Voyager 1 Most Distant Object Created by Humans

In September 1977 a little robotic spacecraft named Voyager I left the Earth to begin a tour of the solar system.  Today the Little Spaceship that Could is still out there, still flying, still sending back data and about to "leave our solar system"

That last phrase is in quotes because there is no clear dividing line between what is defined as IN and OUT of the solar system.  

The following article by Jason Major (article appeared on the Universe Today website) is a great discussion on what clues scientists will look for in Voyager's data.  

Voyager 1, Is It In or Is It Out? by Jason Major

Has Voyager 1 actually left the Solar System? Some researchers are saying yes. (Image: NASA/JPL-Caltech)