Neptune is a much paler shade of blue than we thought

A new study has revealed the true colour of the planet Neptune - and it's a lot paler than we all thought.

Neptune's true colour is a pale shade of greenish-blue that's very similar to its neighbouring planet Uranus.

Professor Patrick Irwin and his team at the University of Oxford's Department of Physics studied images of the planet to get a truer understanding of its colour.

They found that both planets are a similar shade of greenish blue, despite the commonly-held belief that Neptune is a deep azure and Uranus has a pale cyan appearance.

How did the misunderstanding about Neptune's colour happen?

What we believed about Neptune's colour was based on pictures from the 1980s, when Nasa's Voyager 2 spacecraft flew to the furthest planets and sent back photographs.

In order to be able to show the fine details of the image, Nasa adjusted the photos - similarly to the way we might use filters today.

When the pictures were released, they included a caption to explain that they were "enhanced", but over time as the the pictures were being used without this explanation, people began to believe that the deep blue shown was Neptune's true colour.

Now Professor Patrick Irwin and his team at the University of Oxford team have reprocessed the original pictures, along with newer images from the Hubble telescope, to show how the human eye might see the planets.

"The true-colour image is much more boring and bland because of the way the eye works," says Professor Irwin.