Let's go back to space: Voyager 1

 

Check out Voyager 1's position here.

Voyager 1 was launched on Sept 5, 1977 and is currently still sending data back to Earth even in what is called interstellar space. It is the further man-made object away from Earth. 

Voyager 1 is further away from Earth than its sister probe Voyager 2 (launched August 20, 1977) and also Pioneer 10 and Pioneer 11 (currently derelict in space though also far away from Earth).

Both of the Voyager probes have golden records which I have linked to on this blog in the past. They were designed to be found by any extraterrestrial species that may run across these probes. The records are like time capsules and who knows they may well outlast human civilizations.

Of course here's the deal. While Voyager 1 at least has left the heliopause which is the boundary between the solar wind of our Sun and the plasma of other stars in our galaxy. So whatever instruments the probes still have and certainly whatever energy it has remaining has been used to collect data outside of our solar system.

Beyond the heliopause is a region known as the Oort cloud and Voyager 1 is expected to reach that area of space in about 300 years. Of course a lot can happen in that time, to Earth especially. And as a huge science fiction fan, I would expect that humanity could beat Voyager 1 to the Oort cloud well before that.

And it would take about 30,000 years to for the probe to pass through it. Again, it's possible that we may beat that probe through that area of space. That is unless "warp drive" - a future faster than light propulsion system actually being studied by physicists - becomes a reality and bridges the vast distances within our galaxy.

As far as any extraterrestrial visitors. Who knows? Perhaps the idea of a UFO - and thus alien visitors - are a reality. And it's also possible that any other advanced lifeforms like ourselves - humanity - might not have yet figured out how to bridge the vast distances in our galaxy as of yet. Who knows if as long as the Voyagers remain out there if they will encounter any other life forms.