Abstract

One of the most exciting developments in astronomy is the discovery of planets around stars other than our Sun. More than 500 exo-planets have now been detected. But how do these planets form, and why are they so different from our own solar system? Which ingredients are available to build them? Thanks to powerful new telescopes, in particular the Herschel Space Observatory and pioneering millimeter interferometers, astronomers are starting to address these age-old questions scientifically. In this talk, an overview will be given of how stars and planets are born in the extremely cold and tenuous clouds between the stars in the Milky Way. Special attention will be given to the formation of protoplanetary disks in the embedded phase and their evolution. These clouds also contain water and a surprisingly rich variety of organic material. How and where was the water formed that is now in our oceans on Earth? Can these organic molecules end up on new planets and form the basis for pre-biotic material and eventually life? The Atacama Large Millimeter/Submillimeter Array (ALMA), under construction in Chile and planned to be fully operational in 2013, will be able to zoom into the planet-forming zones of disks around young stars and revolutionize this field in the near future.