{"id":48737,"date":"2023-08-19T07:38:00","date_gmt":"2023-08-19T07:38:00","guid":{"rendered":"http:\/\/a7df1831-9ebb-43b5-b928-46067ac0df4e"},"modified":"2023-08-24T19:33:46","modified_gmt":"2023-08-24T19:33:46","slug":"activity-on-the-sun-is-responsible-for-neptunes-clouds-disappearing-say-astronomers","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/activity-on-the-sun-is-responsible-for-neptunes-clouds-disappearing-say-astronomers\/","title":{"rendered":"Activity on the Sun is responsible for Neptune’s clouds disappearing, say astronomers"},"content":{"rendered":"

The 11-year solar cycle of our Sun is responsible for Neptune\u2019s clouds disappearing, according to a new study. <\/p>

By Iain Todd\n <\/p>

Published: Saturday, 19 August 2023 at 07:38 AM<\/p>

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Activity on the Sun is responsible for Neptune’s clouds disappearing, say astronomers<\/h1>

The 11-year solar cycle of our Sun is responsible for Neptune\u2019s clouds disappearing, according to a new study made using the Hubble Space Telescope<\/a>.<\/p>

Neptune<\/a> is the most distant planet from the Sun, and its orbit is so huge that its seasons each last about 40 years.<\/p>

But seasonal changes aren\u2019t what\u2019s driving changes in Neptune\u2019s cloudy weather: it\u2019s the rhythmic activity of our Sun.<\/p>\n

Cloud systems seen in Neptune’s southern hemisphere, photographed by the Voyager 2 spacecraft. Credit: NASA<\/figcaption><\/figure>\n

This is despite the fact that Neptune is so far away and receives just 0.1% of sunlight intensity compared with Earth.<\/p>

Our Sun is more active at times than others, with dynamic surface features like sunspots and solar prominences following peaks and troughs over a period of about 11 years.<\/p>

This is known as the solar cycle<\/a>, and the disappearance of Neptune’s clouds seems to be linked to that very solar cycle.<\/p>

The Sun is currently going through Solar Cycle 25<\/a>.<\/p>\n

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A sequence of Hubble Space Telescope images showing changes in Neptune cloud cover, which seems to correlate to changes in the solar cycle. Credits: NASA, ESA, Erandi Chavez (UC Berkeley), Imke de Pater (UC Berkeley)<\/figcaption><\/figure>\n

What the Neptune solar cycle study found<\/strong><\/h2>

A team of astronomers led by the University of California (UC) Berkeley<\/a> studied Neptune and found that an abundance of clouds usually observed at mid-latitudes began to fade in 2019.<\/p>

The findings have been published in the journal Icarus<\/a>.<\/p>

“I was surprised by how quickly clouds disappeared on Neptune,” says Imke de Pater, emeritus professor of astronomy at UC Berkeley and senior author of the study.<\/p>

“We essentially saw cloud activity drop within a few months.”<\/p>

“Even now, four years later, the most recent images we took this past June still show the clouds haven’t returned to their former levels,” says Erandi Chavez, a graduate student at the Harvard-Smithsonian Center for Astrophysics<\/a>, who led the study.<\/p>

“This is extremely exciting and unexpected, especially since Neptune’s previous period of low cloud activity was not nearly as dramatic and prolonged.”<\/p>\n

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Solar activity over cycles 22-24\nCredit: David Hathaway, NASA, Marshall Space Flight Center<\/figcaption><\/figure>\n

Chavez and the team used a wealth of data from some of humanity’s greatest telescopes to carry out the study.<\/p>

Data included Keck Observatory images taken from 2002 to 2022, Hubble Space Telescope observations beginning in 1994 and data from the Lick Observatory in California from 2018 to 2019.<\/p>

This allowed the team to record the evolution of Neptune’s atmospheric appearance over time.<\/p>

Data shows an apparent pattern between seasonal changes in Neptune\u2019s cloud cover and the solar cycle.<\/p>

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