Something stinks in the far reaches of our solar system.
A study published in the journal Nature Astronomy on Monday suggests that the clouds that form the upper atmosphere of Uranus are largely composed of hydrogen sulfide gas — the same compound found in rotting eggs that produces their signature odor.
Scientists have speculated about whether Uranus' clouds contained hydrogen sulfide or ammonia, which is found in Jupiter's and Saturn's atmospheres, Space reported. But until now, there has been no concrete proof; Jupiter and Saturn, meanwhile, are much closer to Earth, and thus much easier to observe. The "lucky break" that allowed researchers to finally observe the miniscule gas particles in Uranus' atmosphere was the Gemini telescope in Hawaii, said Leigh Fletcher, one of the co-authors of the study.
Based on what they've discovered about Uranus, scientists now theorize that Neptune's atmosphere may contain hydrogen sulfide as well — which may make humans reluctant visitors to the far-off planets. But Patrick Irwin, the study's lead author, says the rotten egg smell would be the least of anyone's concerns: "Suffocation and exposure in the atmosphere" would be a much bigger problem to worry about, he quipped.
Read more about the study at Space.