This story is over 5 years old.

That Comet We Just Landed On Smells Like Ass

Earlier today we landed a fucking spacecraft on a comet. The internet is freaking out about it, sharing dark images from outer-space. What you can't tell from the photos, however, is that the comet '67P/Churyumov-Gerasimenko' smells worse than death.

Earlier today we landed a fucking spacecraft on a comet. The internet is freaking out about it, sharing dark, blurry images from outer-space at roughly the speed of light. What you can't tell from the photos, however, is that the comet, known as 67P/Churyumov-Gerasimenko, smells worse than the inside of an asshole. Using data collected from the Rosetta Orbiter Sensor for Ion and Neutral Analysis (ROSINA), a recent University of Bern study showed that comets smell like a combination of rotten eggs (hydrogen sulphide), horse stable (ammonia), along with alcohol, formaldehyde, almond, and vinegar.


It's remarkable, when you think about it, that those disgustingly familiar smells emanate from comets. Their cousins, meteors, are local—hanging around Mars and Jupiter—while comets could schlep these odors in from as far away as the Oort cloud, the outer limit of our solar system, which makes sense, since "Oort cloud" kind of sounds like a name for a fart.

To better understand what's going on up there, I decided to mix up a batch of comet funk and smell it. I reached out to Kathrin Altwegg, the principal investigator for ROSINA, to see if I'd be putting my life at risk in this noble pursuit of scientific truth. "I think it's fun to mix this, and we are actually doing something similar for the event we will have in our institute," she told me. With the blessing of a bona fide scientist in my pocket, I set to work collecting the ingredients I'd need as though I were taking part in the most idiotic RPG quest ever (although I skipped the formaldehyde since it was the one carcinogenic part of the formula).

First, I'd need to find some rotten eggs. A sign of smooth sailing ahead, a friend immediately responded to my online call for help saying she'd just left a dozen eggs out for a few days while she was out of town. I scooped those up first so as to let them age a bit more while I gathered everything else.

Some of the basic ingredients like almond extract and vinegar were easy to pick up. But I needed that horse stable smell to fully capture the stench the ROSINA crew had promised me. The closest thing to a horse stable I could find was the pony ride attraction in LA's Griffith Park. I sidled up to one of the employees manning the line of little kids waiting for rides and made my proposition: "Hey, man. This might sound weird, but is there any way I could scoop up some hay or dirt with pony pee on it?"


The guy was completely unfazed. He asked his superior if I could get in the cage to grab a sample, and the boss told me, "Sure, buddy. We get requests for this stuff all the time. You're not the first to ask." I made a mental note to look into that later, and scooped up some trampled turds that I'd just seen one of the ponies piss all over.

Moving to a new area of the park (because fuck doing this in my apartment), I lined a waste bin with a garbage bag and started mixing the potion with a stick. The horse piss didn't have quite the ammonia punch I was hoping for, so in the interest of data-gathering, I added a big splash of regular cleaning ammonia to the mix.

Eggs were dropped in whole and broken with the stick. The other liquids were added. Finally, a bottle of water was poured in to help mix everything together. Ms. Altwegg herself had nudged me in the direction of H2O, pointing out that comets were mostly ice, after all.

I leaned in for my first whiff. The odor was funky and a bit acrid, but never tipped the scale into downright wretch-inducing territory. There was an antiseptic tinge to the whole thing from the ammonia. Like the weird dirty-clean smell of a hospital but with the dial turned way up. It had a certain beer smell, though not a brewery as much as the bottom of your shoes after a night shuffling around a college bar. All in all, it smelled like science took a shit, but to me, not a nightmarishly stinky one. I'd need other opinions.


I ran to my car, grabbed a piece of paper and a Sharpie, and scrolled on it: "SMELL A COMET!!!" I taped the sign to my can in the hopes of luring in some adventurous park-goers.

It worked. A couple girls stopped and I explained what was going on. "I'll tell you what's in it after you smell," I promised. "It's not anything that's going to cause you harm, but you probably won't like it."

Surprisingly, the girls stuck their heads over the can and inhaled.

"I don't smell anything," the first said.

"You have to get deep in there."

She pushed her face farther into the can.

"Ugh. What is that? I'm going to vomit."

"It's a comet!"

The second took her sniff and I went through the grocery list with them and thanked them for their intrepid spirits. They went on their way and I flagged down a jogger who had started his walking break.

"Would you be interested in smelling a comet? I'm getting people's interpretations for a research project," I said, not exactly lying. We went through the same motions as with the girls, and he left a bit nonplussed, probably wishing he hadn't done the thing I asked him to do.

Another guy came by and wanted to know if he could pick up the bucket to get closer, see what the turds of space really smell like. By all means, friend. Get in there. He pulled his head out and made a scrunched up face and had a little dry heave.

"Uhh. Yeah. OK. Yeah. That was pretty unpleasant. Thank you."

Strangers were now thanking me for coercing them into smelling horse piss. I didn't even have a camera crew or anything remotely official-looking to lend me any credibility. All I had was bucket of dirt, horse pee, and rotten eggs with a hand-written sign taped onto it. You're incredibly trusting, Angelenos.

After an older man and a middle-aged woman had their turn with the comet bucket, I decided to pack it in. Maybe I wasn't going to change anyone's life for the better with my research—in fact, for a while there I was actively trying to make some people's days a teensy bit worse—but Professor Altwegg thought I was all right, and that was enough for me. I threw out the garbage bag of swill and left to go see Interstellar.

Follow Justin Caffier on Twitter.