Changes in Neptune’s heat-infrared brightness, measurement of temperature in Neptune’s atmosphere. The plot shows the time-related change in all images taken by underground telescopes in the heat-infrared brightness from Neptune’s stratosphere. Bright pictures are interpreted as hot. Thermo-infrared images (above) at wavelengths of ~ 12 µm (above) show the appearance of Neptune in 2006 (2009 observed by the VISIR instrument of the European Southern Observatory’s largest telescope), and 2020 (observed by the SubarSCOM instrument). The South Pole seems to have warmed dramatically over the past few years. Credit: Michael Roman / NASA / JPL / Voyager-ISS / Justin Cowart
Neptune is colder than we thought
New research led by astronauts at the University of Leicester has revealed what the temperature is like
Neptune seen in 2020 in visible light (center) and heat-infrared wavelengths (right). The center image combines multiple images from the Hubble Space Telescope, while the heat-infrared image on the right was taken from the Subaru telescope in Maunakeya. , Hawaii. In heat-infrared, Neptune’s hot south pole glows brighter than ever before. Credit: Michael Roman / NASA / ESA / STSci / MH Wong / LA Sromovsky / PM Fry
By analyzing the data, researchers were able to reveal a more complete picture of Neptune’s temperature trends than ever before.
But to the astonishment of researchers, these composite data show a decline in Neptune’s thermal brightness since the onset of reliable thermal imaging in 2003, which indicates that the global average temperature in Neptune’s galaxy – the layer of the atmosphere just above its active atmospheric layer – has decreased. Approximately 8 degrees
View of Voyager 2 Neptune, captured in August 1989. Credit: NASA / JPL-Caltech / Kevin M. Gill