The aim of MONS is to obtain a detailed picture of the insides of stars by measuring the frequencies at which they pulsate, in exactly the same way that seismologists have used earthquakes to probe the interior of the Earth.
Stars pulsate in many different modes simultaneously, each with a slightly different period.
Each mode is a sound wave, so the periods give information about the sound speed inside the star. For example, during its life a star burns hydrogen into helium in its core. Thus, measuring pulsations and comparing with theory allows us to measure the ages of stars. The study of starquakes, a field known as asteroseismology, has until now been almost impossible because of interference from the Earth's atmosphere. We have already built electro-optical systems for European remote sensing satellite missions and have complex instruments in orbit today, built in Canberra.