The iconic images of Uranus and Neptune, acquired by NASA’s Voyager 2 probe, do not faithfully render the colors of these two gaseous planets. Over time, NASA’s explanations regarding these colors were gradually forgotten, misleading as to the true reality of the hues. A team of scientists, led by Professor Patrick Irwin of the University of Oxford, has managed to put together the most accurate representation yet of the color of Neptune and Uranus. Amazing!
This will interest you too
[EN VIDÉO] Journey among the giant planets of the Solar System The Voyager missions, launched in the 1970s, gave humanity the first visions…
While astronomers have long known that the most modern images of Neptune Neptune and Uranus Uranus do not faithfully represent their true colors, the spectacular and famous images acquired by Voyager 2Voyager 2 of these two planets have led us to believe, erroneously, that Neptune is a deep blue and Uranus has a pale blue-green appearance.
In a study published in Monthly notices of the Royal Astronomical Society, Professor Patrick Irwin of the University of Oxford and his team reveal that the two planets are actually much more similar in color than is commonly thought. In fact, these two planets have a similar shade of greenish blue, with Neptune showing just a hint of extra blue due to a thin layer of haze.
The combined use of Hubble and VLT shows us the true colors of these two planets
This misconception originates in the fact that images acquired of the two planets throughout the 20th century – particularly by NASA’s Voyager 2 mission, the only probe to have flown by these worlds – recorded images with distinct colors. The monochrome images were then combined to create composite color images, which were not always perfectly balanced to achieve an accurate representation of actual colors. Especially in the case of Neptune, these images were often artificially enhanced with a “too blue” tint. Furthermore, the first images of Neptune taken by Voyager 2 had significantly improved contrast to better reveal clouds, bands and winds, thus influencing our current perception of the planet. As Professor Irwin points out, “ Although the familiar images of Uranus taken by Voyager 2 were released with more accurate colors, those of Neptune were stretched and enhanced, making them artificially too blue ».
Neptune and Uranus: Hubble reveals the secret of their colors
Uranus’ seasonal color change explained
To reconstruct the most accurate color yet of Neptune and Uranus, the researcher and his team used HubbleHubble’s STIS imaging spectrograph and the Muse spectrograph on ESO’s VLT. They also solved the mystery of Uranus’ seasonal color change during its 84-year orbit around the Sun. They attribute this to the planet’s unusual rotation, with the poles nearly facing the Sun during solstices, causing variations in the regions’ reflectivity polar. This is important, according to the authors, because any change in the reflectivity of the polar regions would then have a significant impact on the overall brightness of Uranus as seen from our Planet.
Professor Irwin highlighted that this study is the first to combine a quantitative model with imaging data to explain Uranus’ color changes during its orbit. Dr. Heidi Hammel of the Association of Universities for Astronomical Research (Aura), who has spent decades studying Neptune and Uranus but was not involved in the study, believes that ” this in-depth study will finally put an end to the misperception of Neptune’s color and the unusual changes in the color of Uranus, which have persisted for decades ».
2024-01-05 09:59:05
#true #colors #Uranus #Neptune #revealed
