In short, there is no way to tell the difference between alien minerals and alien life.
That's why I was asking the question. I suspect that for every non-anthropomorphic definition of life there is a handy counter-example out there.
The most noticeable difference between Earth and Mars at interstellar distances is EM radiation, most of which is directly created by iron-based artifacts.
I am not sure whether this is an invalid point of view. Or that humans are the latest generation of machines designed to preserve and proliferate mitochondria. Or any other outside view of life.
It's not likely that we will encounter something like anything we have thought of, because can think of a trivial number of the possibilities.
Today's post, Humans in Funny Suits was originally published on 30 July 2008. A summary (taken from the LW wiki):
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This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Interpersonal Morality, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
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