Hacker News Reader

My understanding based on their use of "technology similar to ours" is that this is exactly what they're doing:

>If an extraterrestrial civilization existed with technology similar to ours, would they be able to detect Earth and evidence of humanity? If so, what signals would they detect, and from how far away?

View on HN

I was thinking we probably can't watch the whole sky in maximum detail all at once, so in practice we'll miss most possible detections.

They could get a 25km high-resolution picture of the planet? https://en.wikipedia.org/wiki/Solar_gravitational_lens

The caveat "with technology similar to ours" precludes that, I think.

We know how to do that, but we also know how to build an O'Neill cylinder, a phased array optical telescope covering the surface of the moon, or an orbital ring — but practical considerations mean we actually can't.

Reply on news.ycombinator.com