Scientists have determined that the atmosphere above the planet Uranus is full of a gas that makes the distant planet smell like rotten eggs.
科學家們已經確定，天王星上方的大氣層中充滿著一種氣體，使這個遙遠星球聞起來氣味類似臭雞蛋。
A new study, published in the journal Nature Astronomy, established the chemical composition of Uranus' upper cloud deck for the first time.
發表在《自然-天文學》雜誌上的一項新研究，首次確定了天王星的高空雲的化學成分。
Using an instrument called the Near-Infrared Integral Field Spectrometer (NIFS) at the Gemini North telescope in Hawaii, researchers determined that Uranus' cloud cover is composed of hydrogen sulfide (H2S) gas, which is what gives rotten eggs their distinctive, noxious scent.
研究人員藉助了位於夏威夷、搭載了一種稱為近紅外積分場光譜儀的儀器的北雙子座望遠鏡，確定了天王星的雲層是由硫化氫氣體組成的，而這種氣體具備臭雞蛋獨特的有毒氣味。
Hydrogen sulfide is a "colorless, flammable, extremely hazardous gas with a 'rotten egg' smell," according to the Occupational Health And Safety Administration.
據職業健康與安全管理局介紹，硫化氫是一種「無色、易燃、極具毒性、有臭雞蛋味的氣體」。
Scientists had speculated that Uranus and Neptune's clouds could also exhibit ammonia ice, as on gas giants Jupiter and Saturn, but previous observations from both ground telescopes and the Voyager 2 spacecraft were inconclusive.
科學家們推測，天王星和海王星的雲層也可能表現出氨冰，就像木星和土星一樣，但地面望遠鏡和旅行者2號太空飛行器的觀測結果是不確定的.
The new study revealed atmospheric differences between the gas and ice giants that could answer questions about the planets' early history, scientists said.
科學家們表示，這項新研究揭示了氣體和冰巨星之間的大氣差異，可以回答有關行星早期歷史的問題。