This question already has an answer here:
Lets assume that a fictitious planet called Planet L is 10 light years away. Also,lets assume that it is inhabited by fictitious aliens.These fictitious aliens have high resolution telescope which can see planets and the components of its surface well away from 20 light years.So , if these aliens turn their telescopes to our direction,will they see what was 10 years ago [since earth is 10 light years away from planet L]. If not , then what will they see ? This question is completely under fictitious circumstances.