Targets and SETI: Shared motivations, life signatures and asymmetric SETI

The argument proposed in this paper is that conventional assumptions which underpin SETI can be revised in ways which permit a more nuanced approach to the enterprise. It is suggested that sensible assumptions based on adventurous science include the notion that we can conjecture helpfully about what we can know about SETI, and that probably the Ells for which we are looking are sending signals to us because they know they are not alone, and are interested to help us learn that we are not alone. Additionally, existing work using Pulsars as Beacons for SETI is reviewed in the context of what we can now call asymmetric SETI, the term coined to reflect that we are merely seeking to determine what ETI already knows. (C) 2010 Elsevier Ltd. All rights reserved.