Scientists: Planet Uranus smells really bad

Uranus stinks and there’s scientific proof. Researchers confirmed Monday the seventh planet from the sun has an upper atmosphere full of one of the smelliest chemicals known to humans, hydrogen sulfide, according to study published by Nature Astronomy.

The odorous gas is what gives rotten eggs — and human flatulence — their distinctive and unpleasant smell. According to the Environmental Protection Agency, people can smell the gas when it makes up as little as three out of every billion molecules in the air, so imagine what being surrounded by clouds of the stuff would smell like.

“If an unfortunate human were ever to descend through Uranus’ clouds, they would be met with very unpleasant and odoriferous conditions,” Patrick Irwin a physicist at the University of Oxford, who led the study, said in a statement.

Scientists discovered evidence of “the noxious gas swirling high in the giant planet’s cloud tops” after observing how sunlight bounced off Uranus’ atmosphere, according to a news release from the Gemini Observatory, a high-power telescope located on top of Hawaii’s Mauna Kea volcano.

The new findings come after decades of observations and even a visit by the Voyager 2 spacecraft to the blue-green ice giant, the release said. Before making the discovery, scientists had long inferred hydrogen sulfide existed in the planet’s atmosphere, but never “conclusively detected” the gas before, according to Science News.

Using a 26-foot Gemini North telescope, the team of scientists studied the reflected sunlight in infrared and determined what types of molecules made up the planet’s atmosphere, the release said. While evidence of the molecular compounds was “barely there,” Irwin said scientists were still “able to detect them unambiguously” given the sensitivity of their instruments and the “exquisite conditions” on Mauna Kea.

Uranus’ atmospheric composition was so difficult to nail down because when a cloud deck forms by condensation, it hides the gas responsible for forming the clouds beneath levels that can be usually seen with telescopes, Leigh Fletcher, a member of the research team, said in the release.