Astronomers announced the disappearance of all clouds on Neptune for the first time in three decades, as Neptune is now completely free of clouds.

The scientists observed detailed images of the planet between 1994 and 2022 and discovered a strange pattern that started in 2019. Around the planet's mid-latitudes, it appeared that the cloud cover began to fade, and eventually, all evidence of clouds completely disappeared, according to ProfoundSpace.org.

Imke de Pater, the emeritus professor of astronomy at the University of California, Berkeley said, "I was surprised by how quickly the clouds disappeared on Neptune; we essentially observed a decline in cloud activity within a few months."

The scientists decided to delve deeper to monitor Neptune's appearance, analyzing images from the Keck Observatory captured from 2002 to 2022 and archival observations from the Hubble Space Telescope that began in 1994, along with data from the Lick Observatory in California from 2018 to 2019. They explained that Neptune's clouds are closely related to how the sun behaves during its 11-year activity cycle.

The scientists clarified that the pattern somewhat matches the sun's 11-year activity cycle, albeit with a two-year gap between solar peaks and Neptune's cloud cover. The report stated that it seems when the sun is more active, more clouds begin to form on Neptune, and when it is less active, Neptune's clouds dissipate.

According to NASA, when the weather is stormy on the sun, the more intense ultraviolet rays flood the solar system, and the team found that two years after solar cycle peaks, an increasing number of clouds appear on Neptune.

The scientists stated, "This amazing data gives us the strongest evidence yet that Neptune's cloud cover is linked to the solar cycle; our findings support the theory that ultraviolet sunlight, when strong enough, might lead to a photochemical reaction resulting in Neptune's clouds."

It appears that changes in Neptune's brightness caused by the sun rise and fall relatively in sync with the arrival and movement of clouds on the planet; however, there is a two-year lag between the peak of the solar cycle and the abundance of clouds observed on Neptune, with chemical changes occurring due to photochemistry that happens in Neptune's upper atmosphere and takes time to form clouds.

Carlos Alvarez, an astronomer at the Keck Observatory said, "It is amazing to be able to use ground-based telescopes to study the climate of a world more than 2.5 billion miles away; advances in technology and observation have allowed us to refine models of Neptune's atmosphere, which are essential for understanding the relationship between the ice giant's climate and the solar cycle."