spaceSpace and Physics

Comet 67P Smells Like Cat Pee, Almonds, And Rotten Eggs


Robin Andrews

Science & Policy Writer

67P, as snapped by Rosetta. ESA

Comet 67P/Churyumov-Gerasimenko has provided the scientific world with a host of remarkable discoveries, including a plethora of some of the most remarkable examples of astrophotography the world has ever seen. Scientists never stop asking questions, though, and their curious minds have turned to a more peculiar aspect of the distant chunk of ice and rock: its smell.

As reported by New Scientist, the Philae lander has been analyzing the strange chemistry of the alien, duck-shaped, spacefaring object for some time now, and although a geological sample won’t ever make it back to planet Earth, artificial samples are being created on Earth in order for scientists to have a bit of a poke around.


Somewhat bizarrely, a so-called “perfume” has been created in order to mimic the aroma of 67/P. Thanks to a collaboration from the Rosetta team, the Open University and The Aroma Company, any member of the public can take their turn having a sniff if they turn up to the Royal Society summer exhibition in London this July. Don’t expect the scents of roses or sugar, however – apparently, it smells like rotten eggs, cat urine, and extremely bitter almonds.

Curiously, the comet’s composition is mainly water vapor, carbon dioxide and carbon monoxide, none of which actually have a smell that humans can detect. However, Philae has picked up on the presence of ammonia (a component of, among other things, cat urine), hydrogen sulfide (a chemical found in rotting eggs), and hydrogen cyanide (something that can effuse from almonds).

These are actually harmful compounds to inhale in large volumes; fortunately, the artificial 67P scent here on Earth contains non-toxic chemicals that realistically simulate this smell without actually poisoning those having a daring whiff of it.

According to some, the smell, although rather pungent, actually contains some floral notes too – but it’s doubtful that anyone will ever come to enjoy the scent. It’s actually a huge relief, then, that we live on a planet where petrichor – the smell of damp soil after the rain – dominates our lives far more than any of these noxious smells tend to.


If you can’t make it to the exhibition next month to find out what 67P smells like, then there is one possible alternative: Crush up some extremely old almonds in your hands as you stand above an active volcanic vent that a cat has just urinated in. It’s the closest you may ever get to experiencing the glorious smells of outer space.

[H/T: New Scientist]


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