What does space smell like? It’s strange to think that the near-vacuum of space could have a smell, and stranger still that humans—atmospheric creatures—can actually experience it. Astronauts have consistently reported the same strange odour after lengthy space walks, bringing it back in on their suits, helmets, gloves and tools. It’s bitter, smoky, metallic smell—like seared steak, hot metal and arc welding smoke all rolled into one. NASA have asked a chemist, Steve Pearce, to reproduce the smell to use during acclimatization training, mapping out the likely chemistry using natural materials to mimic the odor for accuracy. It’s believed that the smell is caused by high-energy vibrations in particles that mix with the air when brought inside. In the future, we might even recreate the smell of the moon, Mars, Mercury or any place in the universe, provided we have the right chemical information. In fact, we can even recreate the smell of the heart of the galaxy—astronomers searching for animo acids in Sagittarius B2, a vast dust cloud in the middle of the Milky Way, have reported that due to a substance called ethyl formate, it smells and tastes of raspberries and rum—much more pleasant than seared steak and metal. Read an interview with Steve Pearce