Astronomers have been grappling with an enigma surrounding Neptune, and it seems they may have now unraveled its mystery.

The ghostly, cirrus-like clouds that once adorned the ice giant significantly receded around four years ago, leaving only a solitary patch hovering above its southern pole, CNN reported.

Drawing from nearly three decades of observations of Neptune captured by three different space telescopes, researchers have deduced that the ice giant’s diminished cloud cover might be connected to fluctuations in their prevalence that align with the solar cycle.

This revelation stems from a recent study published in the journal Icarus.

Throughout the solar cycle, the activity within the sun’s dynamic magnetic fields undergoes periodic waxing and waning.

NASA explains that the magnetic field experiences a flip every 11 years, becoming more intricate akin to a tangle of yarn.

During heightened solar activity, the solar system is bombarded with intensified ultraviolet radiation.

Leveraging data from NASA’s Hubble Space Telescope, the W.M. Keck Observatory in Hawaii, and the Lick Observatory in California, researchers observed 2.5 cycles of cloud behavior spanning a 29-year period of Neptune observations.

During this time, the planet’s reflectivity surged in 2002 and then faded in 2007. Subsequently, Neptune brightened again in 2015 before experiencing a dimming in 2020, reaching the lowest visibility ever recorded.

This was when a significant portion of its cloud cover dissipated.

Written by staff