how far are we from detecting a moon around an earth sized planet in another star system? i read an article recently (http://www.newscientist.com/article...e-sun-and-moon-the-same-size-in-the-sky.html") about how the moon being so close to earth wasn't, or doesn't appear to be, a very likely event. since there was a low probability of our planet having our moon it seems it was actually important for life to form here in the first place (tides, etc...). it got me wondering how far technology has to develop in order to find a planet the same size of earth, in the same type of orbit, around an identical star to the sun, with a moon the same size of earths on the same type of orbit? do we need to detect the moon? what comes first, detecting wavelengths of light reflected from the surface of the planet, or detecting a planets wobble due to its moon? if we could detect light from the planets surface would we be able to detect any plant life etc? what about detecting oxygen in the atmosphere? i cant think of anything more exciting than detecting these kind of things and am basically wondering how much we will find out, and the likelihood we will find strong evidence of extra terrestrial life, within my lifetime.