New images reveal Neptune’s REAL colour after scientists spent decades grappling with the ‘blue hue’ mystery

NEW images of Neptune have revealed its true colour after scientists spent decades grappling with the ‘blue hue’ mystery.

Fresh analysis of images of Neptune has revealed that it is a nearly identical shade of blue to neighbouring Uranus, according to a new Oxford University study.

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Astronomers have long known that most modern images of the two planets do not accurately reflect their true colours[/caption]

The first pictures of Neptune were beamed back to Earth in 1989 via Nasa’s Voyager 2 spacecraft.

The images revealed a deep blue orb, which sat in contrast to its much paler planetary neighbour Uranus.

The planetary ‘twins’ have a lot in common – they have similar masses, sizes, and atmospheric compositions – but seemingly did not share the same blue hue.

The difference has puzzled scientists for more than 30 years.

Now, a new study, led by Professor Patrick Irwin of Oxford University and published in the Monthly Notices of the Royal Astronomical Society today, has revealed the pair share a pale greenish blue.

Irwin says the findings are Neptune’s “most accurate representation yet”.

Astronomers have long known that most modern images of the two planets do not accurately reflect their true colours.

The single-colour images of Neptune from Voyager 2 were later recombined to create composite colour images, which were not wholly accurate.

“Although the familiar Voyager 2 images of Uranus were published in a form closer to ‘true’ colour, those of Neptune were, in fact, stretched and enhanced, and therefore made artificially too blue,” Irwin explained.

“Even though the artificially-saturated colour was known at the time amongst planetary scientists – and the images were released with captions explaining it – that distinction had become lost over time.

“Applying our model to the original data, we have been able to reconstitute the most accurate representation yet of the colour of both Neptune and Uranus.”

In the new study, the researchers used data from Hubble Space Telescope’s Space Telescope Imaging Spectrograph (STIS) and the Multi Unit Spectroscopic Explorer (MUSE) on the European Southern Observatory’s Very Large Telescope.

Researchers used this data to re-balance the composite colour images recorded by the Voyager 2 camera, and also by the Hubble Space Telescope’s Wide Field Camera 3 (WFC3), to come up with a more accurate representation.