The SONG project will focus on the study of the internal structure and evolution of stars and search for and characterise planets with masses comparable to the Earth in orbit around other stars than the Sun. SONG will do so by building a network of 1m telescopes placed in carefully selected locations around the Globe.
One of the main ideas behind SONG was to dedicate telescopes to observe single targets for a very long period of time. This is needed to do asteroseismic investigation of stars where oscillations on the surface of stars are analysed.
With a complete network it will be possible to follow single targets 24 hours a day for weeks or even months. In practice this means that one telescope takes over when the Sun rises in one place and has set in the other. To do this from Earth a minimum of 3-4 telescope on each hemisphere is needed to cover the entire sky.
The SONG prototype is built and in operation at Observatorio del Teide on the Canary island of Tenerife.