Pluto’s Red Region: A Scientific Mystery

What color is Pluto, The Planet? 

The answer revealed from NASA’s New Horizon Spacecraft’s data, turns out to be shades of reddish-brown. Spacecraft created history in 2015, passing by Pluto and sending back seminal images of the dwarf planet and its moon, before passing them back to Earth.

The red regions were thought to be caused by molecules – Tholins, organic compounds formed after the interaction of cosmic rays or ultraviolet rays with the methane in Pluto’s atmosphere.

A new study published in the journal Icarus suggests that Tholins alone are likely not the only cause of red patches on the planet. A team guided by Delft University of technology’s Marie Fayolle put efforts to remake Tholins in a lab, but unable to fully repeat the same process which gives the similar red color of Pluto’s “Cthulhu Macula” plain, a massive region of what bears resemblance like rusty dirt.

In the study, scientists figure out how they replicate Tholins. Actually, they are various kinds of “complex organic gunk” which form from straightforward chemical processes, consisting of sunlight, molecular nitrogen or methane, and high energy particles from space. As Pluto has these elements in its atmosphere, scientists think that tholins begin Pluto’s crimson coloration. 

After studying, Fayolle and her team put out a note,

”From recreated reflectance spectra and contrast with New horizon’s data, some tholins replicate the photometric level in the near-infrared. However, a misfit of red visible slope still rests and absorption bands of tholins in spectra are not there in those captured by New Horizons instruments.”

What’s this mean exactly?

It means that tholins generated in laboratories absorb additional light than those on Pluto. This doesn’t prevent the existence of Tholins on the planet, scientists advised that more molecules and matter could be at play.

The team says that “The formation of highly porous structures could develop by either sublimation of ices (initially mixed with aerosols) or deposition under Pluto’s weak gravity.”