New Discovery in Pluto's Heart Suggests It Was Created From One Billion Comets
It's strange to think that our first close-up images of Pluto only came in 2015, a whopping 85 years after it was discovered. In fact, it took until the 2015 New Horizons mission for scientists to identify Pluto's Heart, also known as the Tombaugh Regio, a 990-mile-wide heart-shaped area of lighter material on Pluto's surface. It turns out that The Heart may be more than a cool formation—a new study says that it provides evidence that Pluto was formed from around a billion comets.
The left part of the Heart, an area called the Sputnik Planitia, is a giant, frozen glacier made of nitrogen. According to Chris Glein, a scientist from the Southwest Research Institute, this part of the Heart may be the key to understanding how Pluto came to be:
"We found an intriguing consistency between the estimated amount of nitrogen inside the glacier and the amount that would be expected if Pluto was formed by the agglomeration of roughly a billion comets or other Kuiper Belt objects similar in chemical composition to 67P, the comet explored by Rosetta."
Pluto hangs out in the Kuiper Belt, the cold, outer ring of icy comets and asteroids that circle the sun outside of Neptune's orbit, so it's not hard to see how smaller celestial bodies in the Belt might have come together to form a larger one.
What's interesting is that scientists were able to figure this out based on chemistry alone:
"Using chemistry as a detective's tool, we are able to trace certain features we see on Pluto today to formation processes from long ago," says Glein. "This leads to a new appreciation of the richness of Pluto's 'life story,' which we are only starting to grasp."
Fun fact: Pluto's Heart is northeast of the Cthulhu Macula, a whale-shaped region named for H.P. Lovecraft's infamous Elder God Cthulhu, partly because Pluto played such a big role in Lovecraft's stories.