(August 28, 2012 at 1:56 am)teaearlgreyhot Wrote: I read somewhere that we might have telescopes powerful enough in 50 years to actually see these planets in detail.
The first challenge is direct imaging - being able to resolve the planetary disk from it's host star (which is many orders of magnitude brighter). We already have the technology to mask out the stellar disk.
Interferometry will be a big help here - the basic idea is that you use two (or more) telescopes. Doing so increases the light-gathering capability additively, but the angular resolution possible is a function of the distance between the telescopes (e.g. two telescopes 100m apart potentially has the angular resolution of a telescope with a 100m wide objective mirror/lens).
Earth-based interferometry is limited - by atmospheric distortion, as well as by practical limits on separation. However - imagine a space-based interferometer with objectives located millions of miles apart.... Fairly modest telescopes could be capable of angular resolution many many orders of magnitude more than what we have accomplished so far. This isn't blue-sky technology either - it's within reach today.
I don't know about detailed "images" - but using interferometry in conjunction with spectroscopy will tell us a lot about the composition of extrasolar planets, particularly the chemical composition of the atmosphere. We can deduce a lot from atmospheric composition, including whether or not life (as we know it) is likely present.
It'll happen - but before we can get really serious about it, we'll need a large list of targets, such as those that discovered by the Kepler mission.
It's an exciting time.
