One of the Terrestrial Planet Finder (TPF) designs is based upon a constellation of optical telescope satellites organized as a nulling interferometer. The whole works would be located in one of the libration points between the Earth and Moon. Supposably the TPF could detect earth sized worlds orbiting other stars at about 1 AU. The TPF could also do atmospheric spectroscopy. If the TPF could detect ozone and methane together in the atmosphere then it's a slam dunk conclusion that the planet has biology.

Now I ask myself: Could an extremely clever astronomer build something like the TPF on the Earth or does Ma Nature say "No Way"?

Gary