A team of researchers, led by Professor Patrick Irwin from the University of Oxford, has used a simple method developed by amateur astronomer Dr. Steven Hill to determine that Jupiter’s colorful clouds are not made of ammonia ice. The findings, published in the Journal of Geophysical Research: Planets, were made using commercially available telescopes and specially colored filters.
Dr. Hill’s initial results showed that the abundance of ammonia in Jupiter’s atmosphere could be mapped by amateur astronomers, but also revealed that the clouds resided too deeply within the warm atmosphere to be consistent with the conventional view of being composed of ammonia ice. Professor Irwin applied Dr. Hill’s analytical method to observations made with the Multi Unit Spectroscopic Explorer (MUSE) instrument at the European Southern Observatory’s Very Large Telescope in Chile.
Using a computer model, the team found that the primary clouds of Jupiter had to be much deeper than previously thought, in a region of higher pressure and temperature. The resulting clouds are likely composed of ammonium hydrosulfide mixed with photochemical products, which produce the characteristic red and brown colors seen in Jupiter images.
The new method is much faster and simpler than previous analyses, making it easier to verify the results. The team has also applied this method to VLT/MUSE observations of Saturn, finding similar agreement with other studies. The findings suggest that an innovative approach using simple observational techniques can provide valuable insights into the atmosphere of gas giants like Jupiter.
The discovery was triggered by Dr. Hill’s demonstration that amateur astronomers could map ammonia and cloud-top pressure in Jupiter’s atmosphere using commercially available telescopes and filters. This work highlights the potential for citizen scientists to make important contributions to professional research, particularly in areas where innovative methods can provide new insights into complex phenomena.
Source: https://phys.org/news/2025-01-citizen-science-reveals-jupiter-clouds.html