Spotting extrasolar civilisations on a par with us

"Maurice W" wrote
At the moment it appears we can use some technologies to imply the
existence of whopping big jovians near to their sun etc., but is it at
all realistic for there to be civilsation like us relatively near to
us, but us simply not having the technology to spot it?

Well, apart from listening for radio transmissions and looking for
laser beacons (Oprical SETI), neither of which have yet yielded,
as far as I am aware, the other major means of searching for life
is atmospheric spectroscopy, as employed recently when water was found
in the atmosphere of a hot planet orbiting close to its star. That
technique could also detect oxygen, CO2, methane, and other gases that
would hint at the presence of life.

However, bacteria, grass, and rats are all examples of life.
Intelligent life is another matter, and probably not trivial to
detect using the technique. Maybe it'd be possible to identify
gases that are by-products, or results, of industrial activity,
but the concentrations would likely be trace and undetectable.


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie