Voyager 1
Voyager 1
[A heading at the top of a white panel, then a line and below this 22 tally marks in two rows, four times five (three of these at the top) and then two extra.] Number of times Voyager 1 has left the Solar System

Voyager 1 is a U.S. space probe launched in 1977 to study the outer reaches of the Solar System and beyond. Popular press has on several occasions announced that it "has left the solar system" at each point when a boundary has been confirmed or a major event has taken place. This underscores the fact that there is no strictly defined and recognizable boundary of the solar system, or at least we haven't found one yet.
On the day of this comics release (2013-03-22) it was announced that Voyager 1 had entered a new region of space . At this point Voyager 1 had passed through the Heliopause and entered the Interstellar medium , although this latter was first confirmed about half a year later in September 2013.
The chart shows that Voyager 1 has left the Solar System 22 times, but in the title text only 16 are mentioned.
The title text lists several such possible boundaries, (and how many times Voyager 1 has passed them) together with fictive humorous ones:
See also Voyager over the “heliocliff,” but Solar System transition mysterious on Ars Technica.
About eight years later, Voyager 1 leaving the solar system was brought up again in 2414: Solar System Compression Artifacts .
[A heading at the top of a white panel, then a line and below this 22 tally marks in two rows, four times five (three of these at the top) and then two extra.] Number of times Voyager 1 has left the Solar System
