Why do comets smell so bad?

A European Space Agency probe has detected new molecules in the fumes of comet 67P/C-G, and their cumulative odor not exactly pleasant.

ESA/AP/File
In this Aug. 3, 2014 file photo taken by Rosetta’s OSIRIS narrow-angle camera, Comet 67P/Churyumov-Gerasimenko is pictured from a distance of 285 kms. Scientists at the European Space Agency on Monday, Sept. 15, 2014, announced the spot where they will attempt the first landing on a comet hurtling through space at 55,000 kph (34,000 mph). The maneuver is one of the key moments in the decade-long mission to examine the comet and learn more about the origins and evolution of objects in the universe.

A robotic space probe has been catching whiffs of a comet, and it is apparently rather malodorous.

Tucked aboard the European Space Agency's Rosetta spacecraft, which is currently preparing to drop a lander on Comet 67P/Churyumov–Gerasimenko, some 250 million miles from the sun, is the Rosetta Orbiter Sensor for Ion and Neutral Analysis. ROSINA, as the spacecraft's "nose" is called, has picked up on some new molecules in 67P/C-G which suggest that, as the European Space Agency put it: "If you could smell the comet, you would probably wish that you hadn't."

Rosetta, which has been sniffing the fumes of the comet since early August with its two mass spectrometers recently detected formaldehyde (CH2O), hydrogen sulphide (H2S), hydrogen cyanide (HCN), sulphur dioxide (SO2), carbon disulphide (CS2). These grow the list of previously detected water (H2O), carbon monoxide (CO), carbon dioxide (CO2), ammonia (NH3), methane (CH4), methanol (CH3OH).

In an ESA press release, Kathrin Altwegg, a lead scientist on the project, explained, "The perfume of 67P/C-G is quite strong, with the odour of rotten eggs (hydrogen sulphide), horse stable (ammonia), and the pungent, suffocating odour 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."

But sniffs aside, the detailed analysis of the noxious mixture, and how it varies as 67P/C-G grows more active, will allow scientists to determine the comet's makeup, according to the European Space Agency. Researchers can then compare 67P/C-G with other comets, such as those originating from the Kuiper Belt, and those hailing from the distant Oort cloud (like Comet Siding Spring, which recently flew past Mars).

"The goal is to gain insights into the fundamental chemical makeup of the solar nebula from which our solar system and, ultimately, life itself emerged," according to the European Space Agency.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.