Recent findings have challenged the traditional understanding of Jupiter‘s clouds, showing they are not primarily composed of ammonia ice. Instead, it has been discovered that the clouds are formed from ammonium hydrosulfide mixed with photochemical materials. This revelation, achieved through a collaboration of professional and amateur astronomers, sheds new light on the composition and dynamics of Jupiter’s atmosphere, offering simpler methods for mapping the planet’s cloud layers.

Ammonium Hydrosulfide Identified as Main Cloud Component

According to the study published in the Journal of Geophysical Research: Planets, the breakthrough came after amateur astronomer Dr. Steven Hill developed a method using commercial telescopes and specific filters to measure ammonia abundance and cloud-top pressures. His technique demonstrated that the clouds reside in warmer regions of Jupiter’s atmosphere, deeper than the expected ammonia cloud layer. This conclusion was confirmed when the method was applied to data from the Multi Unit Spectroscopic Explorer (MUSE) instrument on the Very Large Telescope in Chile.

Professor Patrick Irwin of the University of Oxford explained to phys.org that the simulations showed light interacting with gases at higher pressures and temperatures. This ruled out ammonia ice as the main component of the clouds and instead pointed to ammonium hydrosulfide mixed with smog-like materials. These substances are believed to contribute to the planet’s characteristic red and brown hues.

New Opportunities for Citizen Science

The study highlights how Dr. Hill’s method, which compares brightness levels in narrow color filters, matched the accuracy of complex computational techniques. According to a statement made to phys.org by John Rogers of the British Astronomical Association, this simpler method allows amateurs to frequently monitor variations in Jupiter’s atmospheric features, linking chemical changes to observable weather phenomena like storms and the Great Red Spot.

Photochemical reactions in Jupiter’s atmosphere are thought to prevent ammonia from condensing into clouds. Similar observations were made on Saturn, suggesting that photochemical processes play a significant role in shaping the atmospheres of gas giants.