Terraforming of Exoplanets

In context of an interview by highschool students I had to answer some questions in regards to terraforming of exoplanets. This interview included topics such as detection of earth like planets, possible space travel scenarios to those planets and ethical implications of inhabiting new worlds.

The question went a bit further than what I am working on, but nevertheless it was fun thinking about all this stuff. In my believe we have a real chance to find a planet similar to earth and to be able to detect first hints for extrasolar live (if it exists) in exoplanets atmospheres in the next 20-50 years. Everything beyond this point is pure speculation.

With projects such as StarShot we might be able in a next step (another 50 years maybe?) to send nanoprobes to those places. But already sending such nanoprobes is at the moment out of reach and needs lots of new technology.  This makes it hard to go any further in speculation.