Why Is Pluto Colder Than It Should Be?

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One of our favorite dwarf planets is incredibly far away, and its frigid temperatures are not surprising. Pluto is, on average, 40 times as far away from our sun as we are, which means that there’s not a lot of sunlight reaching its surface. However, the data collected by the New Horizons flyby in 2015 suggests that the dwarf planet is much colder than we actually imagined, in fact, 50 degrees Fahrenheit colder than scientists had expected. But why is Pluto colder than it should be?

The reason for Pluto being colder, according to a paper published in the journal Nature, could be because of something that we hadn’t seen before in our solar system, which is a haze of hydrocarbons, which are solid particles. On Earth, these particles are gases located in our atmosphere, which helps regulate the temperature.

The James Webb Space Telescope is to launch in 2019, and it should be able to discover whether the theory scientists have set is correct or not.

“This is kind of a new regime of the climate of planets,” lead author Xi Zhang, a scientist at the University of California, Santa Cruz, said to Space.com. “We never saw this before.”

Scientists hoped to find an explanation to the first New Horizons discovery, so Zhang and his colleagues took a look at a second stumper from the flyby. They discovered an onion-shaped positioning of around 20 layers of haze made up of soot-like particles that were surrounding Pluto. Their theory is that large, solid particles inside the layers of haze could “bounce energy” back into space in the form of infrared radiation. When scientists ran calculations again, taking that occurrence into account, they resulted in temperature estimates that matched the data gathered by New Horizons.

If the hypothesis is correct, those haze particles may share similarities with what scientists found in the atmosphere around Titan, Saturn’s satellite, which is carbon-containing compounds. Still, scientists haven’t yet identified what’s behind Pluto’s haze. Moreover, on Titan, the thermostat is still influenced by gases, same as it is here on Earth.

Infrared radiation, though, is very easy to spot when searching with the right equipment, and that’s definitely the case with the James Webb Space Telescope, set to launch in 2019. It will start gathering that sort of scientific data, which means scientists could test it on Pluto, and perhaps one day they will discover the real reason behind why Pluto is colder than it should be.

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