According to the ESA, the main chemicals being jettisoned by the rock are H232S & 34S. While those chemical names might not conjure any smells in your mind, scientists have hinted that 67P/C-G likely smells of horse manure and rotten eggs.
Yet, as unpleasant as that palate of scents may be, the idea of a comet having a smell is a bit hyperbolic (or should I say hyperbolide).
In the vacuum of space it’s likely that only highly volatile molecules are siphoned off the rock as the Sun's faint rays melt away more unstable ices. That means that if 67P/C-G were given a sniff under Earth-like conditions it might not be as repulsive as the ESA's results dictate.
"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. 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."
While 67P/C-G’s scent isn't likely to be bottled anytime soon its value to researchers is worth more than the frankincense and myrrh of old. With these new results scientists will be able to tease out information about the formation of the solar system's Oort Cloud and Kuiper Belt. What's more, 67P/C-G might help refine our understanding of how the solar system was born.
Image Courtesy of ESA