Pas d'anciennes civilisations extraterrestres alentours

Professor Michael Garrett (ASTRON & University of Leiden) has used radio measurements of the very best candidate galaxies and discovered that the vast majority of these systems present emission that is best explained by natural astrophysical processes. In particular, the galaxies as a sample, follow a well-known global relation that holds for almost all galaxies — the so-called “mid-infrared radio correlation.” The presence of radio emission at the levels expected from the correlation, suggests that the mid-IR emission is not heat from alien factories but more likely emission from dust — for example, dust generated and heated by regions of massive star formation.

Advanced Alien Civilizations Rare or Absent in the Local Universe
Astrobiology Magazine