How large of a telescope would one need in order to read someone's lips on a planet light years away?

If I wanted to image an Earth-like planet at a resolution where one could read the lips of a human speaking on the surface 1, 10, and 1000 light years away, how large would the telescope reflector need to be (the diameter) in each case?

Another way to ask my question is: Given a parabolic mirror/reflector the size of, say Earth's orbit, what would be the farthest distance one could read someone's lips or read printed text (a secondary concern would be imaging the entire face of the planet at such resolution)?

Assume the telescope is in space (no atmospheric interference) and outside of any asteroid belts or dust clouds, etc. I understand the mirror would have to track the movement of the planet.

My main objective is to get a layman's grasp of the relationship between the size of a telescope's reflector and its ability to see small details very far away. How big of an image can it produce and at what level of detail?

posted almost 8 years ago

HighTechGeek‭

1 reputation 1 0 0 0