why are they looking for another solar system?  

I think there are two answers to this question. The first would be because it's human nature to be curious, as far as we can tell humans have always been curious as to cause and effect, especially when it comes to the sky, we've been studying the planets and stars since records have been made. What causes the moon to stay in orbit. Is a good example.
The next would be a little more far fetched. I'm 61 yrs. and the advance in life in the USA has gone from good to the best, by that I mean, say the telephone, when I was young we had a party line? You probably don't even know what I'm talking about, but the phone was shared with other people in town, we had to wait to make a call if someone in town was using the line. Now we got cell phones, this still to this day amazes me! My point is the advancement in technology has been tremendous in the last 50 years. So we can't even imagine what it will be like in the next 50 years. So there is a great possibility, in the near future we will be able to go to a planet and ruin it, just like we did this one! tdemex

you're gettin' scientific now huh? i hope you could provide more details. i haven't heard that. looking forward to your additional inquiries.

Well, if we don't find a way to stop global warming and fixed the mess that we have done in this planet, probably Earth would not be able to support life after this century. that's Scientist are making an advance study and more over a planned exploration some day when we have the technology to travel planets. for now, those future astronauts are nothing more than just elementary students of today.

maybe., havent seen that part of discovry? who knows there could be... and they really are doing it...