<p>The properties of dark matter — its microphysical form, and its cosmological origin and history — are one of the most important mysteries in fundamental physics. So far, evidence for matter beyond the Standard Model comes entirely from gravitational effects. However, other experiments are reaching the point where the ‘simplest’ models of dark matter are coming into tension with data, and may be strongly constrained by medium-term observations. This, along with theoretical considerations, motivates the exp…