Uranus is a place totally inhospitable to life, but even if we could live there, we would not want to thanks to the awful stench we would find. That is because a new study has revealed that the upper atmosphere of the planet is composed of hydrogen sulfide, which would smell to us like rotten eggs a thousand times over.

Of course, mankind would encounter a lot more problems than that if they ever visited Uranus, as the temperature reaches negative 200 degrees Celsius and the atmosphere is composed of methane, helium, and hydrogen that would suffocate us would we ever atttempt to breathe it in.

The discovery is fascinating because it tells us a lot more about the composition of the clouds that float high up in the Uranus sky. Scientists have been trying to figure out if they have ammonia ice like Jupiter and Saturn do, or if it sjust hydrogen sulfide ice. Studies so far have been inconclusive, and the planet’s great distance makes it hard to study in more detail.

Researchers use the Near-Infrared Integral Field Spectrometer (NIFC) on the 26-foot Gemini North telescope in Hawaii to study Uranus and its atmosphere.

“This work is a strikingly innovative use of an instrument originally designed to study the explosive environments around huge black holes at the centers of distant galaxies,” said Chris Davis of the United State’s National Science Foundation, a leading funder of the Gemini telescope. “To use NIFS to solve a longstanding mystery in our own Solar System is a powerful extension of its use.” Davis adds.