Thread: Gliese 667C

Up to now, astronomers have detected 4.157 exoplanets (of which 873 are confirmed, i.e. a confidence level of 99.9999%).
On the list, the planets of Gliese 667C are mentioned.

This triple-star system contains 5 planets (two other signals are not yet confirmed). Of the five planets, there are:

"(...) three rocky planets in the star's habitable zone, where temperatures should suit life.(...) These three worlds are close enough to each other that any intelligent life there with the ability to build rockets could easily visit the neighbours."

Of course, if the people are informed about these recent findings, then one can ask if there is life on those planets.
In order to answer that question, scientists could (and will) scan the exoplanets for life.

But my question is: how do you scan for life?
And how do we know that we detect life if we only measure with the characteristics of terrestrial life in mind?
(e.g. looking for amino acids, when it is possible that other life forms do not use them)


Sources:
PlanetQuest - The Search for Another Earth
Three habitable worlds found around the same star - space - 25 June 2013 - New Scientist
http://www.eso.org/public/archives/r...8/eso1328a.pdf

Right now I don't think we can scan for life, at a bare minimum you would need to be able to do direct spectroscopy of the planet in question to pick up the tell-tail signs in the atmosphere. There were plans a while ago for an array of telescopes in space where one could use interferometry to resolve the exoplanets but I don't think it got very far beyond the planning stage.

Here's a nice video that explains the Gliese 581 Planetary System