Scent of a Comet: Rotten Eggs and Horse Stable

Scientists using the Rosetta comet orbiter have spent the last several months sniffing the scent of the 67P/Churyumov-Gerasimenko comet, and the results aren't pretty. In fact, they're rather smelly, giving off an odor of rotten eggs and horse stable, according to reports released Thursday.

Despite the unpleasant aroma, which is no Chanel No.5, why are scientists even bothering to smell a comet? Well, such information could actually shed light on the early chemical conditions of our solar system - conditions that would have governed the formation of Earth and subsequent emergence of life, according to NBC News.

Scientists at the University of Bern analyzed the chemicals in the comet's coma, the fuzzy head surrounding its nucleus.

Their findings showed that rotten eggs, horse urine, formaldehyde, bitter almonds, alcohol, vinegar, and a hint of sweet ether make up 67P's potent bouquet, among other things.

"With the odor of rotten eggs (hydrogen sulphide), horse stable (ammonia), and the pungent, suffocating odor of formaldehyde. This is mixed with the faint, bitter, almond-like aroma of hydrogen cyanide. Add some whiff of alcohol (methanol) to this mixture, paired with the vinegar-like aroma of sulphur dioxide and a hint of the sweet aromatic scent of carbon disulphide, and you arrive at the 'perfume' of our comet," Swiss scientist Kathryn Altweg, who lead the comet-sniffing project, said on Rosetta's blog.

For this, the team used a special instrument aboard the European spacecraft Rosetta, which is preparing to drop a lander onto the comet's icy surface Nov. 12. Aside from smell, the orbiter and soon-to-be lander even played doctor, taking 67P's temperature back in mid-July.

Altweg said, via The Associated Press, that the aroma will get even more pungent as 67P gets closer to the Sun, causing it to release more gas and form its characteristic coma trailing behind it.