Planet Neptune Suddenly Experienced A Surprising Increase In Temperature, What's Up?

Neptune suddenly surprised astronomers with its unprecedented temperature change. (photo: doc. NASA)

JAKARTA - Neptune suddenly surprised astronomers with an unprecedented temperature change. The planet is known as the ice giant.

An international team of astronomers has used ground-based telescopes, including the European Southern Observatory's Very Large Telescope (VLT ESO), to track the temperature of Neptune's atmosphere over a 17-year period.

They found a surprising drop in Neptune's global temperature followed by dramatic warming at its south pole. The outermost planet of the Solar System apart from Pluto is more than 30 times the distance from the Sun from Earth.

“This change was unexpected. Because we have been observing Neptune during the early southern summer, we expect temperatures to slowly get warmer, not colder," said lead author Dr Michael Roman from the University of Leicester in an official statement to the media, Tuesday, April 12.

Like Earth, Neptune has seasons as it orbits the Sun. However, Neptune's seasons last about 40 years, with one Neptune year lasting 165 Earth years.

Astronomers are eager to see how temperatures change after the southern summer solstice. They looked at nearly 100 thermal-infrared images of Neptune, taken over a 17-year period, to gather the planet's overall temperature trends in more detail than ever before.

These data show, despite the onset of southern summer, most of the planet has gradually cooled over the last two decades. Neptune's global average temperature fell by 8 °C between 2003 and 2018.

Astronomers were immediately surprised to find the dramatic warming of Neptune's south pole over the last two years of their observations, as temperatures rose rapidly by 11 °C between 2018 and 2020.

Neptune's warm polar vortex has been known for years, a polar vortex that is so rapidly warming that it has never been observed before on this planet.

"Our data cover less than half of Neptune's seasons, so no one expected to see large, rapid changes," said co-author Glenn Orton, senior research scientist at Caltech's Jet Propulsion Laboratory (JPL) in the US.

Because Neptune's temperature variations are so unpredictable, astronomers don't yet know what causes it. They suspect this is due to changes in the chemistry of Neptune's stratosphere, or random weather patterns, perhaps even due to the solar cycle.

Further observations will be made over the coming years to explore the reasons for these fluctuations.

Future ground-based telescopes such as ESO's Extremely Large Telescope (ELT) could be used to observe temperature changes like this in greater detail, while NASA, ESA and CSA's James Webb Space Telescope will provide unprecedented new chemical and temperature maps. in Neptune's atmosphere.