New Research Suggests Pluto Captured its Moon Charon with an Icy Kiss
A Brief Explanation of the Theory
New research proposes that billions of years ago, Pluto may have captured its largest moon, Charon, through a short-lived icy kiss. This theory could explain how the dwarf planet captured a moon that is about half its size. The theory suggests that two frigid worlds in the Kuiper Belt, a ring of icy bodies located at the edge of the solar system, collided and merged for a short time, creating the Pluto/Charon system that exists today.
‘Kiss-and-Capture’ – A New Theory of Moon Capture
This process of capture is referred to as ‘kiss-and-capture’ because the two bodies briefly merged before separating to form two separate entities. While most planetary collision scenarios involve one body obliterating the other, this new theory presents a unique scenario of temporary merging.
The Challenge of Capturing Charon
Pluto’s relationship with Charon has been challenging for scientists to understand due to the small difference in size and mass between the two bodies. Charon is much larger compared to Pluto, with half its size and 12% of its mass. This size similarity makes Pluto/Charon more similar to the Earth/moon system than any other moon in the solar system.
Collisional Capture and the Formation of Pluto and Charon
The prevailing theory suggests that the Pluto/Charon system formed through a collisional capture event, similar to how a massive body is believed to have collided with Earth, resulting in the formation of our moon. A massive collision occurred between two icy bodies, causing them to stretch and deform in a fluid-like manner. However, the structural strength of the colder icy and rocky bodies was not previously considered in these simulations.
The Role of Material Strength
When researchers accounted for the material strength of Pluto and Charon in their simulations, they discovered an unexpected result. Charon did not penetrate deep enough into Pluto to merge with it, as would be expected with fluid bodies. This resulted in both bodies remaining structurally intact during their brief merger.
The ‘Kiss’ and Brief Merger
During the ‘kiss-and-capture’ event, the merge between Pluto and Charon only lasted for approximately 10 to 15 hours. Charon then began its slow outward migration towards its current position. The team believes this initial collision occurred early in solar system history, billions of years ago.
Implications and Future Research
This new research raises questions about the thermal state of Pluto and how it may have influenced the formation of oceans on both Pluto and Charon. Further investigation will be conducted to determine if the ‘kiss-and-capture’ process applies to other large moons in the Kuiper Belt. Additionally, the long-term tidal evolution of Charon will be studied to confirm the formation theory. Overall, this research provides new insights into the formation and structure of icy worlds in the outer regions of the solar system.
References
– Denton, A. et al. (2020). Nature Geoscience, Effect of material strength on giant impacts and Pluto-Charon formation. – University of Arizona. (2020, January 6). New research suggests Pluto should be reclassified as a planet. ScienceDaily.
