What does a comet smell like?

"It stinks," says Kathrin Altwegg, a researcher at the University of Bern in Switzerland who runs an instrument called ROSINA that picked up the odor.
 The European Space Agency has posted a full rundown of the comet's BO on its website. The mix includes ammonia (NH3), hydrogen sulphide (H2S) and formaldehyde (CH2O). Of course, anyone visiting the comet would be wearing a spacesuit (on top of that, the sense of smell is notoriously numb in space). Nevertheless, taking a whiff of this comet would be like sharing a horse barn with a drunk and a dozen rotten eggs.  continue