Although it has been summer for 'just' 17 years, temperatures in the southern hemisphere of Neptune have had unexpected rapid variations, with peaks of cold and heat alternating like roller coasters and with differences of tens of degrees.
The phenomenon, of which astronomers are trying to understand the causes, is described in the journal Planetary Science.
The discovery is from the British University of Leicester and is based on data from several observatories, including the Very Large Telescope (Vlt) of the Southern European Observatory (ESO).
Just like the Earth, Neptune experiences the changing of the seasons along its orbit around the Sun.
The difference is that the gigantic gas planet is about 30 times more distant from the Sun than the Earth and that one year of it, that is the time to complete one revolution around the Sun, is equivalent to 165 Earth years.
Using infrared sensors, capable of measuring the amount of heat emitted by the outer layers of the atmosphere, researchers have been monitoring the temperature variations of the planets from the Solar System for years, but Neptune is a real enigma.
Although the southern Neptunian hemisphere entered in the summer starting in 2005, the data indicate that between 2003 and 2018 temperatures would have dropped by about 8 degrees while from 2018 they have rapidly shot upwards with a +11 degrees in a few months.
Rapid and unexpected oscillations whose causes scientists are unable to decipher at the moment, but which could perhaps be clarified with the entry into service of the James Webb space telescope, expected in the coming weeks.
