Irwin says scientists have long suspected Uranus was home to hydrogen sulphide, but were unable to confirm it. The birth of the ice giantsBut beyond confirming that Uranus smells bad, the study also helps scientists better understand how and where planets formed in our solar system. Uranus — and presumably its neighbour Neptune, Irwin says — have more hydrogen sulphide than ammonia, while Jupiter and Saturn are the opposite. But hydrogen sulphide was a sort of gas and so less easily absorbed as the planet grew," he said. Hydrogen sulphide in large quantifies is extremely poisonous.

Source: CBC News April 24, 2018 20:37 UTC