Unexplained Temperature Drop Detected On Neptune


| LAST UPDATE 04/22/2022

By Stanley Wickens
Neptune unexpected temperature drop
All About Space Magazine / Contributor via Getty Images

The mysteries of our solar system are truly endless. So much so, in fact, that the most recent one that has scientists baffled involves the farthest planet in our solar system. Here's what to know.

For the past 17 years, astronomers have been monitoring the ice giant using several ground-based telescopes, and we've learned quite a lot about the distant planet. Like all others of its kind in our celestial neighborhood, it orbits the Sun and has changing seasons. But since Neptune's orbit is 2.8 billion miles (4.5 billion kilometers) away from the Sun, its season lasts a lot longer than ours do here on Earth. One year on Neptune accounts for about 165 years on Earth, making each of its seasons a little over 40 years long. We've managed to discover that it's been summer on the icy planet since 2005, which makes the unexplained temperature drop recently observed on it very puzzling...

solar system Neptune mystery
All About Space Magazine / Contributor via Getty Images
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Astronomers have been tracking the overall temperature in the planet's atmosphere since the southern summer solstice of 2005. After detecting an unexpected decrease in the planet's global temperature, researchers also noticed the planet's south pole is beginning to warm up considerably. An analysis of almost 100 thermal images of the planet shows that large parts of the planet have dropped 14 degrees Fahrenheit (8 degrees Celsius) in temperature from 2003 to 2018. "This change was unexpected," noted Michael Roman, lead author of the recently published study and a postdoctoral research associate at the University of Leicester. "Since we have been observing Neptune during its early southern summer, we expected temperatures to be slowly growing warmer, not colder."

Although they're still not exactly sure what caused the sudden drop in the planet's temperature, researchers have considered a few factors that may have contributed to the phenomenon. "Temperature variations may be related to seasonal changes in Neptune's atmospheric chemistry, which can alter how effectively the atmosphere cools," said Roman. "But random variability in weather patterns or even a response to the 11-year solar activity cycle may also have an effect." But before we can confirm anything, many more observations need to be made about the planet. And considering the fact that Neptune is more than 30 times as far from the Sun as we are, we have a feeling that may take a while. Be sure to stay tuned.

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