Scientists: Comet smells like rotten eggs and horse stable

BERN, Switzerland, Oct. 24 (UPI) —

Scientists working with Europe’s Rosetta have gotten the space probe close enough to smell a comet for the first time. Maybe they wish they hadn’t.

Researchers describe the scent coming off 67P/Churyumov-Gerasimenko as reminiscent of rotten eggs and a horse stable.

They had outfitted Rosetta with a sort of artificial nose — an instrument called ROSINA — that can analyze gas vapors and replicate smell. Among other trace chemicals, Chury offers a powerful punch of hydrogen sulfide, ammonia, formaldehyde and hydrogen cyanide.

The strong presence of rotten egg (hydrogen sulfide) and horse stable (ammonia) smells are accented by notes of alcohol (methane) and vinegar (sulfur dioxide). In case that wasn’t gross enough, the hyrdogen cyanide and carbon disulfide offer a hint of sugared almonds.

Researchers say it’s the first time they’ve really gotten a good whiff of a comet.

"We’ve never been that close to a comet," Kathrin Altwegg, the researcher who manages the ROSINA instrument from a lab at the University of Bern in Switzerland, told NPR.

The comet — which Rosetta will soon attempt to anchor to an exploratory craft called Philae — is 250 million miles from the sun. But it’s getting closer. And that’s bad news for astronomers with a weak stomach.

"The closer the comet gets to the sun, the more of its ice will evaporate, and the gas emissions will get more intense," Altwegg explained to Deutsche Welle.