Thanks ;) I think that there are countless other planets just like ours out there with life similar to ourselves. However, I don't believe interstellar travel is possible in a physical sense... the space between stars is 'dead space'. If there has been physical alien life here, they would have to be here in our solar system. I think it's unlikely any forms such as ourselves exist on any other planet in the solar system... other types of lifeforms, sure, but not ones like us. Any other intelligent beings in the solar system probably wouldn't travel here because they likely wouldn't have enough in common with us to be interested. They could even be gaseous beings, or in some other type of formation that is not at all relatable to us.