Pt. I. Origins. Our origins
The beginning of everything
Origins of stars and planets
The origin of the elements
The origins of life
pt. II. The case of the Earth. History of the Earth
Extinctions
An inhabitable planet
The importance of continental drift
The Earth : a rare planet?
pt. III. In search of another Gaia. In search of ETI
The measurement
Appendix A. Astronomical observations
Appendix B. A few numbers
Conclusion.