No one really knows what dark matter is. We just think it exists. And we believe it makes up 85 per cent of all mass in the universe. So how do you solve the mystery of something that is currently unknowable?Enter SNOLAB. This underground, clean lab is located in Sudbury, Ontario, and researchers there are running experiments to try to solve this cosmic query. Decibel producer Madeleine White, along with Globe science reporter Ivan Semeniuk, go two kilometres underground to visit SNOLAB and bring you up to date on the lab’s quest to discover dark matter.Questions? Comments? Ideas? Email us at thedecibel@globeandmail.com