Pluto’s Weirdly Big Moon May Have Come From A ‘Kiss And Capture’ – Forbes
Pluto as seen from New Horizons spacecraft, 2015. (Photo by Heritage Space/Heritage Images via Getty … [+] Images)Pluto has five moons, but Charon stands out from the rest. Charon is half the size of Pluto, “making it the largest known moon relative to its parent planet in our solar system,” NASA notes. So how did Pluto get its chonky companion? A new study suggests an unusual mechanism called “kiss and capture.”The “kiss and capture” concept for Charon’s formation detours from previous ideas about how the moon came to be. “By considering something planetary scientists had overlooked over decades—the structural strength of cold, icy worlds—researchers have discovered an entirely new type of cosmic collision,” the University of Arizona said in a statement on Jan. 6. NASA postdoctoral fellow Adeene Denton led the new study, published in the “Nature Geoscience” journal on Monday.Scientists have been contemplating Pluto’s moons for years. The other four moons—Nix, Hydra, Kerberos and Styx—are much smaller than Charon. One idea is that Pluto got its moon system when a massive object smashed into the dwarf planet. The resulting debris then formed into the moons. This hypothesis was nicknamed the “Big Whack.”Tthe dwarf planet Pluto (R) and Charon are shown July 11, 2015. (Photo by NASA/JHUAPL/SWRI via Getty … [+] Images)Researchers studying Pluto and Charon have long drawn a parallel to how Earth got its moon. The prevailing thought is that a Mars-sized body collided with Earth around 4.5 billion years ago and “flung enough molten and vaporized debris into space to create the moon,” according to NASA. Denton’s research suggests this isn’t how Pluto got Charon. “Pluto and Charon are different—they’re smaller, colder and made primarily of rock and ice,” said Denton. “When we accounted for the actual strength of these materials, we discovered something completely unexpected.”The team ran a series of impact simulations that showed a proto-Charon striking Pluto (the “kiss”) and then sticking to it like a snowman (the “capture”). The two bodies would have stayed mostly intact and then later separated into Pluto and its biggest moon. The computer models also agree with how Charon orbits Pluto, making it a tidy and compelling theory for the moon’s origin.Pluto was famously demoted from a full planet to a dwarf planet in 2006. The International Astronomical Union handles the official naming and classification of planets and other celestial bodies. “A dwarf planet is an object in orbit around the sun that is large enough to pull itself into a nearly round shape but has not been able to clear its orbit of debris,” the IAU said in an explainer. “Generally, dwarf planets are smaller than Mercury.” That sums up Pluto.The researchers plant to study how the “kiss and capture” process affected Pluto over time. “We’re particularly interested in understanding how this initial configuration affects Pluto’s geological evolution,” said Denton. “The heat from the impact and subsequent tidal forces could have played a crucial role in shaping the features we see on Pluto’s surface today.”NASA’s New Horizons mission visited Pluto in 2015, giving us an unprecedented close-up view of the planet and its moons. “The New Horizons images and data surprised scientists by showing both Pluto and Charon to be complex bodies despite their small size and cold temperatures,” NASA said. Pluto may not be a full-fledged planet, but it continues to fuel fascination and research. As it turns out, the story of Pluto and Charon may have been more like a dance than a full-throttle collision.One Community. Many Voices. Create a free account to share your thoughts. Our community is about connecting people through open and thoughtful conversations. We want our readers to share their views and exchange ideas and facts in a safe space.In order to do so, please follow the posting rules in our site’s Terms of Service. We’ve summarized some of those key rules below. Simply put, keep it civil.Your post will be rejected if we notice that it seems to contain:User accounts will be blocked if we notice or believe that users are engaged in:So, how can you be a power user?Thanks for reading our community guidelines. Please read the full list of posting rules found in our site’s Terms of Service.
