Allow me to explain. In your own words...
You act as if life capable of traveling vast distances to our tiny speck could not be carbon based.
Humans and ants are both carbon based. We don't try to make contact with ant colonies, but are more inclined to observe and study them.
The ants may know we exist, acknowledge our presence know they're powerless to do anything to or with us, and may know that we have the means to travel much greater distances at a much higher rate than they are capable of, but in the end ants and humans are both carbon based life forms.
So capability of travel doesn't make the basis of life mutually exclusive.
Humans honestly can't comprehend the vastness of the known universe, let alone our solar system and how small we are in tTHAT speck of the universe.
To go along with that, we simply don't know what it would take to travel across that vastness in a manner that would allow us to do so in our lifetime.
Just as the ant couldn't possibly travel across North America in it's lifetime.
Travelling across the country is nothing for us. To an ant - even if they were capable of comprehending the vast distance - it would seem an impossible task given their capabilities and knowledge.
So...
We are the ants.
I'm definitely not saying that there's not more (and more intelligent) life out there, I'm just saying that "it cannot be carbon based" isn't backed by anything other than the limits of OUR knowledge and technology.
This is the same as scientists looking for water on other planets because "water is essential for life".
Essential for life on our planet? Yes. But to make an assumption that there has to be water on other planets for life to exist on that planet shows just how little we actually know and how we're wrong for looking for life through that perspective.
We're still finding life on Earth, in places deemed inhospitable for life to exist, that's flourishing.
Our problem is that we're looking for life in space within our concept of what is needed for life.
All while being proven wrong about where life can/cannot exist here on Earth.