Re:Earth-like lights (Score 2)

Learn some science.

Neither volcanoes nor streetlights put out .01% as much light as the sun.

Which according to your comment would mean that the light difference is only 20dB down in power from the starlight.
Additionally, the planet's light spectra would be different than the light spectra of the star.
Combine these two facts and I believe his question still stands even if he doesn't "know science".
Would the sensor be able to detect the difference?
If background noise at the telescope is at -120dBm (or less with cooling), then is it possible to detect a difference at a specific frequency?