Astronomers have long been puzzled by the origin of Charon, the largest moon of dwarf planet Pluto. A new simulation suggests that a collision between Pluto and Charon could explain how it ended up in orbit around its companion. The research proposes a “kiss and capture” scenario, where the two bodies collided at low speed, merged briefly, and then separated without breaking apart.
According to scientists, Charon’s large size relative to Pluto is not compatible with conventional theories of moon formation, including debris accretion or gravitational capture. However, the sizes of the two bodies suggest that a collision could have occurred, similar to the one believed to have formed Earth’s moon. The researchers propose that at speeds around 2,000 miles per hour, Charon would have remained attached to Pluto for about 10 hours before gradually separating.
This scenario is supported by the fact that Pluto and Charon share similar properties, such as being rocky and icy. The research team also notes that the impact could have resurfaced Pluto’s surface and formed its four other known moons, including Nix, Styx, Kerberos, and Hydra. Further study of Pluto may provide evidence for this “kiss and capture” event, potentially challenging our current understanding of moon formation.
The discovery offers a new twist on the physics of collisions, suggesting that even large bodies can be captured without merging entirely. With ongoing research and potential future missions to Pluto, scientists hope to verify or refute this theory, shedding more light on the mysterious dance between Pluto and Charon.
Source: https://www.nytimes.com/2025/01/08/science/pluto-moon-kiss-charon.html