You must be thinking about some 100s or may be around a 1000 types. But you will be surprised to know the reality of human quality of smelling.

NASA has employed George Aldrich for nearly 40 years as its ‘Chief Sniffer’ to smell every object before they can be flown into a space shuttle. George can smell anything or almost everything.

Aldrich’s team tests nearly all items that astronauts would encounter during their flight including fabric, toothpaste, circuit boards, and the ink on their checklists.

Interestingly, Aldrich can detect more than 10,000 smells. For detailed report view the video below: