The global temperature of Neptune is changing in an unexpected way. Neptune has seen a significant climatic shift in the previous 17 years. And, for the first time, mankind is not to blame, even if we don’t know what’s behind it. Neptune’s global temperature decreased 8 degrees Celsius (14.4 degrees Fahrenheit) between 2003 and 2018, according to The Planetary Science Journal when the planet’s southern hemisphere began its summer season (which lasts about 40 years, like every season on Neptune). However, by 2020, the South Pole has warmed by 11 degrees Celsius (19.8 degrees Fahrenheit) compared to 2018.
Dr. Michael Roman, a postdoctoral research associate at the University of Leicester, stated in a statement that the development was unexpected. “We anticipated temperatures to gradually get warmer, not cooler since we’ve been studying Neptune during its early southern summer.” Neptune’s average temperature is around –220 °C (–364 °F), and the heat it does have is generated by internal processes. Neptune emits 2.61 times the amount of energy it gets from the Sun. As a result, observing the seasons offers information about the evolution of the planet’s atmosphere. Some expectations have been thrown out the window as a result of these new results.
For example, scientists have long known that Neptune has a warm polar vortex (at least warm for Neptune) relative to the rest of the planet, but they had no idea it would endure such drastic temperature swings. It’s unclear what’s causing the problem. Variations in the planet’s stratosphere’s chemical makeup, solar activity, or even weather patterns might all be factors. Neptune’s storms have also been a little strange lately.
“Our data only cover about half of a Neptune season, so no one expected to find such massive and quick shifts,” said Glenn Orton, a senior research scientist at Caltech’s Jet Propulsion Laboratory in the United States. Since the Voyager 2 in 1989, humanity has not had a close encounter with Neptune. All measurements of the planet’s temperature are taken on (or near) Earth. The VLT Imager and Spectrometer for Mid-Infrared (VISIR) on Chile’s Very Large Telescope are well-suited for this purpose, and the team merged this data with views from NASA’s Spitzer Space Telescope as well as observations from other telescopes in Chile and Hawaii.
“This sort of study is only conceivable with sensitive infrared photos from huge telescopes like the VLT that can clearly detect Neptune, and they have only been accessible for the past 20 years or so,” said co-author and University of Leicester professor Leigh Fletcher. NASA’s JWST and other observatories set to launch in the future years will give a more thorough view of Neptune, potentially revealing the riddle of its climate.
