All of Neptune’s clouds have disappeared, astronomers announced this unexpected update on Thursday, August 17. For the first time in three decades, Neptune is almost completely cloud-free.
Scientists observed detailed images of the planet between the years 1994 and 2022, they noticed a strange pattern beginning in 2019. Around the planet’s mid-latitudes, cloud coverage seemed to start fading. Eventually, all evidence of clouds totally vanished, Space.com reported.
Since 2019, scientists saw only one patch of wispy white drifting around the planet’s south pole.
“I was surprised by how quickly clouds disappeared on Neptune,” Imke de Pater, an emeritus professor of astronomy at the University of California, Berkeley and senior author of a study on the findings, said in a statement. “We essentially saw cloud activity drop within a few months.”
The scientists decided to dig deeper. To monitor the evolution of Neptune’s appearance, Chavez and her team analyzed Keck Observatory images taken from 2002 to 2022, the Hubble Space Telescope archival observations beginning in 1994, and data from the Lick Observatory in California from 2018 to 2019. They explained that Neptune’s clouds are inextricably linked with the way our sun behaves during its 11-year-long activity cycle.
The scientist said that the pattern somewhat matches up with the sun’s 11-year cycle of activity, albeit with a two-year lag between the sun’s extremes and Neptune’s. It seems that when the sun is most active, more clouds begin to form on Neptune, and when it is least active, Neptune’s clouds dissipate, a New Scientist report said.
According to NASA‘s release, when it’s stormy weather on the Sun, more intense ultraviolet (UV) radiation floods the solar system. The team found that two years after the solar cycle’s peak, an increasing number of clouds appear on Neptune.