One afternoon, I accidentally got off the wrong floor of my East Village apartment. Each floor in the building looked exactly the same, and yet, for some reason, I felt that something was amiss. Wait, it smells different, I thought.

Smell, the most underestimated and underappreciated of our senses, is everywhere. In Chandler Burr’s The Emperor of Scent, he tells the story of a woman to whom everything smelled vile. The condition, cacosmia, kept her indoors for years, until a doctor diagnosed her to have a form of epilepsy that was interfering with her olfactory bulb. Once given the proper medication, the woman could recall the specific moment when her sense of smell started to become normal. The room she was in started to change in perspective, as though it were moving. It seems that smell affects our sense of space.

Curiously, things that we may not immediately attribute smells actually give off odors. Here are some examples:

1. Rain

Can you smell when a storm is coming?

You know when you (or animals) can “smell” that rain might come? Well, it turns out that you’re not imagining it. Rain does give off a smell; three of them, in fact. These are ozone, petrichor, and damp earth, according to Daisy Yuhas of Scientific American.

(HT @sciam)

2. Space

Space can remind astronauts of steak, metal and welding fumes, among other things.

Perhaps “ordinary” isn’t the word I would use for space, but it’s quite fascinating that something that primarily awes us visually can also smell otherworldly. Megan Garber of The Atlantic reports that astronauts describe the smell of space in various ways, such as “seared steak,” “hot metal,” and “welding fumes.”

3. Tumors

Dogs as cancer detectors

Dogs, whose sense of smell is 100,000 times more sensitive than that of humans. Last year, German researchers reported that dogs can detect the smell of cancer, specifically lung cancer. When cells start to mutate because of the disease, they give off volatile odors that dogs can detect.

Hacking into olfaction

Scientists are increasingly finding ways to elucidate the complex process of olfaction. In 2010, Harvard scientists engineered mice that were capable of “smelling light.” The same year, German scientists also engineered flies that were capable of perceiving light for unpleasant smells.