Grilled steak, burnt powder, berries? In search of the secret of the components of the perfume of space

The organizers of the Jean-Luc Melenchon meeting had promised an experiment “immersive” And “aromatic” At the Nantes Exhibition Center (Loire Atlantic). And during the painting dedicated to the space, the audience was already able to detect a slight fragrance mixing the smells of gunpowder, grilled steak, berries and rum. The service provider behind the space perfume remains unknown, but the ring is calling: What are the secrets of the chemical cocktail that can fill the bottle of the universe? NASA certainly had some discussions with a chemist in 2008, but the project never saw the light of day.

Let’s start with the testimonials. Of course, it is impossible to breathe directly into space, but some astronauts nevertheless gave stories based on the smell of the suits, after a spacewalk. The least we can say is that their descriptions are still a long way off. “The smell of space is really different from anything out there.”Dominic Antonelli, Shuttle Discovery pilot. I called by Space.com (in English), described by Thomas Jones, a veteran of NASA “Ozone smell, slight pungent smell” or a “The smell of burning gunpowder” ; Another male finally “Very nice soft metallic feel”.

However, these testimonies present a potential bias, notes Robin Isnard, MD, an astrochemist and Popular Science on the Web. “Some metal surfaces may have been weathered outside the International Space Station, resulting in the production of Some organic matter. This smell reported by astronauts could be a result of oxidation, rather than an intrinsic characteristic of space. This is what happens with certain currencies: in the presence of Minerals and sweat, fatty acids generated by the skin produce certain molecules. It’s what produces that smell that we associate with metal, not coin.

To get answers, it is necessary to identify potential odor molecules in space, thanks to the work of astrochemists. Last month, on the NASA website (in English)In this research on odors, American researcher Luis Almandola raised two distinct playing fields. He cites first next to stars at the end of their lives, which have finished consuming hydrogen. At this point, they then release heavier elements such as carbon, nitrogen, and oxygen. Depending on the distribution of these elements, some stars will produce silica while others will produce soot rich in polycyclic aromatic hydrocarbons (PAHs) – whose smell can make you think of diesel compounds or “With burnt burgers”. Here is the first path near the stars at the end of their lives.

The second path leads to the heart of the “molecular clouds” of the Milky Way, where we “Dust made up of silicate rock core and a blanket of water ice and other compounds (methanol, ammonia, carbon monoxide…) can be found”Robin Isnard explains. In short, we must imagine “Sort of a weird ice cream parlor with a cold drizzle of ice water and a stifling whiff of ammonia.”Jokes Louis Alamandola. Clearly inspired, it also evokes the melancholy smell of a mortuary, due to the possible presence of formaldehyde (formaldehyde). depressed.

How about a space raspberry? A star that emits heat and radiation can be born Activating chemical reactions in this ice Molecular clouds, Robin Isnard continues. Even more complex molecules are produced, with an increased number of atoms: ethanol, aldehydes, and even certain odorous molecules. And therefore , Dust cloud at the center of the Milky Way [nommé Sagittarius B2] It contains large amounts of ethyl formate.Adds another researcher, Scott Sandford, in a NASA article. This compound plays a role in the smell of berries. Moreover, it is the product From a reaction between an acid and a type of alcohol, Than It gives it a rum-like smell..

Be careful, before you fall into the latest “red flaming fruits” collection from space. Flavors are made from a mixture of several molecules, Robin Isnard already remembers. And I’m not sure that ethyl formate alone makes you think of raspberries.” Many other compounds (ketone, ionone, etc.) play an essential role in the flavor of the fruit. On the other hand, “These compounds tend to congregate on the surface [des poussières] It’s not very volatile.”Adds Grégoire Dinger, astrochemist and deputy director of the Institute of Origins at Aix-Marseille University.

Ethyl formate, finally, is only one of dozens of molecules Determined in 2009 (in English) by the Max Planck Institute, during the work done on the Sagittarius B2. In this list, You will definitely find particles that do not smell good! “ He wrote to franceinfo Arnaud Belloche, who co-signed the study. So it’s hard to relate to one of them in particular. More broadly, some 260 molecules identified (in English) in the interstellar medium.

“Knowing the dominant odor does not seem obvious to me because it depends on the composition of the medium, that is, on the proportion of each molecule in the interstellar gas.”

Arnaud Belusch, astrochemist at the Max Planck Institute

in franceinfo

On the other hand, space organic chemistry is still in its infancy. “In fact, there are particles throughout the universe, far more numerous and complex than those identified so far., adds Grégoire Danger. Radio astronomy is simply limited to detectors. After a certain number of atoms, there are twelve”It is difficult to reconstruct these particles of different wavelengths emitted by each type of atom. Thus, the molecular portfolio is undoubtedly more complete than we can imagine today, doubling the possible combinations.

But let’s not go any further, because unfortunately there is still a major hurdle in the search for space fragrance. Even by identifying the molecules of interest, their concentration must be sufficient to be detected by the human organism. Is this the case? “That’s a good question and I don’t have an answer to it.”Answers Arno Beloch. Researcher Uwe Meierhenrich, a specialist in perfume chemistry, explains to franceinfo “The olfactory receptors (which are proteins) will not function at all under these conditions.” So all you have to do is dream and imagine what you want.