The Herschel craft is designed to look at infrared radiation emitted by galaxies, stars, planets and comets. With a mirror 3.5 metres in diameter, it is the biggest space telescope ever launched. By studying infrared light, Herschel will be able to see more clearly through clouds of dust and get a better view of star and galaxy formation. It will also examine the dust ejected by dying stars and analyse in more detail the composition of comets and planets in our own solar system.
The Planck craft will attempt to map the low-level radiation that still remains following the Big Bang over 13 billion years ago. By generating a pattern of this "Cosmic Microwave Background", scientists will be able to investigate how the structure of the modern Universe came to be, and to identify the ancient seeds of galaxies and galaxy clusters.
If you would like to find out more about the Herschel or Planck mission, click HERE.