It’s been the topic of some debate among solar system scientists. But analysis of new data from NASA’s Voyager 1 strongly suggests that the probe has left the ecosystem of the Sun and entered true interstellar space. Like all stars, the Sun blows bubble of energetic particles outward, forming, in this case, a roughly spherical envelope of plasma. At some point, scientists expected that the count of Solar- propelled particles per time period would drop and they would see a spike in galactic plasma, indicating that the solar wind has been damped by the prevailing breeze of the stars beyond. That theoretical boundary – researchers call it the “Heliopause” – has clearly now been crossed. In fact, the data indicate that Voyager 1 – which was launched on September 5th 1977, became Humanity’s first interstellar probe on or about August 25th of 2012 – a 36-year odyssey through the Solar System, across “eleven and a quarter” billion miles. On its quest, as part of NASA's Grand Tour, it took many measurements and close-ups of the kingdoms of Jupiter and Saturn… …and a “family portrait” of the planets… … of which the much-celebrated Pale Blue Dot photo is part. Sometime between 2025 and 2030, Voyager 1’s tiny nuclear generator will no longer be able to power any of its instruments. Should it ever be found, by another intelligent species, it carries a gold-plated multimedia disc with photos of life on Earth, spoken word greetings and a mash-up of music and sounds of its home planet. But the distance between stars is great and the probe is not headed towards any of the Sun’s nearest neighbors. So it is most likely, that the next beings to lay eyes on Voyager will be our descendents; …those that left Earth; …a truly “extra-terrestrial” intelligent species. For SPACE.com, I’m Dave Brody