My first reaction: LOL! Those "aliens" are probably sophisticated people who have been watching us for light years and making fun of how far behind we are in science. The call us the aliens and would prefer to stay 600 light years away.
My second reaction: Hmm, when are they going to offer rides between here and this new planet? Earth is getting pretty dirty, it's full of bad people, wars, and destructive human behavior. It's only a matter of time before we need to go there and ruin another planet. Maybe I can get there first so I can see it before that happens.
Way to go, NASA - it quite amazing how we can find these things. Let's hope mankind does not destroy this new planet!