- First Light (After the Big Bang) – finding and studying the first luminous objects: proto-galaxies, supernovae and black holes;
- Assembly of Galaxies – studying the merging of proto-galaxies, the effects of black holes and the history of star formation;
- Birth of Stars and Planetary Systems – studying how stars form in dust clouds, and how chemical elements are produced and recirculated;
- Planetary Systems and the Origins of Life – studying the formation of planets and obtaining direct observations of other planetary systems, as well as study of the outer Solar System.
Although the first two of these themes are extragalactic in nature and concerned with exploring the formation of stars and galaxies in the remote Universe at the earliest times, they are intimately linked to the latter two mainly Galactic themes, which aim at understanding the detailed process of star and planet formation in our own Galaxy.