Why does space smell like seared steak?" #chemistry #experiment #space #astrochemistry #astronomy

Added: 2026-05-25

Astronauts report smelling metallic and burnt odors after spacewalks due to Polycyclic Aromatic Hydrocarbons (PAHs)—carbon-based molecules abundant in space that are created when stars die or undergo energetic processes. These same compounds are produced on Earth when food like steak is seared or when fuel burns. The specific 'steakhouse' or 'welding fume' aroma astronauts experience is actually caused by ozone (O₃) formed when high-energy atomic oxygen from space suits interacts with fresh oxygen during airlock repressurization, combined with surface contamination from space dust and particles.