Our atmosphere is full of waves. Similar to waves in our oceans, these waves can be generated by different mechanisms, propagate over long distances, break into turbulence, and strongly control local conditions. Waves in the atmosphere exist on many scales from local perturbation to global patterns. Recent research has revealed that waves can link together different parts of our climate system over long distances. An important goal of the MATS satellite mission is to investigate waves in the atmosphere. MATS focuses in particular on atmospheric altitudes between 50 and 100 km, the so called mesosphere.