Could a civilization 600 light year away detect our planet and reveal its composition

To the guy above me, I had to correct your statement about us only using ten percent of our brains. That is simply not true. Humans utilize their entire brain. The idea that we only use 10% of our brains is pseudo science. If we only used 10% of our brain, then when we suffered trauma to certain areas of the brain the damage would be insignificant and would pose no threat. However, we know that trauma to any part of the brain causes the whole brain to suffer and poses huge risks. Knowing this disproves the idea that we only use 10% of our brains because if a portion of it is damaged then our whole bodies suffer. So we actually use most if not all of our brain.

Probably not yet, however in another 500 years from now, I think so. Then it will start to receive the early radio signal transmissions and may even be able to see the bright lights appearing during night time at the time of the industrial revolution. Prior to that, the Earth will look quite benign and uninteresting.

Maybe you are thinking of kepler 22b, it all depends if that civilization contains more advance technology than ours, because we as humans on earth can definitely not tell if there is life there or not with our telescopes or current space craft, and i am sure that if that civilization has the same telescopes as us or space crafts they would not be able to tell if our planet would contain life or not, it would have to be a civilization with advanced technology, maybe not a telescope but the ability of interstellar travel, something that is able to travel faster than the speed of light, something that could warp space and time bending it towards them, because even if they were able to travel at the speed of light it would take them 600 years to arrive here so they would need to bend space towards them, kinda like bringing their destination towards them without actual movement, but this is very advanced and even though it is mathematically possible no one is sure if there is a civilization capable of this.
Honestly i doubt that we are alone in this universe and im not a ufo nut, but considering we are a very stupid species who wages wars on each other because of religious and political differences and burns fossil fuels for energy i highly doubt that any advanced civilization with a much more advanced brain and technology would be interested in communicating with us, maybe they have watched us but i highly doubt they would want to communicate considering we are the ones who use 10 percent of our brains.

Yeah its certainly possible.

if they have the technology then yes