There is almost certainly life residing within our own solar system. It is just a matter of finding it. However, should we encounter sentient life outside of our own species, it is highly unlikely that it will share our moral inhibitions. The environment and history of that life is likely to be radically different from ours and that will dictate much of their moral thought.
It is a certainty that any spacefaring culture will be the apex predator of it's origin. Therefore, it will have advanced on aggression. How virulent the aggression will depend upon how hostile the native environment. Therefore, I would not depend on a warm and friendly first encounter. In fact, the first ship to make the discovery of such life will be unable to return home to avoid leading a potential conqueror back to Earth. That is, if they survive the initial encounter at all.
Our small footprint is a blessing and not one that should be exchanged for a larger presence until we have advanced sufficiently to defend ourselves.