What does space smell like?

Astronauts say it smells like gunpowder and burnt steak

It being a vacuum and all, space isn’t often thought of as having a scent of its own. And while no one has directly smelled outer space — exposure without a helmet would be fatal — many astronauts have reported that it smells like a mix of gunpowder and burnt steak. The odor is most noticeable after an astronaut returns to their spacecraft through the airlock and removes their helmet, at which point the lingering scent can be detected by both the astronaut who had been outside the ship and their crewmates who remained aboard.

It’s been theorized that the source of space’s scent is dying stars, which release molecules called polycyclic aromatic hydrocarbons — a chemical compound also found in coal, oil, and food — as they near the end of their existence. There’s even a cologne named “Eau de Space” based on the smell, which was originally synthesized by biochemist Steve Pearce at NASA’s behest to better prepare astronauts for every aspect of the job. Based on his interviews with astronauts who had been to space, Pearce described the aroma as “hot metal, burnt meat, burnt cakes, spent gunpowder, and welding of metal.”