How did Pluto and its largest moon, Charon, form? This is what a recent study published in Nature Geoscience hopes to address as an international team of researchers led by the University of Arizona (U of A) investigated a new process that could challenge longstanding hypotheses regarding how Pluto and Charon formed. The reason for the debate is Charon’s size is quite large for a moon compared to its parent planet (or dwarf planet in this case), and scientists have presented a plethora of reasons for how Charon orbited Pluto.
For the study, the researchers used U of A’s advanced computer models to simulate potential scenarios that could explain how Charon formed, as scientists have long hypothesized it formed how the Earth and Moon formed, from a collision of a large object. However, the researchers discovered that when including the amount of rock and ice that Pluto and Charon are comprised of, the Earth-Moon model doesn’t quite work. Instead, the simulations propose that Pluto and Charon briefly stuck together after colliding and separated into the two planetary bodies we see today.
"Most planetary collision scenarios are classified as 'hit and run' or 'graze and merge.' What we've discovered is something entirely different – a 'kiss and capture' scenario where the bodies collide, stick together briefly and then separate while remaining gravitationally bound," said Dr. Adeene Denton, who is a NASA Postdoctoral Researcher at the Southwest Research Institute (SwRI) and lead author of the study.
Simulation snapshot of Pluto and Charon during “kiss-and-capture” scenario that could explain their formation. (Credit: Robert Melikyan and Adeene Denton)
Going forward, the researchers aspire to analyze the tidal forces that both Pluto and Charon exuded from each other when they were orbiting much closer than today, which could help explain Pluto’s unique geological surface features. Additionally, new insights could offer clues for how other binary systems form, as well.
What new discoveries about the formation of Pluto and Charon will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Geoscience, EurekAlert!, University of Arizona
Featured Image: Composite image of Pluto (bottom) and Charon (top). (Credit: NASA/JHUAPL/SwRI)
