Is interstellar archeology possible?

Searching for signatures of cosmic-scale archeological artifacts such as Dyson spheres is an interesting alternative to conventional radio SETI. Uncovering such an artifact does not require the intentional transmission of a signal on the part of the original civilization. This type of search is called interstellar archeology or sometimes cosmic archeology. A variety of interstellar archeology signatures is discussed including non-natural planetary atmospheric constituents, stellar doping, Dyson spheres, as well as signatures of stellar, and galactic-scale engineering. The concept of a Fermi bubble due to interstellar migration is reviewed in the discussion of galactic signatures. These potential interstellar archeological signatures are classified using the Kardashev scale. A modified Drake equation is introduced. With few exceptions interstellar archeological signatures are clouded and beyond current technological capabilities. However SETI for so-called cultural transmissions and planetary atmosphere signatures are within reach.

► Interstellar archeological artifacts (IA) like Dyson spheres are alternatives to SETI. ► Most IA signatures are clouded and beyond current technological capabilities. ► A modified Drake equation is introduced to discuss these possibilities. ► Non-natural planetary atmospheric constituents may be observable in several decades. ► A speculative galactic signature is a “Fermi bubble” due to interstellar migration.