INTRODUCTION.- Where are everyone?.- The phases and challenges.- Part I - The astronomical parameters NS, NP and FS.- 1st Drake: The star number of the galactic disc for stars of spectral class K, G and F.- 2nd Drake: number number per star, suitable for life in the habitable area (spectral class F, G and K).- 3rd Drake: fraction of stable planets for 7 gy (duration of the stellar population).- Part II - The biological parameters of Drake: fl and fi.- 4th Drake: the transition from non-living to the living.- 5th Drake: the probability of intelligent life.- Macro-interval A: the crucial passage; The onset of the Eukaryotic Cell.- Macro-interval B: the second step; The birth of animals (Metazoi).- Macro-interval B: The "solution" of the intelligence deduced by the definition of Kardasëv, centered on energy by individual, and its birth within the metzoi (the Homo case).- The oxygen curve.- Part III- The social parameters of Drake: FC and FL.- 6th Drake: fraction of planets where life decides to communicate.- 7th Drake: temporal fraction lasting a civilization.- The complete Drake equation Still the paradox of Fermi (but in short, where are everyone?).- Winners and won in the Milky Way.- Identikit of two possible intelligent alien species.- Epilogue - The mercy of the cheetah.- Appendices.
