alt Hacker NewsIf they are at our current tech level, to "see" Earth, then Earth would need to pass in front of the Sun from their point of view. That means they would need to be somewhere in the same pane as the Earth's orbit.
If they are at our current tech level, to "see" Earth, then Earth would need to pass in front of the Sun from their point of view. That means they would need to be somewhere in the same pane as the Earth's orbit.
That's a transiting detection, there's other detection methods for exoplanets. Even a coarse grained survey with a ground based traditional telescope can find our solar system thanks to Jupiter's gravitational influence on the Sun. Doppler shift's in the Sun's spectra come from Jupiter tugging at it gravitationally. With interferometry and coronagraphy spectra of planets in our system can be gathered without needing to see our system edge-on. Then of course for aliens on the ecliptic there's transiting spectra of Earth.
The number of techniques for detecting exoplanets makes the Dark Forest concept silly. There's no hiding our solar system from alien observation. For dedicated observers (at the right distances) there's no hiding the existence of life, the Industrial Revolution, or above ground nuclear testing.