THE clouds on Neptune have almost completely disappeared for the first time in about three decades helping researchers better understand its overall climate.
Neptune was first recognized to have a healthy amount of clouds scattered across the planet, but images over the past several years show that they have seemed to slowly vanish.
Getty – ContributorImage of Neptune once showed heavy cloud coverage which have slowly disappeared over time[/caption]
Imke de Pater, Erandi Chavez, Erin Redwing (UC Berkeley)/W. M. Keck ObservatoryThe clouds increasingly disappeared each year that Neptune was photographed[/caption]
The images were captured from 1994 to 2022 from Maunakea, Hawaii through the W. M. Keck Observatory and from space via NASA’s Hubble Space Telescope.
Each year Neptune’s cloud coverage became less and less – then a photo from 2020 shows the planet almost completely cloudless, per an analysis reported by the W. M. Keck Observatory.
Researchers have studied the images since they were first taken in 1994 to get a better understanding of Neptune’s climate and have now come up with enough information to make an estimation.
“Even four years later, the images we took this past June showed the clouds haven’t returned to their former levels,” said Erandi Chavez, a graduate student at Harvard University’s Center for Astrophysics who led the study when she was an undergraduate astronomy student at UC Berkeley, per the report.
“This is extremely exciting and unexpected, especially since Neptune’s previous period of low cloud activity was not nearly as dramatic and prolonged.”
It is believed that this is driven by a process that we don’t fully understand – proving it has a complicated and dynamic atmosphere.
But it has led the team of researchers to believe that Neptune’s cloud coverage must have some correlation with an 11-year solar cycle with the sun.
This is shocking and unexpected because Neptune is the farthest from the sun at about 4.5 billion miles away.
The correlation belief is due to the Sun’s magnetic field reversing every 11 years which comes with an increase in UV irradiation followed by a “quiet period.”
The researchers found that clouds start to appear on Neptune around 2 years after the powerful UV irradiation ends.
The last cycle occurred in 2015, then darkened in 2020 to the lowest level ever observed.
“These remarkable data give us the strongest evidence yet that Neptune’s cloud cover correlates with the Sun’s cycle,” said Imke de Pater, emeritus professor of astronomy at UC Berkeley and senior author of the study, per the report.
“Our findings support the theory that the Sun’s UV rays, when strong enough, may be triggering a photochemical reaction that produces Neptune’s clouds.”
The new discovery allows researchers to grasp a better understanding of Neptune’s overall climate.
Considering Neptune is billions of miles away, this is a major milestone for researchers.
“It’s fascinating to be able to use telescopes on Earth to study the climate of a world more than 2.5 billion miles away from us,” said Carlos Alvarez, staff astronomer at Keck Observatory and co-author of the study, per the report.
“Advances in technology, as well as our Twilight Observing Program, have enabled us to constrain Neptune’s atmospheric models, which are key to understanding the correlation between the ice giant’s climate and the solar cycle.”
Imke de Pater, Erandi Chavez, Erin Redwing (UC Berkeley)/W. M. Keck ObservatoryThe most recent photo of Neptune show it with almost no clouds[/caption]