Scientists have now confirmed that Uranus’ atmosphere contains a high amount of hydrogen sulphide. This may not sound dramatic, but hydrogen sulphide is the gas which produces the distinctive smell which comes from flatulence and rotting eggs. 

Patrick Irwin, a planetary physics professor at Oxford University, said “If [a person] could survive the fall down to Uranus, they’d smell a horrible smell of rotten eggs. I’m not sure anyone’s really looked to see what the human nose would do in a hydrogen-helium atmosphere with a bit of hydrogen sulphide, but I imagine that you would still smell this pungent aroma.”

It should be noted that leading astrophysicists did not just carry out this study for shits and giggles. The report, published in Nature Astronomy, shed light on the formation of planets in our solar system

Irwin explained that we now have greater clarity regarding compositional differences between Uranus and Neptune; the ice giants, and Jupiter and Saturn; the gas giants. 

Uranus and Neptune have more hydrogen sulphide in their atmospheres, while Jupiter and Saturn are the opposite. The significance of this, scientists believe, is that it is likely that the ice giants were formed further away from the sun, in a colder region of our solar system. 

“What we think is that for Jupiter and Saturn, where they formed, ammonia was probably mostly in icy form. But hydrogen sulphide was a sort of gas and so less easily absorbed as the planet grew. Whereas for Uranus, and we guess Neptune, they formed farther out where hydrogen sulphide was also in icy form and so could be collected by the planet” elaborated Irwin.