Rapid changes in Neptune's temp observed
Neptune, a very cold planet with average temperature reaching around minus 220 degrees Celsius, has seen rapid and unexpected temperature variations in the last two decades, scientists have found.
image for illustrative purpose
London: Neptune, a very cold planet with average temperature reaching around minus 220 degrees Celsius, has seen rapid and unexpected temperature variations in the last two decades, scientists have found.
Using ground-based telescopes, including the European Southern Observatory's Very Large Telescope (ESO's VLT), an international team of astronomers tracked Neptune's atmospheric temperatures over a 17-year period.
They found a surprising drop in Neptune's global temperatures followed by a dramatic warming at its south pole.
"This change was unexpected," said Michael Roman, a postdoctoral research associate at the University of Leicester, UK. "Since we have been observing Neptune during its early southern summer, we expected temperatures to be slowly growing warmer, not colder," he added.
Like Earth, Neptune experiences seasons as it orbits the Sun. However, a Neptune season lasts around 40 years, with one Neptune year lasting 165 Earth years. It has been summer in Neptune's southern hemisphere since 2005.
Despite the onset of southern summer, the data published in The Planetary Science Journal, showed that most of the planet had gradually cooled over the last two decades. The globally averaged temperature of Neptune dropped by 8 degrees Celsius between 2003 and 2018.
The astronomers were also surprised to discover a dramatic warming of Neptune's south pole during the last two years of their observations, when temperatures rapidly rose 11 degrees Celsius between 2018 and 2020.
Although Neptune's warm polar vortex has been known for many years, such rapid polar warming has never been previously observed on the planet.
