When it comes to planets with large spots, Jupiter and its famous Great Red Spot may come to mind.

But a study has shed new light on a big, lesser-known place in our solar system.

Using the European Space Agency’s Very Large Telescope (VLT), scientists have observed a large dark spot on Neptune measuring around 6,200 miles (10,000 km) in diameter, 20 times the size of the Grand Canyon.

This great void has an unexpected smaller bright spot next to it, and scientists still aren’t sure how it formed.

Speaking to MailOnline, Professor Patrick Irwin, a professor at the University of Oxford and lead researcher on the study, said: “We know that these dark spots are anticyclonic vortices, just like the Great Red Spot on Jupiter, but it is not known how or why are they formed? clearly understood.’

Neptune’s dark spot was first observed by NASA’s Voyager 2 spacecraft in 1989.

However, it is not a permanent feature and goes away every few years. which makes observing it in sufficient detail difficult.

In 2018, NASA’s Hubble Space Telescope detected the dark spot again.

“The Hubble Space Telescope has seen several dark spots since the Voyager 2 GDS,” said Professor Irwin.

“These spots appear to form randomly every few years in mid-northern or southern latitudes and then drift toward the equator, finally disappearing after about an Earth year.”

In this new study, Professor Irwin and his team set to work studying the dark spot from the ground for the first time.

The VLT is equipped with a multi-unit spectroscopic explorer, which splits sunlight reflected from Neptune into its component colors and wavelengths.

This allowed the team to study the site in more detail than ever before.

“I am absolutely thrilled to have been able to not only detect a dark spot from the ground for the first time, but also record a reflection spectrum of such a feature for the first time,” said Professor Irwin.

Different wavelengths explore different depths in Neptune’s atmosphere, meaning the spectrum can infer the size and height of the dark spot, as well as its chemical composition.

The new observations rule out the possibility that the dark spots are caused by a “clearing” of the clouds.

The VLT is equipped with a multi-unit spectroscopic scanner, which splits sunlight reflected from Neptune into its component colors and wavelengths.

Instead, the researchers believe that the dark spots are likely the result of ice and haze mixing in the atmosphere, causing air particles to darken.

The observations also yielded a surprising result.

“In the process we discovered a rare type of deep, bright cloud that has never been identified before, even from space,” said study co-author Dr. Michael Wong from the University of California, Berkeley.

According to the researchers, these rare clouds explain the appearance of a bright spot next to a larger dark spot.

The team hopes the findings demonstrate the capabilities of ground-based telescopes.

“This is a staggering increase in humanity’s ability to observe the cosmos,” added Dr Wong.

“At first, we could only detect these points by sending a spacecraft there, like Voyager. Then we got the ability to tell them apart remotely with Hubble.

‘Finally, technology has advanced to allow this from the ground. This could put me out of a job as a Hubble observer!’

WHAT IS THE GREAT RED SPOT OF JUPITER?

Jupiter’s Great Red Spot is a giant oval of crimson clouds in Jupiter’s southern hemisphere that run counterclockwise around the oval’s perimeter.

The largest storm in the solar system, it appears as a deep red sphere surrounded by layers of pale yellow, orange and white.

Caught between two jet streams, the Great Red Spot is an anticyclone that rotates around a center of high atmospheric pressure that spins it in the opposite direction to hurricanes on Earth.

Jupiter’s Great Red Spot is a giant oval of crimson clouds in Jupiter’s southern hemisphere that run counterclockwise around the oval’s perimeter.

Winds within the storm have been measured at several hundred miles per hour, with storm winds greater than any storm on Earth, NASA astronomers said.

At the end of the 19th century it was estimated to be about 56,000 kilometers (35,000 miles) in diameter, wide enough to fit four Earths side by side.

Measuring 16,000 kilometers (10,000 miles) across as of April 3, 2017, the Great Red Spot is 1.3 times wider than Earth and is gradually shrinking over time.