How does a comet smell? Absolutely awful, at least according to scientists researching the comet 67P/C-G.
The Rosetta space probe is tracking the comet and is scheduled to make a historic landing on its surface next month. One curious finding is that the cosmic body stinks to high heaven.
"The perfume of 67P/C-G is quite strong, with the odor of rotten eggs (hydrogen sulphide), horse stable (ammonia), and the pungent, suffocating odor of formaldehyde," said researcher Kathrin Altwegg, who is charge of the Rosetta's instruments.
As the 2.5 mile-wide comet nears the sun, chemicals within its rock and ice formation begin to vaporize, creating the nasty whiff.