ISLAMABAD        -       Visible matter – everything from pollen to stars and galaxies – accounts for roughly 15% of the total mass of the universe. The remaining 85% is made of something entirely different from things we can touch and see: dark matter. Despite overwhelming evidence from the observation of gravitational effects, the nature of dark matter and its composition remain unknown. How can physicists study dark matter beyond gravitational effects if it is practically invisible? Three different approaches are pursued: indirect detection with astronomical observatories, searching for the decay products of dark-matter annihilation in galactic centres; direct detection with highly sensitive low-background experiments, looking for dark matter scattering off nuclei; and by creating dark matter in the controlled laboratory environment of the Large Hadron Collider (LHC) at CERN. Although successful at describing elementary particles and their interactions at low energies, the Standard Model of particle physics does not include a viable dark-matter particle.