In 2015, scientists learned about the giant red "whale" on Pluto. A group of Japanese researchers believe that this dark region could be the mark of a giant blow. By the way, thanks to the same impact, the huge plutonian moon Charon was formed, scientists are sure.
The surface of Pluto - the largest object in the Kuiper Belt, a ring of icy bodies beyond Neptune's orbit - has remained a mystery for decades. In 2015, NASA's New Horizons spacecraft captured high-resolution photographs of complex features in Pluto's landscape as it landed in July 2015. Through this mission, we know that Pluto has icy mountains, blue skies, a heart-shaped 1000 km wide nitrogen glacier, and possibly an underground ocean.
One of the most prominent features of the landscape on Pluto is informally called the Cthulhu region or "whale". The region of Cthulhu is cratered, which means it is billions of years old - much more than the craterless young heart it borders on. Scientists say that tholins, complex hydrocarbons, are responsible for the region's reddish hue.
Cthulhu region. NASA
To find out how the whale got its color, Yasuhito Sekine of the University of Tokyo, Japan, experimented with heating organic molecules (such as formaldehyde) that were present in forming Pluto shortly after the formation of the solar system. Sekine discovered that it was possible to create the same dark reddish color by heating the solution above 50 degrees Celsius for several months.
Meanwhile, Hidenori Genda of the Tokyo Institute of Technology conducted computer simulations of a giant impact on Pluto. Genda found out that the impact that created the moon Charon, which is only 2 times smaller than Pluto, could have formed a huge pool of hot water near the equator of a celestial body. When the pool cooled down, reddish complex organic matter could form.
However, Kelsey Singer of the Southwest Research Institute in Colorado considers the theory unlikely. It cannot be, says Singer, that the whale has remained unchanged for 4 billion years.
Singer believes the explanation for the whale's coloration is dark material from methane, processed by radiation on Pluto's surface or atmosphere.
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