reaches of our solar system. The research also suggests that Pluto may have a subsurface ocean beneath its icy crust, which could be heated by tidal forces caused by Charon’s orbit.
Source: https://edition.cnn.com/2025/01/10/science/pluto-charon-kiss-capture-collision/index.html