[idlewords]

A different stab at this is to ask what it would take to build a telescope that could image some of these Earth-like planets, a project that turns out to be easier (in a very loose sense of that word) than sending cameras there.

The idea is you send a camera very, very far out in the Solar System (hundreds of AU) and then use the Sun's gravity well as your lens. Neat stuff and, unlike the interstellar probes, potentially doable in our lifetime.

https://en.wikipedia.org/wiki/Solar_gravitational_lens

[rocqua]

Normally, diffraction and the effective aperture are what limit optical resolution. How does that work with gravitational lensing? Does the effective aperture become the diameter of the sun?

[idlewords]

I'm too ignorant to answer that, but the technical paper here [https://arxiv.org/pdf/2002.11871] goes into a wealth of detail, and includes an image of Earth as it would appear to such a telescope (before and after post-processing) from 30 parsecs away. The optical properties of the solar gravitational lens are pretty astonishing.