Gemini Observatory | 2018 Apr 23
Hydrogen sulfide, the gas that gives rotten eggs their distinctive odor, permeates the upper atmosphere of the planet Uranus – as has been long debated, but never definitively proven. Based on sensitive spectroscopic observations with the Gemini North telescope, astronomers uncovered the noxious gas swirling high in the giant planet’s cloud tops. This result resolves a stubborn, long-standing mystery of one of our neighbors in space.
Even after decades of observations, and a visit by the Voyager 2 spacecraft, Uranus held on to one critical secret, the composition of its clouds. Now, one of the key components of the planet’s clouds has finally been verified.
Patrick Irwin from the University of Oxford, UK and global collaborators spectroscopically dissected the infrared light from Uranus captured by the 8-meter Gemini North telescope on Hawaii’s Maunakea. They found hydrogen sulfide, the odiferous gas that most people avoid, in Uranus’s cloud tops.
The Gemini data, obtained with the Near-Infrared Integral Field Spectrometer (NIFS), sampled reflected sunlight from a region immediately above the main visible cloud layer in Uranus’s atmosphere. “While the lines we were trying to detect were just barely there, we were able to detect them unambiguously thanks to the sensitivity of NIFS on Gemini, combined with the exquisite conditions on Maunakea,” said Irwin. “Although we knew these lines would be at the edge of detection, I decided to have a crack at looking for them in the Gemini data we had acquired.” ...
Detection of hydrogen sulfide above the clouds in Uranus’s atmosphere - Patrick G. J. Irwin et al
- Nature Astronomy (online 23 Apr 2018) DOI: 10.1038/s41550-018-0432-1