Layers of haze above Pluto, as seen by NASA’s New Horizons spacecraft during its flyby of the dwarf planet in July 2015.

(NASA/JHUAPL/SwRI)

At a Glance

Scientists estimated Pluto's temperature would hover around minus 280 degrees Fahrenheit.Data collected by NASA's New Horizons probe put the temperature some 53 degrees colder than expected, puzzling scientists.A new study explains the discrepancy on the dwarf planet's hydrocarbon particle-laden haze.

Scientistshave been working for the past two years to understand why Pluto's surface temperatures are far colder than expected, and now, a team of astronomers saysthey believe they've solved the mystery.

While it may seem like the answer is obvious— that the dwarf planet is so far from the sun — scientists say the actual temperature is far colder than what hastheoretically been estimated based on distance and other factors.

According to a study published Wednesday in the journal Nature, is the reason for the unexpected cold weather. The findings are exceptional because it means Pluto isunique among solar system planetary atmospheres because its temperature is "controlled primarily by haze particles instead of gas molecules," the study notes.

The discrepancy in the theoretical surface temperature of around minus 280 degrees Fahrenheit and the actual recorded temperature of minus 333 degrees Fahrenheit was revealed during a July 2015flyby of NASA's New Horizons probe. During the same flyby, the probe also picked up images of the haze, something scientists had not detected before.

"It's been a ," lead author Xi Zhang, assistant professor of Earth and planetary sciences at the University of California Santa Cruz, said in a press release. "Pluto is the first planetary body we know of where the atmospheric energy budget is dominated by solid-phase haze particles instead of by gases."

(MORE:)

Using data collected from the probe about the distribution of gas molecules and haze particles, the researchers created models that suggestthe haze not only absorbs solar energy to heat the dwarf planet it alsoemits a great deal of that energy backinto space as infrared radiation because of the hydrocarbon particles.

Zhang noted that the excess infrared radiation should be detectable by the James Webb Space Telescope after its scheduled launch in 2019, helping to confirm the team's findings.