Looks like this is it, folks: After a lot of false alarms, Voyager 1 has officially become the 1st man-made object to leave our cosmic backyard, venturing into the unknown depths of interstellar space –cue the Star Trek soundtrack.
OK, so why has this been so hard to determine? Let's have the JPL Voyager team explain it to us N00bs:
"We have been cautious because we're dealing with one of the most important milestones in the history of exploration," said Voyager Project Scientist Ed Stone of the California Institute of Technology in Pasadena. "Only now do we have the data — and the analysis — we needed."
Basically, the team needed more data on plasma, which is ionized gas, the densest and slowest moving of charged particles in space. (The glow of neon in a storefront sign is an example of plasma.) Plasma is the most important marker that distinguishes whether Voyager 1 is inside the solar bubble, known as the heliosphere, which is inflated by plasma that streams outward from our sun, or in interstellar space and surrounded by material ejected by the explosion of nearby giant stars millions of years ago. Adding to the challenge: they didn't know how they'd be able to detect it.
"We looked for the signs predicted by the models that use the best available data, but until now we had no measurements of the plasma from Voyager 1," said Stone.
Voyager's plasma sensor, which would have helped settle the debate more easily, stopped working in 1980. Hence the JPL were left to detect the plasma flow indirectly, by way of analizing the direction of the magnetic fields –the solar plasma would have a field emanating from the center of the heliosphere, whereas interstellar plasma would point from the opposite direction.
Add to it the fact that most computational models were just that: models calculated based on what the scientists were expecting to find, in contrast to how deep space particles actually behave –one thing Gene Roddenberry failed to tell us: "boldly going where no man has gone before" can often translate into lack of consensus on what you discover; but then the series would have turned into 40 minutes of dragging debate, with only 30 seconds or so for Kirk to rushedly kiss an Orion slave girl…
So, can we safely assume Voyager is now well on its way to becoming V'ger?
"What we can say is Voyager 1 is bathed in matter from other stars," Stone said. "What we can't say is what exact discoveries await Voyager's continued journey. No one was able to predict all of the details that Voyager 1 has seen. So we expect more surprises."
But hopefully not the kind of surprise that makes us realize we're all part of an interstellar Truman Show!
… Although you gotta admit, that would explain a lot of things.