The future of American space exploration may look more depressing than ever these days, between NASA budget cuts and a general disregard for science amongst chunks of the population. But the wonders are still out there, and amazing things are happening all the time if only we bother to pay attention. Case in point: Astronomy Now points out that the Voyager 1 spacecraft, launched by NASA back in 1977, is currently cruising along almost 11 billion miles from the Sun, on the threshold of entering the interstellar void. For the first time in history, a man-made object will leave our Solar System entirely. How cool is that?
Ironically, Voyager 1 completed its primary mission all the way back in 1980, sending back extensive photographs and data about Jupiter, Saturn, and their respective moons. With its last planetary close encounter behind it, Voyager has since been drifting ever further, headed for the outer edge of the Solar System. The craft is now on the edge of the heliosphere, the “bubble” surrounding the solar system created by charged particles emanating from the Sun. The latest data shows that Voyager has entered a “region of stagnation, where the stream of charged particles from the sun has slowed and the sun’s magnetic field has piled up.”
Rob Decker, a co-investigator for Voyager’s low-energy charged particle instrument at the Johns Hopkins University Applied Physics Laboratory, explained it like this:
We’ve been using the flow of energetic charged particles at Voyager 1 as a kind of wind sock to estimate the solar wind velocity. We’ve found that the wind speeds are low in this region and gust erratically. For the first time, the wind even blows back at us. We are evidently traveling in completely new territory. Scientists had suggested previously that there might be a stagnation layer, but we weren’t sure it existed until now.
It’s hard to pinpoint when Voyager 1 will officially leave the Solar System. Voyager project scientist Ed Stone says the big moment could occur anytime from a few months to a few years from now. He explained that “we continue to find our models need to be improved as we learn more about the complex interaction between the solar wind and the interstellar wind.”
Assuming all goes as planned, scientists estimate Voyager 1 could have enough power to remain functional until 2025. Unless it’s picked up and modified by an advanced machine race, then pointed our back way. (Okay, okay, that was the Voyager 6, but still…)